linux-stable.git/include/net, branch v5.4.285 Linux kernel stable tree mac80211: Add support to trigger sta disconnect on hardware restart 2024-11-08T15:20:52+00:00 Youghandhar Chintala youghand@codeaurora.org 2022-03-08T11:53:24+00:00 130b34a204a585fabfa172b9bba90bec2a91d591 [ Upstream commit 7d352ccf1e9935b5222ca84e8baeb07a0c8f94b9 ] Currently in case of target hardware restart, we just reconfig and re-enable the security keys and enable the network queues to start data traffic back from where it was interrupted. Many ath10k wifi chipsets have sequence numbers for the data packets assigned by firmware and the mac sequence number will restart from zero after target hardware restart leading to mismatch in the sequence number expected by the remote peer vs the sequence number of the frame sent by the target firmware. This mismatch in sequence number will cause out-of-order packets on the remote peer and all the frames sent by the device are dropped until we reach the sequence number which was sent before we restarted the target hardware In order to fix this, we trigger a sta disconnect, in case of target hw restart. After this there will be a fresh connection and thereby avoiding the dropping of frames by remote peer. The right fix would be to pull the entire data path into the host which is not feasible or would need lots of complex changes and will still be inefficient. Tested on ath10k using WCN3990, QCA6174 Signed-off-by: Youghandhar Chintala <youghand@codeaurora.org> Link: https://lore.kernel.org/r/20220308115325.5246-2-youghand@codeaurora.org Signed-off-by: Johannes Berg <johannes.berg@intel.com> Stable-dep-of: 07a6e3b78a65 ("wifi: iwlwifi: mvm: Fix response handling in iwl_mvm_send_recovery_cmd()") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7d352ccf1e9935b5222ca84e8baeb07a0c8f94b9 ]

Currently in case of target hardware restart, we just reconfig and
re-enable the security keys and enable the network queues to start
data traffic back from where it was interrupted.

Many ath10k wifi chipsets have sequence numbers for the data
packets assigned by firmware and the mac sequence number will
restart from zero after target hardware restart leading to mismatch
in the sequence number expected by the remote peer vs the sequence
number of the frame sent by the target firmware.

This mismatch in sequence number will cause out-of-order packets
on the remote peer and all the frames sent by the device are dropped
until we reach the sequence number which was sent before we restarted
the target hardware

In order to fix this, we trigger a sta disconnect, in case of target
hw restart. After this there will be a fresh connection and thereby
avoiding the dropping of frames by remote peer.

The right fix would be to pull the entire data path into the host
which is not feasible or would need lots of complex changes and
will still be inefficient.

Tested on ath10k using WCN3990, QCA6174

Signed-off-by: Youghandhar Chintala <youghand@codeaurora.org>
Link: https://lore.kernel.org/r/20220308115325.5246-2-youghand@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Stable-dep-of: 07a6e3b78a65 ("wifi: iwlwifi: mvm: Fix response handling in iwl_mvm_send_recovery_cmd()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
genetlink: hold RCU in genlmsg_mcast() 2024-11-08T15:20:50+00:00 Eric Dumazet edumazet@google.com 2024-10-11T17:12:17+00:00 0d2bd44bfe06885762bbe89d0555204acdd9b84a [ Upstream commit 56440d7ec28d60f8da3bfa09062b3368ff9b16db ] While running net selftests with CONFIG_PROVE_RCU_LIST=y I saw one lockdep splat [1]. genlmsg_mcast() uses for_each_net_rcu(), and must therefore hold RCU. Instead of letting all callers guard genlmsg_multicast_allns() with a rcu_read_lock()/rcu_read_unlock() pair, do it in genlmsg_mcast(). This also means the @flags parameter is useless, we need to always use GFP_ATOMIC. [1] [10882.424136] ============================= [10882.424166] WARNING: suspicious RCU usage [10882.424309] 6.12.0-rc2-virtme #1156 Not tainted [10882.424400] ----------------------------- [10882.424423] net/netlink/genetlink.c:1940 RCU-list traversed in non-reader section!! [10882.424469] other info that might help us debug this: [10882.424500] rcu_scheduler_active = 2, debug_locks = 1 [10882.424744] 2 locks held by ip/15677: [10882.424791] #0: ffffffffb6b491b0 (cb_lock){++++}-{3:3}, at: genl_rcv (net/netlink/genetlink.c:1219) [10882.426334] #1: ffffffffb6b49248 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg (net/netlink/genetlink.c:61 net/netlink/genetlink.c:57 net/netlink/genetlink.c:1209) [10882.426465] stack backtrace: [10882.426805] CPU: 14 UID: 0 PID: 15677 Comm: ip Not tainted 6.12.0-rc2-virtme #1156 [10882.426919] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [10882.427046] Call Trace: [10882.427131] <TASK> [10882.427244] dump_stack_lvl (lib/dump_stack.c:123) [10882.427335] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) [10882.427387] genlmsg_multicast_allns (net/netlink/genetlink.c:1940 (discriminator 7) net/netlink/genetlink.c:1977 (discriminator 7)) [10882.427436] l2tp_tunnel_notify.constprop.0 (net/l2tp/l2tp_netlink.c:119) l2tp_netlink [10882.427683] l2tp_nl_cmd_tunnel_create (net/l2tp/l2tp_netlink.c:253) l2tp_netlink [10882.427748] genl_family_rcv_msg_doit (net/netlink/genetlink.c:1115) [10882.427834] genl_rcv_msg (net/netlink/genetlink.c:1195 net/netlink/genetlink.c:1210) [10882.427877] ? __pfx_l2tp_nl_cmd_tunnel_create (net/l2tp/l2tp_netlink.c:186) l2tp_netlink [10882.427927] ? __pfx_genl_rcv_msg (net/netlink/genetlink.c:1201) [10882.427959] netlink_rcv_skb (net/netlink/af_netlink.c:2551) [10882.428069] genl_rcv (net/netlink/genetlink.c:1220) [10882.428095] netlink_unicast (net/netlink/af_netlink.c:1332 net/netlink/af_netlink.c:1357) [10882.428140] netlink_sendmsg (net/netlink/af_netlink.c:1901) [10882.428210] ____sys_sendmsg (net/socket.c:729 (discriminator 1) net/socket.c:744 (discriminator 1) net/socket.c:2607 (discriminator 1)) Fixes: 33f72e6f0c67 ("l2tp : multicast notification to the registered listeners") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Chapman <jchapman@katalix.com> Cc: Tom Parkin <tparkin@katalix.com> Cc: Johannes Berg <johannes.berg@intel.com> Link: https://patch.msgid.link/20241011171217.3166614-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 56440d7ec28d60f8da3bfa09062b3368ff9b16db ]

While running net selftests with CONFIG_PROVE_RCU_LIST=y I saw
one lockdep splat [1].

genlmsg_mcast() uses for_each_net_rcu(), and must therefore hold RCU.

Instead of letting all callers guard genlmsg_multicast_allns()
with a rcu_read_lock()/rcu_read_unlock() pair, do it in genlmsg_mcast().

This also means the @flags parameter is useless, we need to always use
GFP_ATOMIC.

[1]
[10882.424136] =============================
[10882.424166] WARNING: suspicious RCU usage
[10882.424309] 6.12.0-rc2-virtme #1156 Not tainted
[10882.424400] -----------------------------
[10882.424423] net/netlink/genetlink.c:1940 RCU-list traversed in non-reader section!!
[10882.424469]
other info that might help us debug this:

[10882.424500]
rcu_scheduler_active = 2, debug_locks = 1
[10882.424744] 2 locks held by ip/15677:
[10882.424791] #0: ffffffffb6b491b0 (cb_lock){++++}-{3:3}, at: genl_rcv (net/netlink/genetlink.c:1219)
[10882.426334] #1: ffffffffb6b49248 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg (net/netlink/genetlink.c:61 net/netlink/genetlink.c:57 net/netlink/genetlink.c:1209)
[10882.426465]
stack backtrace:
[10882.426805] CPU: 14 UID: 0 PID: 15677 Comm: ip Not tainted 6.12.0-rc2-virtme #1156
[10882.426919] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[10882.427046] Call Trace:
[10882.427131]  <TASK>
[10882.427244] dump_stack_lvl (lib/dump_stack.c:123)
[10882.427335] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822)
[10882.427387] genlmsg_multicast_allns (net/netlink/genetlink.c:1940 (discriminator 7) net/netlink/genetlink.c:1977 (discriminator 7))
[10882.427436] l2tp_tunnel_notify.constprop.0 (net/l2tp/l2tp_netlink.c:119) l2tp_netlink
[10882.427683] l2tp_nl_cmd_tunnel_create (net/l2tp/l2tp_netlink.c:253) l2tp_netlink
[10882.427748] genl_family_rcv_msg_doit (net/netlink/genetlink.c:1115)
[10882.427834] genl_rcv_msg (net/netlink/genetlink.c:1195 net/netlink/genetlink.c:1210)
[10882.427877] ? __pfx_l2tp_nl_cmd_tunnel_create (net/l2tp/l2tp_netlink.c:186) l2tp_netlink
[10882.427927] ? __pfx_genl_rcv_msg (net/netlink/genetlink.c:1201)
[10882.427959] netlink_rcv_skb (net/netlink/af_netlink.c:2551)
[10882.428069] genl_rcv (net/netlink/genetlink.c:1220)
[10882.428095] netlink_unicast (net/netlink/af_netlink.c:1332 net/netlink/af_netlink.c:1357)
[10882.428140] netlink_sendmsg (net/netlink/af_netlink.c:1901)
[10882.428210] ____sys_sendmsg (net/socket.c:729 (discriminator 1) net/socket.c:744 (discriminator 1) net/socket.c:2607 (discriminator 1))

Fixes: 33f72e6f0c67 ("l2tp : multicast notification to the registered listeners")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Cc: Tom Parkin <tparkin@katalix.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Link: https://patch.msgid.link/20241011171217.3166614-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
mac80211: Fix NULL ptr deref for injected rate info 2024-11-08T15:20:49+00:00 Mathy Vanhoef Mathy.Vanhoef@kuleuven.be 2021-05-30T13:32:26+00:00 7526339f91ddcd1d4db64a3905d611282ca36bf1 commit bddc0c411a45d3718ac535a070f349be8eca8d48 upstream. The commit cb17ed29a7a5 ("mac80211: parse radiotap header when selecting Tx queue") moved the code to validate the radiotap header from ieee80211_monitor_start_xmit to ieee80211_parse_tx_radiotap. This made is possible to share more code with the new Tx queue selection code for injected frames. But at the same time, it now required the call of ieee80211_parse_tx_radiotap at the beginning of functions which wanted to handle the radiotap header. And this broke the rate parser for radiotap header parser. The radiotap parser for rates is operating most of the time only on the data in the actual radiotap header. But for the 802.11a/b/g rates, it must also know the selected band from the chandef information. But this information is only written to the ieee80211_tx_info at the end of the ieee80211_monitor_start_xmit - long after ieee80211_parse_tx_radiotap was already called. The info->band information was therefore always 0 (NL80211_BAND_2GHZ) when the parser code tried to access it. For a 5GHz only device, injecting a frame with 802.11a rates would cause a NULL pointer dereference because local->hw.wiphy->bands[NL80211_BAND_2GHZ] would most likely have been NULL when the radiotap parser searched for the correct rate index of the driver. Cc: stable@vger.kernel.org Reported-by: Ben Greear <greearb@candelatech.com> Fixes: cb17ed29a7a5 ("mac80211: parse radiotap header when selecting Tx queue") Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be> [sven@narfation.org: added commit message] Signed-off-by: Sven Eckelmann <sven@narfation.org> Link: https://lore.kernel.org/r/20210530133226.40587-1-sven@narfation.org Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit bddc0c411a45d3718ac535a070f349be8eca8d48 upstream.

The commit cb17ed29a7a5 ("mac80211: parse radiotap header when selecting Tx
queue") moved the code to validate the radiotap header from
ieee80211_monitor_start_xmit to ieee80211_parse_tx_radiotap. This made is
possible to share more code with the new Tx queue selection code for
injected frames. But at the same time, it now required the call of
ieee80211_parse_tx_radiotap at the beginning of functions which wanted to
handle the radiotap header. And this broke the rate parser for radiotap
header parser.

The radiotap parser for rates is operating most of the time only on the
data in the actual radiotap header. But for the 802.11a/b/g rates, it must
also know the selected band from the chandef information. But this
information is only written to the ieee80211_tx_info at the end of the
ieee80211_monitor_start_xmit - long after ieee80211_parse_tx_radiotap was
already called. The info->band information was therefore always 0
(NL80211_BAND_2GHZ) when the parser code tried to access it.

For a 5GHz only device, injecting a frame with 802.11a rates would cause a
NULL pointer dereference because local->hw.wiphy->bands[NL80211_BAND_2GHZ]
would most likely have been NULL when the radiotap parser searched for the
correct rate index of the driver.

Cc: stable@vger.kernel.org
Reported-by: Ben Greear <greearb@candelatech.com>
Fixes: cb17ed29a7a5 ("mac80211: parse radiotap header when selecting Tx queue")
Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
[sven@narfation.org: added commit message]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Link: https://lore.kernel.org/r/20210530133226.40587-1-sven@narfation.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: Fix an unsafe loop on the list 2024-11-08T15:20:47+00:00 Anastasia Kovaleva a.kovaleva@yadro.com 2024-10-03T10:44:31+00:00 8e0766fcf37ad8eed289dd3853628dd9b01b58b0 commit 1dae9f1187189bc09ff6d25ca97ead711f7e26f9 upstream. The kernel may crash when deleting a genetlink family if there are still listeners for that family: Oops: Kernel access of bad area, sig: 11 [#1] ... NIP [c000000000c080bc] netlink_update_socket_mc+0x3c/0xc0 LR [c000000000c0f764] __netlink_clear_multicast_users+0x74/0xc0 Call Trace: __netlink_clear_multicast_users+0x74/0xc0 genl_unregister_family+0xd4/0x2d0 Change the unsafe loop on the list to a safe one, because inside the loop there is an element removal from this list. Fixes: b8273570f802 ("genetlink: fix netns vs. netlink table locking (2)") Cc: stable@vger.kernel.org Signed-off-by: Anastasia Kovaleva <a.kovaleva@yadro.com> Reviewed-by: Dmitry Bogdanov <d.bogdanov@yadro.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20241003104431.12391-1-a.kovaleva@yadro.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1dae9f1187189bc09ff6d25ca97ead711f7e26f9 upstream.

The kernel may crash when deleting a genetlink family if there are still
listeners for that family:

Oops: Kernel access of bad area, sig: 11 [#1]
  ...
  NIP [c000000000c080bc] netlink_update_socket_mc+0x3c/0xc0
  LR [c000000000c0f764] __netlink_clear_multicast_users+0x74/0xc0
  Call Trace:
__netlink_clear_multicast_users+0x74/0xc0
genl_unregister_family+0xd4/0x2d0

Change the unsafe loop on the list to a safe one, because inside the
loop there is an element removal from this list.

Fixes: b8273570f802 ("genetlink: fix netns vs. netlink table locking (2)")
Cc: stable@vger.kernel.org
Signed-off-by: Anastasia Kovaleva <a.kovaleva@yadro.com>
Reviewed-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241003104431.12391-1-a.kovaleva@yadro.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: annotate lockless accesses to sk->sk_max_ack_backlog 2024-11-08T15:20:46+00:00 Eric Dumazet edumazet@google.com 2019-11-05T22:11:54+00:00 ed494a60503807eb7e659d0a3e7b3dfe3fe67ffb [ Upstream commit 099ecf59f05b5f30f42ebac0ab8cb94f9b18c90c ] sk->sk_max_ack_backlog can be read without any lock being held at least in TCP/DCCP cases. We need to use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing and/or potential KCSAN warnings. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: 4d5c70e6155d ("sctp: ensure sk_state is set to CLOSED if hashing fails in sctp_listen_start") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 099ecf59f05b5f30f42ebac0ab8cb94f9b18c90c ]

sk->sk_max_ack_backlog can be read without any lock being held
at least in TCP/DCCP cases.

We need to use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing
and/or potential KCSAN warnings.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 4d5c70e6155d ("sctp: ensure sk_state is set to CLOSED if hashing fails in sctp_listen_start")
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: annotate lockless accesses to sk->sk_ack_backlog 2024-11-08T15:20:46+00:00 Eric Dumazet edumazet@google.com 2019-11-05T22:11:53+00:00 e9b8a2629e051370a2613d323a5bc9fafb769e72 [ Upstream commit 288efe8606b62d0753ba6722b36ef241877251fd ] sk->sk_ack_backlog can be read without any lock being held. We need to use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing and/or potential KCSAN warnings. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: 4d5c70e6155d ("sctp: ensure sk_state is set to CLOSED if hashing fails in sctp_listen_start") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 288efe8606b62d0753ba6722b36ef241877251fd ]

sk->sk_ack_backlog can be read without any lock being held.
We need to use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing
and/or potential KCSAN warnings.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 4d5c70e6155d ("sctp: ensure sk_state is set to CLOSED if hashing fails in sctp_listen_start")
Signed-off-by: Sasha Levin <sashal@kernel.org>
net/sched: accept TCA_STAB only for root qdisc 2024-11-08T15:20:45+00:00 Eric Dumazet edumazet@google.com 2024-10-07T18:41:30+00:00 2acbb9539bc2284e30d2aeb789c3d96287014264 [ Upstream commit 3cb7cf1540ddff5473d6baeb530228d19bc97b8a ] Most qdiscs maintain their backlog using qdisc_pkt_len(skb) on the assumption it is invariant between the enqueue() and dequeue() handlers. Unfortunately syzbot can crash a host rather easily using a TBF + SFQ combination, with an STAB on SFQ [1] We can't support TCA_STAB on arbitrary level, this would require to maintain per-qdisc storage. [1] [ 88.796496] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 88.798611] #PF: supervisor read access in kernel mode [ 88.799014] #PF: error_code(0x0000) - not-present page [ 88.799506] PGD 0 P4D 0 [ 88.799829] Oops: Oops: 0000 [#1] SMP NOPTI [ 88.800569] CPU: 14 UID: 0 PID: 2053 Comm: b371744477 Not tainted 6.12.0-rc1-virtme #1117 [ 88.801107] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 88.801779] RIP: 0010:sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq [ 88.802544] Code: 0f b7 50 12 48 8d 04 d5 00 00 00 00 48 89 d6 48 29 d0 48 8b 91 c0 01 00 00 48 c1 e0 03 48 01 c2 66 83 7a 1a 00 7e c0 48 8b 3a <4c> 8b 07 4c 89 02 49 89 50 08 48 c7 47 08 00 00 00 00 48 c7 07 00 All code ======== 0: 0f b7 50 12 movzwl 0x12(%rax),%edx 4: 48 8d 04 d5 00 00 00 lea 0x0(,%rdx,8),%rax b: 00 c: 48 89 d6 mov %rdx,%rsi f: 48 29 d0 sub %rdx,%rax 12: 48 8b 91 c0 01 00 00 mov 0x1c0(%rcx),%rdx 19: 48 c1 e0 03 shl $0x3,%rax 1d: 48 01 c2 add %rax,%rdx 20: 66 83 7a 1a 00 cmpw $0x0,0x1a(%rdx) 25: 7e c0 jle 0xffffffffffffffe7 27: 48 8b 3a mov (%rdx),%rdi 2a:* 4c 8b 07 mov (%rdi),%r8 <-- trapping instruction 2d: 4c 89 02 mov %r8,(%rdx) 30: 49 89 50 08 mov %rdx,0x8(%r8) 34: 48 c7 47 08 00 00 00 movq $0x0,0x8(%rdi) 3b: 00 3c: 48 rex.W 3d: c7 .byte 0xc7 3e: 07 (bad) ... Code starting with the faulting instruction =========================================== 0: 4c 8b 07 mov (%rdi),%r8 3: 4c 89 02 mov %r8,(%rdx) 6: 49 89 50 08 mov %rdx,0x8(%r8) a: 48 c7 47 08 00 00 00 movq $0x0,0x8(%rdi) 11: 00 12: 48 rex.W 13: c7 .byte 0xc7 14: 07 (bad) ... [ 88.803721] RSP: 0018:ffff9a1f892b7d58 EFLAGS: 00000206 [ 88.804032] RAX: 0000000000000000 RBX: ffff9a1f8420c800 RCX: ffff9a1f8420c800 [ 88.804560] RDX: ffff9a1f81bc1440 RSI: 0000000000000000 RDI: 0000000000000000 [ 88.805056] RBP: ffffffffc04bb0e0 R08: 0000000000000001 R09: 00000000ff7f9a1f [ 88.805473] R10: 000000000001001b R11: 0000000000009a1f R12: 0000000000000140 [ 88.806194] R13: 0000000000000001 R14: ffff9a1f886df400 R15: ffff9a1f886df4ac [ 88.806734] FS: 00007f445601a740(0000) GS:ffff9a2e7fd80000(0000) knlGS:0000000000000000 [ 88.807225] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 88.807672] CR2: 0000000000000000 CR3: 000000050cc46000 CR4: 00000000000006f0 [ 88.808165] Call Trace: [ 88.808459] <TASK> [ 88.808710] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434) [ 88.809261] ? page_fault_oops (arch/x86/mm/fault.c:715) [ 88.809561] ? exc_page_fault (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:87 ./arch/x86/include/asm/irqflags.h:147 arch/x86/mm/fault.c:1489 arch/x86/mm/fault.c:1539) [ 88.809806] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:623) [ 88.810074] ? sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq [ 88.810411] sfq_reset (net/sched/sch_sfq.c:525) sch_sfq [ 88.810671] qdisc_reset (./include/linux/skbuff.h:2135 ./include/linux/skbuff.h:2441 ./include/linux/skbuff.h:3304 ./include/linux/skbuff.h:3310 net/sched/sch_generic.c:1036) [ 88.810950] tbf_reset (./include/linux/timekeeping.h:169 net/sched/sch_tbf.c:334) sch_tbf [ 88.811208] qdisc_reset (./include/linux/skbuff.h:2135 ./include/linux/skbuff.h:2441 ./include/linux/skbuff.h:3304 ./include/linux/skbuff.h:3310 net/sched/sch_generic.c:1036) [ 88.811484] netif_set_real_num_tx_queues (./include/linux/spinlock.h:396 ./include/net/sch_generic.h:768 net/core/dev.c:2958) [ 88.811870] __tun_detach (drivers/net/tun.c:590 drivers/net/tun.c:673) [ 88.812271] tun_chr_close (drivers/net/tun.c:702 drivers/net/tun.c:3517) [ 88.812505] __fput (fs/file_table.c:432 (discriminator 1)) [ 88.812735] task_work_run (kernel/task_work.c:230) [ 88.813016] do_exit (kernel/exit.c:940) [ 88.813372] ? trace_hardirqs_on (kernel/trace/trace_preemptirq.c:58 (discriminator 4)) [ 88.813639] ? handle_mm_fault (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 ./arch/x86/include/asm/irqflags.h:155 ./include/linux/memcontrol.h:1022 ./include/linux/memcontrol.h:1045 ./include/linux/memcontrol.h:1052 mm/memory.c:5928 mm/memory.c:6088) [ 88.813867] do_group_exit (kernel/exit.c:1070) [ 88.814138] __x64_sys_exit_group (kernel/exit.c:1099) [ 88.814490] x64_sys_call (??:?) [ 88.814791] do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) [ 88.815012] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) [ 88.815495] RIP: 0033:0x7f44560f1975 Fixes: 175f9c1bba9b ("net_sched: Add size table for qdiscs") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Link: https://patch.msgid.link/20241007184130.3960565-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3cb7cf1540ddff5473d6baeb530228d19bc97b8a ]

Most qdiscs maintain their backlog using qdisc_pkt_len(skb)
on the assumption it is invariant between the enqueue()
and dequeue() handlers.

Unfortunately syzbot can crash a host rather easily using
a TBF + SFQ combination, with an STAB on SFQ [1]

We can't support TCA_STAB on arbitrary level, this would
require to maintain per-qdisc storage.

[1]
[   88.796496] BUG: kernel NULL pointer dereference, address: 0000000000000000
[   88.798611] #PF: supervisor read access in kernel mode
[   88.799014] #PF: error_code(0x0000) - not-present page
[   88.799506] PGD 0 P4D 0
[   88.799829] Oops: Oops: 0000 [#1] SMP NOPTI
[   88.800569] CPU: 14 UID: 0 PID: 2053 Comm: b371744477 Not tainted 6.12.0-rc1-virtme #1117
[   88.801107] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   88.801779] RIP: 0010:sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq
[ 88.802544] Code: 0f b7 50 12 48 8d 04 d5 00 00 00 00 48 89 d6 48 29 d0 48 8b 91 c0 01 00 00 48 c1 e0 03 48 01 c2 66 83 7a 1a 00 7e c0 48 8b 3a <4c> 8b 07 4c 89 02 49 89 50 08 48 c7 47 08 00 00 00 00 48 c7 07 00
All code
========
   0:	0f b7 50 12          	movzwl 0x12(%rax),%edx
   4:	48 8d 04 d5 00 00 00 	lea    0x0(,%rdx,8),%rax
   b:	00
   c:	48 89 d6             	mov    %rdx,%rsi
   f:	48 29 d0             	sub    %rdx,%rax
  12:	48 8b 91 c0 01 00 00 	mov    0x1c0(%rcx),%rdx
  19:	48 c1 e0 03          	shl    $0x3,%rax
  1d:	48 01 c2             	add    %rax,%rdx
  20:	66 83 7a 1a 00       	cmpw   $0x0,0x1a(%rdx)
  25:	7e c0                	jle    0xffffffffffffffe7
  27:	48 8b 3a             	mov    (%rdx),%rdi
  2a:*	4c 8b 07             	mov    (%rdi),%r8		<-- trapping instruction
  2d:	4c 89 02             	mov    %r8,(%rdx)
  30:	49 89 50 08          	mov    %rdx,0x8(%r8)
  34:	48 c7 47 08 00 00 00 	movq   $0x0,0x8(%rdi)
  3b:	00
  3c:	48                   	rex.W
  3d:	c7                   	.byte 0xc7
  3e:	07                   	(bad)
	...

Code starting with the faulting instruction
===========================================
   0:	4c 8b 07             	mov    (%rdi),%r8
   3:	4c 89 02             	mov    %r8,(%rdx)
   6:	49 89 50 08          	mov    %rdx,0x8(%r8)
   a:	48 c7 47 08 00 00 00 	movq   $0x0,0x8(%rdi)
  11:	00
  12:	48                   	rex.W
  13:	c7                   	.byte 0xc7
  14:	07                   	(bad)
	...
[   88.803721] RSP: 0018:ffff9a1f892b7d58 EFLAGS: 00000206
[   88.804032] RAX: 0000000000000000 RBX: ffff9a1f8420c800 RCX: ffff9a1f8420c800
[   88.804560] RDX: ffff9a1f81bc1440 RSI: 0000000000000000 RDI: 0000000000000000
[   88.805056] RBP: ffffffffc04bb0e0 R08: 0000000000000001 R09: 00000000ff7f9a1f
[   88.805473] R10: 000000000001001b R11: 0000000000009a1f R12: 0000000000000140
[   88.806194] R13: 0000000000000001 R14: ffff9a1f886df400 R15: ffff9a1f886df4ac
[   88.806734] FS:  00007f445601a740(0000) GS:ffff9a2e7fd80000(0000) knlGS:0000000000000000
[   88.807225] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   88.807672] CR2: 0000000000000000 CR3: 000000050cc46000 CR4: 00000000000006f0
[   88.808165] Call Trace:
[   88.808459]  <TASK>
[   88.808710] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434)
[   88.809261] ? page_fault_oops (arch/x86/mm/fault.c:715)
[   88.809561] ? exc_page_fault (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:87 ./arch/x86/include/asm/irqflags.h:147 arch/x86/mm/fault.c:1489 arch/x86/mm/fault.c:1539)
[   88.809806] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:623)
[   88.810074] ? sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq
[   88.810411] sfq_reset (net/sched/sch_sfq.c:525) sch_sfq
[   88.810671] qdisc_reset (./include/linux/skbuff.h:2135 ./include/linux/skbuff.h:2441 ./include/linux/skbuff.h:3304 ./include/linux/skbuff.h:3310 net/sched/sch_generic.c:1036)
[   88.810950] tbf_reset (./include/linux/timekeeping.h:169 net/sched/sch_tbf.c:334) sch_tbf
[   88.811208] qdisc_reset (./include/linux/skbuff.h:2135 ./include/linux/skbuff.h:2441 ./include/linux/skbuff.h:3304 ./include/linux/skbuff.h:3310 net/sched/sch_generic.c:1036)
[   88.811484] netif_set_real_num_tx_queues (./include/linux/spinlock.h:396 ./include/net/sch_generic.h:768 net/core/dev.c:2958)
[   88.811870] __tun_detach (drivers/net/tun.c:590 drivers/net/tun.c:673)
[   88.812271] tun_chr_close (drivers/net/tun.c:702 drivers/net/tun.c:3517)
[   88.812505] __fput (fs/file_table.c:432 (discriminator 1))
[   88.812735] task_work_run (kernel/task_work.c:230)
[   88.813016] do_exit (kernel/exit.c:940)
[   88.813372] ? trace_hardirqs_on (kernel/trace/trace_preemptirq.c:58 (discriminator 4))
[   88.813639] ? handle_mm_fault (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 ./arch/x86/include/asm/irqflags.h:155 ./include/linux/memcontrol.h:1022 ./include/linux/memcontrol.h:1045 ./include/linux/memcontrol.h:1052 mm/memory.c:5928 mm/memory.c:6088)
[   88.813867] do_group_exit (kernel/exit.c:1070)
[   88.814138] __x64_sys_exit_group (kernel/exit.c:1099)
[   88.814490] x64_sys_call (??:?)
[   88.814791] do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1))
[   88.815012] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   88.815495] RIP: 0033:0x7f44560f1975

Fixes: 175f9c1bba9b ("net_sched: Add size table for qdiscs")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Link: https://patch.msgid.link/20241007184130.3960565-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp: check skb is non-NULL in tcp_rto_delta_us() 2024-11-08T15:20:33+00:00 Josh Hunt johunt@akamai.com 2024-09-10T19:08:22+00:00 16e0387d87fc858e34449fdf2b14ed5837f761db [ Upstream commit c8770db2d54437a5f49417ae7b46f7de23d14db6 ] We have some machines running stock Ubuntu 20.04.6 which is their 5.4.0-174-generic kernel that are running ceph and recently hit a null ptr dereference in tcp_rearm_rto(). Initially hitting it from the TLP path, but then later we also saw it getting hit from the RACK case as well. Here are examples of the oops messages we saw in each of those cases: Jul 26 15:05:02 rx [11061395.780353] BUG: kernel NULL pointer dereference, address: 0000000000000020 Jul 26 15:05:02 rx [11061395.787572] #PF: supervisor read access in kernel mode Jul 26 15:05:02 rx [11061395.792971] #PF: error_code(0x0000) - not-present page Jul 26 15:05:02 rx [11061395.798362] PGD 0 P4D 0 Jul 26 15:05:02 rx [11061395.801164] Oops: 0000 [#1] SMP NOPTI Jul 26 15:05:02 rx [11061395.805091] CPU: 0 PID: 9180 Comm: msgr-worker-1 Tainted: G W 5.4.0-174-generic #193-Ubuntu Jul 26 15:05:02 rx [11061395.814996] Hardware name: Supermicro SMC 2x26 os-gen8 64C NVME-Y 256G/H12SSW-NTR, BIOS 2.5.V1.2U.NVMe.UEFI 05/09/2023 Jul 26 15:05:02 rx [11061395.825952] RIP: 0010:tcp_rearm_rto+0xe4/0x160 Jul 26 15:05:02 rx [11061395.830656] Code: 87 ca 04 00 00 00 5b 41 5c 41 5d 5d c3 c3 49 8b bc 24 40 06 00 00 eb 8d 48 bb cf f7 53 e3 a5 9b c4 20 4c 89 ef e8 0c fe 0e 00 <48> 8b 78 20 48 c1 ef 03 48 89 f8 41 8b bc 24 80 04 00 00 48 f7 e3 Jul 26 15:05:02 rx [11061395.849665] RSP: 0018:ffffb75d40003e08 EFLAGS: 00010246 Jul 26 15:05:02 rx [11061395.855149] RAX: 0000000000000000 RBX: 20c49ba5e353f7cf RCX: 0000000000000000 Jul 26 15:05:02 rx [11061395.862542] RDX: 0000000062177c30 RSI: 000000000000231c RDI: ffff9874ad283a60 Jul 26 15:05:02 rx [11061395.869933] RBP: ffffb75d40003e20 R08: 0000000000000000 R09: ffff987605e20aa8 Jul 26 15:05:02 rx [11061395.877318] R10: ffffb75d40003f00 R11: ffffb75d4460f740 R12: ffff9874ad283900 Jul 26 15:05:02 rx [11061395.884710] R13: ffff9874ad283a60 R14: ffff9874ad283980 R15: ffff9874ad283d30 Jul 26 15:05:02 rx [11061395.892095] FS: 00007f1ef4a2e700(0000) GS:ffff987605e00000(0000) knlGS:0000000000000000 Jul 26 15:05:02 rx [11061395.900438] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jul 26 15:05:02 rx [11061395.906435] CR2: 0000000000000020 CR3: 0000003e450ba003 CR4: 0000000000760ef0 Jul 26 15:05:02 rx [11061395.913822] PKRU: 55555554 Jul 26 15:05:02 rx [11061395.916786] Call Trace: Jul 26 15:05:02 rx [11061395.919488] Jul 26 15:05:02 rx [11061395.921765] ? show_regs.cold+0x1a/0x1f Jul 26 15:05:02 rx [11061395.925859] ? __die+0x90/0xd9 Jul 26 15:05:02 rx [11061395.929169] ? no_context+0x196/0x380 Jul 26 15:05:02 rx [11061395.933088] ? ip6_protocol_deliver_rcu+0x4e0/0x4e0 Jul 26 15:05:02 rx [11061395.938216] ? ip6_sublist_rcv_finish+0x3d/0x50 Jul 26 15:05:02 rx [11061395.943000] ? __bad_area_nosemaphore+0x50/0x1a0 Jul 26 15:05:02 rx [11061395.947873] ? bad_area_nosemaphore+0x16/0x20 Jul 26 15:05:02 rx [11061395.952486] ? do_user_addr_fault+0x267/0x450 Jul 26 15:05:02 rx [11061395.957104] ? ipv6_list_rcv+0x112/0x140 Jul 26 15:05:02 rx [11061395.961279] ? __do_page_fault+0x58/0x90 Jul 26 15:05:02 rx [11061395.965458] ? do_page_fault+0x2c/0xe0 Jul 26 15:05:02 rx [11061395.969465] ? page_fault+0x34/0x40 Jul 26 15:05:02 rx [11061395.973217] ? tcp_rearm_rto+0xe4/0x160 Jul 26 15:05:02 rx [11061395.977313] ? tcp_rearm_rto+0xe4/0x160 Jul 26 15:05:02 rx [11061395.981408] tcp_send_loss_probe+0x10b/0x220 Jul 26 15:05:02 rx [11061395.985937] tcp_write_timer_handler+0x1b4/0x240 Jul 26 15:05:02 rx [11061395.990809] tcp_write_timer+0x9e/0xe0 Jul 26 15:05:02 rx [11061395.994814] ? tcp_write_timer_handler+0x240/0x240 Jul 26 15:05:02 rx [11061395.999866] call_timer_fn+0x32/0x130 Jul 26 15:05:02 rx [11061396.003782] __run_timers.part.0+0x180/0x280 Jul 26 15:05:02 rx [11061396.008309] ? recalibrate_cpu_khz+0x10/0x10 Jul 26 15:05:02 rx [11061396.012841] ? native_x2apic_icr_write+0x30/0x30 Jul 26 15:05:02 rx [11061396.017718] ? lapic_next_event+0x21/0x30 Jul 26 15:05:02 rx [11061396.021984] ? clockevents_program_event+0x8f/0xe0 Jul 26 15:05:02 rx [11061396.027035] run_timer_softirq+0x2a/0x50 Jul 26 15:05:02 rx [11061396.031212] __do_softirq+0xd1/0x2c1 Jul 26 15:05:02 rx [11061396.035044] do_softirq_own_stack+0x2a/0x40 Jul 26 15:05:02 rx [11061396.039480] Jul 26 15:05:02 rx [11061396.041840] do_softirq.part.0+0x46/0x50 Jul 26 15:05:02 rx [11061396.046022] __local_bh_enable_ip+0x50/0x60 Jul 26 15:05:02 rx [11061396.050460] _raw_spin_unlock_bh+0x1e/0x20 Jul 26 15:05:02 rx [11061396.054817] nf_conntrack_tcp_packet+0x29e/0xbe0 [nf_conntrack] Jul 26 15:05:02 rx [11061396.060994] ? get_l4proto+0xe7/0x190 [nf_conntrack] Jul 26 15:05:02 rx [11061396.066220] nf_conntrack_in+0xe9/0x670 [nf_conntrack] Jul 26 15:05:02 rx [11061396.071618] ipv6_conntrack_local+0x14/0x20 [nf_conntrack] Jul 26 15:05:02 rx [11061396.077356] nf_hook_slow+0x45/0xb0 Jul 26 15:05:02 rx [11061396.081098] ip6_xmit+0x3f0/0x5d0 Jul 26 15:05:02 rx [11061396.084670] ? ipv6_anycast_cleanup+0x50/0x50 Jul 26 15:05:02 rx [11061396.089282] ? __sk_dst_check+0x38/0x70 Jul 26 15:05:02 rx [11061396.093381] ? inet6_csk_route_socket+0x13b/0x200 Jul 26 15:05:02 rx [11061396.098346] inet6_csk_xmit+0xa7/0xf0 Jul 26 15:05:02 rx [11061396.102263] __tcp_transmit_skb+0x550/0xb30 Jul 26 15:05:02 rx [11061396.106701] tcp_write_xmit+0x3c6/0xc20 Jul 26 15:05:02 rx [11061396.110792] ? __alloc_skb+0x98/0x1d0 Jul 26 15:05:02 rx [11061396.114708] __tcp_push_pending_frames+0x37/0x100 Jul 26 15:05:02 rx [11061396.119667] tcp_push+0xfd/0x100 Jul 26 15:05:02 rx [11061396.123150] tcp_sendmsg_locked+0xc70/0xdd0 Jul 26 15:05:02 rx [11061396.127588] tcp_sendmsg+0x2d/0x50 Jul 26 15:05:02 rx [11061396.131245] inet6_sendmsg+0x43/0x70 Jul 26 15:05:02 rx [11061396.135075] __sock_sendmsg+0x48/0x70 Jul 26 15:05:02 rx [11061396.138994] ____sys_sendmsg+0x212/0x280 Jul 26 15:05:02 rx [11061396.143172] ___sys_sendmsg+0x88/0xd0 Jul 26 15:05:02 rx [11061396.147098] ? __seccomp_filter+0x7e/0x6b0 Jul 26 15:05:02 rx [11061396.151446] ? __switch_to+0x39c/0x460 Jul 26 15:05:02 rx [11061396.155453] ? __switch_to_asm+0x42/0x80 Jul 26 15:05:02 rx [11061396.159636] ? __switch_to_asm+0x5a/0x80 Jul 26 15:05:02 rx [11061396.163816] __sys_sendmsg+0x5c/0xa0 Jul 26 15:05:02 rx [11061396.167647] __x64_sys_sendmsg+0x1f/0x30 Jul 26 15:05:02 rx [11061396.171832] do_syscall_64+0x57/0x190 Jul 26 15:05:02 rx [11061396.175748] entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Jul 26 15:05:02 rx [11061396.181055] RIP: 0033:0x7f1ef692618d Jul 26 15:05:02 rx [11061396.184893] Code: 28 89 54 24 1c 48 89 74 24 10 89 7c 24 08 e8 ca ee ff ff 8b 54 24 1c 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 2f 44 89 c7 48 89 44 24 08 e8 fe ee ff ff 48 Jul 26 15:05:02 rx [11061396.203889] RSP: 002b:00007f1ef4a26aa0 EFLAGS: 00000293 ORIG_RAX: 000000000000002e Jul 26 15:05:02 rx [11061396.211708] RAX: ffffffffffffffda RBX: 000000000000084b RCX: 00007f1ef692618d Jul 26 15:05:02 rx [11061396.219091] RDX: 0000000000004000 RSI: 00007f1ef4a26b10 RDI: 0000000000000275 Jul 26 15:05:02 rx [11061396.226475] RBP: 0000000000004000 R08: 0000000000000000 R09: 0000000000000020 Jul 26 15:05:02 rx [11061396.233859] R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000084b Jul 26 15:05:02 rx [11061396.241243] R13: 00007f1ef4a26b10 R14: 0000000000000275 R15: 000055592030f1e8 Jul 26 15:05:02 rx [11061396.248628] Modules linked in: vrf bridge stp llc vxlan ip6_udp_tunnel udp_tunnel nls_iso8859_1 amd64_edac_mod edac_mce_amd kvm_amd kvm crct10dif_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper wmi_bmof ipmi_ssif input_leds joydev rndis_host cdc_ether usbnet mii ast drm_vram_helper ttm drm_kms_helper i2c_algo_bit fb_sys_fops syscopyarea sysfillrect sysimgblt ccp mac_hid ipmi_si ipmi_devintf ipmi_msghandler nft_ct sch_fq_codel nf_tables_set nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink ramoops reed_solomon efi_pstore drm ip_tables x_tables autofs4 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid0 multipath linear mlx5_ib ib_uverbs ib_core raid1 mlx5_core hid_generic pci_hyperv_intf crc32_pclmul tls usbhid ahci mlxfw bnxt_en libahci hid nvme i2c_piix4 nvme_core wmi Jul 26 15:05:02 rx [11061396.324334] CR2: 0000000000000020 Jul 26 15:05:02 rx [11061396.327944] ---[ end trace 68a2b679d1cfb4f1 ]--- Jul 26 15:05:02 rx [11061396.433435] RIP: 0010:tcp_rearm_rto+0xe4/0x160 Jul 26 15:05:02 rx [11061396.438137] Code: 87 ca 04 00 00 00 5b 41 5c 41 5d 5d c3 c3 49 8b bc 24 40 06 00 00 eb 8d 48 bb cf f7 53 e3 a5 9b c4 20 4c 89 ef e8 0c fe 0e 00 <48> 8b 78 20 48 c1 ef 03 48 89 f8 41 8b bc 24 80 04 00 00 48 f7 e3 Jul 26 15:05:02 rx [11061396.457144] RSP: 0018:ffffb75d40003e08 EFLAGS: 00010246 Jul 26 15:05:02 rx [11061396.462629] RAX: 0000000000000000 RBX: 20c49ba5e353f7cf RCX: 0000000000000000 Jul 26 15:05:02 rx [11061396.470012] RDX: 0000000062177c30 RSI: 000000000000231c RDI: ffff9874ad283a60 Jul 26 15:05:02 rx [11061396.477396] RBP: ffffb75d40003e20 R08: 0000000000000000 R09: ffff987605e20aa8 Jul 26 15:05:02 rx [11061396.484779] R10: ffffb75d40003f00 R11: ffffb75d4460f740 R12: ffff9874ad283900 Jul 26 15:05:02 rx [11061396.492164] R13: ffff9874ad283a60 R14: ffff9874ad283980 R15: ffff9874ad283d30 Jul 26 15:05:02 rx [11061396.499547] FS: 00007f1ef4a2e700(0000) GS:ffff987605e00000(0000) knlGS:0000000000000000 Jul 26 15:05:02 rx [11061396.507886] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jul 26 15:05:02 rx [11061396.513884] CR2: 0000000000000020 CR3: 0000003e450ba003 CR4: 0000000000760ef0 Jul 26 15:05:02 rx [11061396.521267] PKRU: 55555554 Jul 26 15:05:02 rx [11061396.524230] Kernel panic - not syncing: Fatal exception in interrupt Jul 26 15:05:02 rx [11061396.530885] Kernel Offset: 0x1b200000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) Jul 26 15:05:03 rx [11061396.660181] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- After we hit this we disabled TLP by setting tcp_early_retrans to 0 and then hit the crash in the RACK case: Aug 7 07:26:16 rx [1006006.265582] BUG: kernel NULL pointer dereference, address: 0000000000000020 Aug 7 07:26:16 rx [1006006.272719] #PF: supervisor read access in kernel mode Aug 7 07:26:16 rx [1006006.278030] #PF: error_code(0x0000) - not-present page Aug 7 07:26:16 rx [1006006.283343] PGD 0 P4D 0 Aug 7 07:26:16 rx [1006006.286057] Oops: 0000 [#1] SMP NOPTI Aug 7 07:26:16 rx [1006006.289896] CPU: 5 PID: 0 Comm: swapper/5 Tainted: G W 5.4.0-174-generic #193-Ubuntu Aug 7 07:26:16 rx [1006006.299107] Hardware name: Supermicro SMC 2x26 os-gen8 64C NVME-Y 256G/H12SSW-NTR, BIOS 2.5.V1.2U.NVMe.UEFI 05/09/2023 Aug 7 07:26:16 rx [1006006.309970] RIP: 0010:tcp_rearm_rto+0xe4/0x160 Aug 7 07:26:16 rx [1006006.314584] Code: 87 ca 04 00 00 00 5b 41 5c 41 5d 5d c3 c3 49 8b bc 24 40 06 00 00 eb 8d 48 bb cf f7 53 e3 a5 9b c4 20 4c 89 ef e8 0c fe 0e 00 <48> 8b 78 20 48 c1 ef 03 48 89 f8 41 8b bc 24 80 04 00 00 48 f7 e3 Aug 7 07:26:16 rx [1006006.333499] RSP: 0018:ffffb42600a50960 EFLAGS: 00010246 Aug 7 07:26:16 rx [1006006.338895] RAX: 0000000000000000 RBX: 20c49ba5e353f7cf RCX: 0000000000000000 Aug 7 07:26:16 rx [1006006.346193] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff92d687ed8160 Aug 7 07:26:16 rx [1006006.353489] RBP: ffffb42600a50978 R08: 0000000000000000 R09: 00000000cd896dcc Aug 7 07:26:16 rx [1006006.360786] R10: ffff92dc3404f400 R11: 0000000000000001 R12: ffff92d687ed8000 Aug 7 07:26:16 rx [1006006.368084] R13: ffff92d687ed8160 R14: 00000000cd896dcc R15: 00000000cd8fca81 Aug 7 07:26:16 rx [1006006.375381] FS: 0000000000000000(0000) GS:ffff93158ad40000(0000) knlGS:0000000000000000 Aug 7 07:26:16 rx [1006006.383632] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Aug 7 07:26:16 rx [1006006.389544] CR2: 0000000000000020 CR3: 0000003e775ce006 CR4: 0000000000760ee0 Aug 7 07:26:16 rx [1006006.396839] PKRU: 55555554 Aug 7 07:26:16 rx [1006006.399717] Call Trace: Aug 7 07:26:16 rx [1006006.402335] Aug 7 07:26:16 rx [1006006.404525] ? show_regs.cold+0x1a/0x1f Aug 7 07:26:16 rx [1006006.408532] ? __die+0x90/0xd9 Aug 7 07:26:16 rx [1006006.411760] ? no_context+0x196/0x380 Aug 7 07:26:16 rx [1006006.415599] ? __bad_area_nosemaphore+0x50/0x1a0 Aug 7 07:26:16 rx [1006006.420392] ? _raw_spin_lock+0x1e/0x30 Aug 7 07:26:16 rx [1006006.424401] ? bad_area_nosemaphore+0x16/0x20 Aug 7 07:26:16 rx [1006006.428927] ? do_user_addr_fault+0x267/0x450 Aug 7 07:26:16 rx [1006006.433450] ? __do_page_fault+0x58/0x90 Aug 7 07:26:16 rx [1006006.437542] ? do_page_fault+0x2c/0xe0 Aug 7 07:26:16 rx [1006006.441470] ? page_fault+0x34/0x40 Aug 7 07:26:16 rx [1006006.445134] ? tcp_rearm_rto+0xe4/0x160 Aug 7 07:26:16 rx [1006006.449145] tcp_ack+0xa32/0xb30 Aug 7 07:26:16 rx [1006006.452542] tcp_rcv_established+0x13c/0x670 Aug 7 07:26:16 rx [1006006.456981] ? sk_filter_trim_cap+0x48/0x220 Aug 7 07:26:16 rx [1006006.461419] tcp_v6_do_rcv+0xdb/0x450 Aug 7 07:26:16 rx [1006006.465257] tcp_v6_rcv+0xc2b/0xd10 Aug 7 07:26:16 rx [1006006.468918] ip6_protocol_deliver_rcu+0xd3/0x4e0 Aug 7 07:26:16 rx [1006006.473706] ip6_input_finish+0x15/0x20 Aug 7 07:26:16 rx [1006006.477710] ip6_input+0xa2/0xb0 Aug 7 07:26:16 rx [1006006.481109] ? ip6_protocol_deliver_rcu+0x4e0/0x4e0 Aug 7 07:26:16 rx [1006006.486151] ip6_sublist_rcv_finish+0x3d/0x50 Aug 7 07:26:16 rx [1006006.490679] ip6_sublist_rcv+0x1aa/0x250 Aug 7 07:26:16 rx [1006006.494779] ? ip6_rcv_finish_core.isra.0+0xa0/0xa0 Aug 7 07:26:16 rx [1006006.499828] ipv6_list_rcv+0x112/0x140 Aug 7 07:26:16 rx [1006006.503748] __netif_receive_skb_list_core+0x1a4/0x250 Aug 7 07:26:16 rx [1006006.509057] netif_receive_skb_list_internal+0x1a1/0x2b0 Aug 7 07:26:16 rx [1006006.514538] gro_normal_list.part.0+0x1e/0x40 Aug 7 07:26:16 rx [1006006.519068] napi_complete_done+0x91/0x130 Aug 7 07:26:16 rx [1006006.523352] mlx5e_napi_poll+0x18e/0x610 [mlx5_core] Aug 7 07:26:16 rx [1006006.528481] net_rx_action+0x142/0x390 Aug 7 07:26:16 rx [1006006.532398] __do_softirq+0xd1/0x2c1 Aug 7 07:26:16 rx [1006006.536142] irq_exit+0xae/0xb0 Aug 7 07:26:16 rx [1006006.539452] do_IRQ+0x5a/0xf0 Aug 7 07:26:16 rx [1006006.542590] common_interrupt+0xf/0xf Aug 7 07:26:16 rx [1006006.546421] Aug 7 07:26:16 rx [1006006.548695] RIP: 0010:native_safe_halt+0xe/0x10 Aug 7 07:26:16 rx [1006006.553399] Code: 7b ff ff ff eb bd 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 36 2c 50 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 26 2c 50 00 fb f4 90 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 e8 dd 5e 61 ff 65 Aug 7 07:26:16 rx [1006006.572309] RSP: 0018:ffffb42600177e70 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffc2 Aug 7 07:26:16 rx [1006006.580040] RAX: ffffffff8ed08b20 RBX: 0000000000000005 RCX: 0000000000000001 Aug 7 07:26:16 rx [1006006.587337] RDX: 00000000f48eeca2 RSI: 0000000000000082 RDI: 0000000000000082 Aug 7 07:26:16 rx [1006006.594635] RBP: ffffb42600177e90 R08: 0000000000000000 R09: 000000000000020f Aug 7 07:26:16 rx [1006006.601931] R10: 0000000000100000 R11: 0000000000000000 R12: 0000000000000005 Aug 7 07:26:16 rx [1006006.609229] R13: ffff93157deb5f00 R14: 0000000000000000 R15: 0000000000000000 Aug 7 07:26:16 rx [1006006.616530] ? __cpuidle_text_start+0x8/0x8 Aug 7 07:26:16 rx [1006006.620886] ? default_idle+0x20/0x140 Aug 7 07:26:16 rx [1006006.624804] arch_cpu_idle+0x15/0x20 Aug 7 07:26:16 rx [1006006.628545] default_idle_call+0x23/0x30 Aug 7 07:26:16 rx [1006006.632640] do_idle+0x1fb/0x270 Aug 7 07:26:16 rx [1006006.636035] cpu_startup_entry+0x20/0x30 Aug 7 07:26:16 rx [1006006.640126] start_secondary+0x178/0x1d0 Aug 7 07:26:16 rx [1006006.644218] secondary_startup_64+0xa4/0xb0 Aug 7 07:26:17 rx [1006006.648568] Modules linked in: vrf bridge stp llc vxlan ip6_udp_tunnel udp_tunnel nls_iso8859_1 nft_ct amd64_edac_mod edac_mce_amd kvm_amd kvm crct10dif_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper wmi_bmof ipmi_ssif input_leds joydev rndis_host cdc_ether usbnet ast mii drm_vram_helper ttm drm_kms_helper i2c_algo_bit fb_sys_fops syscopyarea sysfillrect sysimgblt ccp mac_hid ipmi_si ipmi_devintf ipmi_msghandler sch_fq_codel nf_tables_set nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink ramoops reed_solomon efi_pstore drm ip_tables x_tables autofs4 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid0 multipath linear mlx5_ib ib_uverbs ib_core raid1 hid_generic mlx5_core pci_hyperv_intf crc32_pclmul usbhid ahci tls mlxfw bnxt_en hid libahci nvme i2c_piix4 nvme_core wmi [last unloaded: cpuid] Aug 7 07:26:17 rx [1006006.726180] CR2: 0000000000000020 Aug 7 07:26:17 rx [1006006.729718] ---[ end trace e0e2e37e4e612984 ]--- Prior to seeing the first crash and on other machines we also see the warning in tcp_send_loss_probe() where packets_out is non-zero, but both transmit and retrans queues are empty so we know the box is seeing some accounting issue in this area: Jul 26 09:15:27 kernel: ------------[ cut here ]------------ Jul 26 09:15:27 kernel: invalid inflight: 2 state 1 cwnd 68 mss 8988 Jul 26 09:15:27 kernel: WARNING: CPU: 16 PID: 0 at net/ipv4/tcp_output.c:2605 tcp_send_loss_probe+0x214/0x220 Jul 26 09:15:27 kernel: Modules linked in: vrf bridge stp llc vxlan ip6_udp_tunnel udp_tunnel nls_iso8859_1 nft_ct amd64_edac_mod edac_mce_amd kvm_amd kvm crct10dif_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper wmi_bmof ipmi_ssif joydev input_leds rndis_host cdc_ether usbnet mii ast drm_vram_helper ttm drm_kms_he> Jul 26 09:15:27 kernel: CPU: 16 PID: 0 Comm: swapper/16 Not tainted 5.4.0-174-generic #193-Ubuntu Jul 26 09:15:27 kernel: Hardware name: Supermicro SMC 2x26 os-gen8 64C NVME-Y 256G/H12SSW-NTR, BIOS 2.5.V1.2U.NVMe.UEFI 05/09/2023 Jul 26 09:15:27 kernel: RIP: 0010:tcp_send_loss_probe+0x214/0x220 Jul 26 09:15:27 kernel: Code: 08 26 01 00 75 e2 41 0f b6 54 24 12 41 8b 8c 24 c0 06 00 00 45 89 f0 48 c7 c7 e0 b4 20 a7 c6 05 8d 08 26 01 01 e8 4a c0 0f 00 <0f> 0b eb ba 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 Jul 26 09:15:27 kernel: RSP: 0018:ffffb7838088ce00 EFLAGS: 00010286 Jul 26 09:15:27 kernel: RAX: 0000000000000000 RBX: ffff9b84b5630430 RCX: 0000000000000006 Jul 26 09:15:27 kernel: RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff9b8e4621c8c0 Jul 26 09:15:27 kernel: RBP: ffffb7838088ce18 R08: 0000000000000927 R09: 0000000000000004 Jul 26 09:15:27 kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff9b84b5630000 Jul 26 09:15:27 kernel: R13: 0000000000000000 R14: 000000000000231c R15: ffff9b84b5630430 Jul 26 09:15:27 kernel: FS: 0000000000000000(0000) GS:ffff9b8e46200000(0000) knlGS:0000000000000000 Jul 26 09:15:27 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jul 26 09:15:27 kernel: CR2: 000056238cec2380 CR3: 0000003e49ede005 CR4: 0000000000760ee0 Jul 26 09:15:27 kernel: PKRU: 55555554 Jul 26 09:15:27 kernel: Call Trace: Jul 26 09:15:27 kernel: <IRQ> Jul 26 09:15:27 kernel: ? show_regs.cold+0x1a/0x1f Jul 26 09:15:27 kernel: ? __warn+0x98/0xe0 Jul 26 09:15:27 kernel: ? tcp_send_loss_probe+0x214/0x220 Jul 26 09:15:27 kernel: ? report_bug+0xd1/0x100 Jul 26 09:15:27 kernel: ? do_error_trap+0x9b/0xc0 Jul 26 09:15:27 kernel: ? do_invalid_op+0x3c/0x50 Jul 26 09:15:27 kernel: ? tcp_send_loss_probe+0x214/0x220 Jul 26 09:15:27 kernel: ? invalid_op+0x1e/0x30 Jul 26 09:15:27 kernel: ? tcp_send_loss_probe+0x214/0x220 Jul 26 09:15:27 kernel: tcp_write_timer_handler+0x1b4/0x240 Jul 26 09:15:27 kernel: tcp_write_timer+0x9e/0xe0 Jul 26 09:15:27 kernel: ? tcp_write_timer_handler+0x240/0x240 Jul 26 09:15:27 kernel: call_timer_fn+0x32/0x130 Jul 26 09:15:27 kernel: __run_timers.part.0+0x180/0x280 Jul 26 09:15:27 kernel: ? timerqueue_add+0x9b/0xb0 Jul 26 09:15:27 kernel: ? enqueue_hrtimer+0x3d/0x90 Jul 26 09:15:27 kernel: ? do_error_trap+0x9b/0xc0 Jul 26 09:15:27 kernel: ? do_invalid_op+0x3c/0x50 Jul 26 09:15:27 kernel: ? tcp_send_loss_probe+0x214/0x220 Jul 26 09:15:27 kernel: ? invalid_op+0x1e/0x30 Jul 26 09:15:27 kernel: ? tcp_send_loss_probe+0x214/0x220 Jul 26 09:15:27 kernel: tcp_write_timer_handler+0x1b4/0x240 Jul 26 09:15:27 kernel: tcp_write_timer+0x9e/0xe0 Jul 26 09:15:27 kernel: ? tcp_write_timer_handler+0x240/0x240 Jul 26 09:15:27 kernel: call_timer_fn+0x32/0x130 Jul 26 09:15:27 kernel: __run_timers.part.0+0x180/0x280 Jul 26 09:15:27 kernel: ? timerqueue_add+0x9b/0xb0 Jul 26 09:15:27 kernel: ? enqueue_hrtimer+0x3d/0x90 Jul 26 09:15:27 kernel: ? recalibrate_cpu_khz+0x10/0x10 Jul 26 09:15:27 kernel: ? ktime_get+0x3e/0xa0 Jul 26 09:15:27 kernel: ? native_x2apic_icr_write+0x30/0x30 Jul 26 09:15:27 kernel: run_timer_softirq+0x2a/0x50 Jul 26 09:15:27 kernel: __do_softirq+0xd1/0x2c1 Jul 26 09:15:27 kernel: irq_exit+0xae/0xb0 Jul 26 09:15:27 kernel: smp_apic_timer_interrupt+0x7b/0x140 Jul 26 09:15:27 kernel: apic_timer_interrupt+0xf/0x20 Jul 26 09:15:27 kernel: </IRQ> Jul 26 09:15:27 kernel: RIP: 0010:native_safe_halt+0xe/0x10 Jul 26 09:15:27 kernel: Code: 7b ff ff ff eb bd 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 36 2c 50 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 26 2c 50 00 fb f4 <c3> 90 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 e8 dd 5e 61 ff 65 Jul 26 09:15:27 kernel: RSP: 0018:ffffb783801cfe70 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 Jul 26 09:15:27 kernel: RAX: ffffffffa6908b20 RBX: 0000000000000010 RCX: 0000000000000001 Jul 26 09:15:27 kernel: RDX: 000000006fc0c97e RSI: 0000000000000082 RDI: 0000000000000082 Jul 26 09:15:27 kernel: RBP: ffffb783801cfe90 R08: 0000000000000000 R09: 0000000000000225 Jul 26 09:15:27 kernel: R10: 0000000000100000 R11: 0000000000000000 R12: 0000000000000010 Jul 26 09:15:27 kernel: R13: ffff9b8e390b0000 R14: 0000000000000000 R15: 0000000000000000 Jul 26 09:15:27 kernel: ? __cpuidle_text_start+0x8/0x8 Jul 26 09:15:27 kernel: ? default_idle+0x20/0x140 Jul 26 09:15:27 kernel: arch_cpu_idle+0x15/0x20 Jul 26 09:15:27 kernel: default_idle_call+0x23/0x30 Jul 26 09:15:27 kernel: do_idle+0x1fb/0x270 Jul 26 09:15:27 kernel: cpu_startup_entry+0x20/0x30 Jul 26 09:15:27 kernel: start_secondary+0x178/0x1d0 Jul 26 09:15:27 kernel: secondary_startup_64+0xa4/0xb0 Jul 26 09:15:27 kernel: ---[ end trace e7ac822987e33be1 ]--- The NULL ptr deref is coming from tcp_rto_delta_us() attempting to pull an skb off the head of the retransmit queue and then dereferencing that skb to get the skb_mstamp_ns value via tcp_skb_timestamp_us(skb). The crash is the same one that was reported a # of years ago here: https://lore.kernel.org/netdev/86c0f836-9a7c-438b-d81a-839be45f1f58@gmail.com/T/#t and the kernel we're running has the fix which was added to resolve this issue. Unfortunately we've been unsuccessful so far in reproducing this problem in the lab and do not have the luxury of pushing out a new kernel to try and test if newer kernels resolve this issue at the moment. I realize this is a report against both an Ubuntu kernel and also an older 5.4 kernel. I have reported this issue to Ubuntu here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2077657 however I feel like since this issue has possibly cropped up again it makes sense to build in some protection in this path (even on the latest kernel versions) since the code in question just blindly assumes there's a valid skb without testing if it's NULL b/f it looks at the timestamp. Given we have seen crashes in this path before and now this case it seems like we should protect ourselves for when packets_out accounting is incorrect. While we should fix that root cause we should also just make sure the skb is not NULL before dereferencing it. Also add a warn once here to capture some information if/when the problem case is hit again. Fixes: e1a10ef7fa87 ("tcp: introduce tcp_rto_delta_us() helper for xmit timer fix") Signed-off-by: Josh Hunt <johunt@akamai.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c8770db2d54437a5f49417ae7b46f7de23d14db6 ]

We have some machines running stock Ubuntu 20.04.6 which is their 5.4.0-174-generic
kernel that are running ceph and recently hit a null ptr dereference in
tcp_rearm_rto(). Initially hitting it from the TLP path, but then later we also
saw it getting hit from the RACK case as well. Here are examples of the oops
messages we saw in each of those cases:

Jul 26 15:05:02 rx [11061395.780353] BUG: kernel NULL pointer dereference, address: 0000000000000020
Jul 26 15:05:02 rx [11061395.787572] #PF: supervisor read access in kernel mode
Jul 26 15:05:02 rx [11061395.792971] #PF: error_code(0x0000) - not-present page
Jul 26 15:05:02 rx [11061395.798362] PGD 0 P4D 0
Jul 26 15:05:02 rx [11061395.801164] Oops: 0000 [#1] SMP NOPTI
Jul 26 15:05:02 rx [11061395.805091] CPU: 0 PID: 9180 Comm: msgr-worker-1 Tainted: G W 5.4.0-174-generic #193-Ubuntu
Jul 26 15:05:02 rx [11061395.814996] Hardware name: Supermicro SMC 2x26 os-gen8 64C NVME-Y 256G/H12SSW-NTR, BIOS 2.5.V1.2U.NVMe.UEFI 05/09/2023
Jul 26 15:05:02 rx [11061395.825952] RIP: 0010:tcp_rearm_rto+0xe4/0x160
Jul 26 15:05:02 rx [11061395.830656] Code: 87 ca 04 00 00 00 5b 41 5c 41 5d 5d c3 c3 49 8b bc 24 40 06 00 00 eb 8d 48 bb cf f7 53 e3 a5 9b c4 20 4c 89 ef e8 0c fe 0e 00 <48> 8b 78 20 48 c1 ef 03 48 89 f8 41 8b bc 24 80 04 00 00 48 f7 e3
Jul 26 15:05:02 rx [11061395.849665] RSP: 0018:ffffb75d40003e08 EFLAGS: 00010246
Jul 26 15:05:02 rx [11061395.855149] RAX: 0000000000000000 RBX: 20c49ba5e353f7cf RCX: 0000000000000000
Jul 26 15:05:02 rx [11061395.862542] RDX: 0000000062177c30 RSI: 000000000000231c RDI: ffff9874ad283a60
Jul 26 15:05:02 rx [11061395.869933] RBP: ffffb75d40003e20 R08: 0000000000000000 R09: ffff987605e20aa8
Jul 26 15:05:02 rx [11061395.877318] R10: ffffb75d40003f00 R11: ffffb75d4460f740 R12: ffff9874ad283900
Jul 26 15:05:02 rx [11061395.884710] R13: ffff9874ad283a60 R14: ffff9874ad283980 R15: ffff9874ad283d30
Jul 26 15:05:02 rx [11061395.892095] FS: 00007f1ef4a2e700(0000) GS:ffff987605e00000(0000) knlGS:0000000000000000
Jul 26 15:05:02 rx [11061395.900438] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jul 26 15:05:02 rx [11061395.906435] CR2: 0000000000000020 CR3: 0000003e450ba003 CR4: 0000000000760ef0
Jul 26 15:05:02 rx [11061395.913822] PKRU: 55555554
Jul 26 15:05:02 rx [11061395.916786] Call Trace:
Jul 26 15:05:02 rx [11061395.919488]
Jul 26 15:05:02 rx [11061395.921765] ? show_regs.cold+0x1a/0x1f
Jul 26 15:05:02 rx [11061395.925859] ? __die+0x90/0xd9
Jul 26 15:05:02 rx [11061395.929169] ? no_context+0x196/0x380
Jul 26 15:05:02 rx [11061395.933088] ? ip6_protocol_deliver_rcu+0x4e0/0x4e0
Jul 26 15:05:02 rx [11061395.938216] ? ip6_sublist_rcv_finish+0x3d/0x50
Jul 26 15:05:02 rx [11061395.943000] ? __bad_area_nosemaphore+0x50/0x1a0
Jul 26 15:05:02 rx [11061395.947873] ? bad_area_nosemaphore+0x16/0x20
Jul 26 15:05:02 rx [11061395.952486] ? do_user_addr_fault+0x267/0x450
Jul 26 15:05:02 rx [11061395.957104] ? ipv6_list_rcv+0x112/0x140
Jul 26 15:05:02 rx [11061395.961279] ? __do_page_fault+0x58/0x90
Jul 26 15:05:02 rx [11061395.965458] ? do_page_fault+0x2c/0xe0
Jul 26 15:05:02 rx [11061395.969465] ? page_fault+0x34/0x40
Jul 26 15:05:02 rx [11061395.973217] ? tcp_rearm_rto+0xe4/0x160
Jul 26 15:05:02 rx [11061395.977313] ? tcp_rearm_rto+0xe4/0x160
Jul 26 15:05:02 rx [11061395.981408] tcp_send_loss_probe+0x10b/0x220
Jul 26 15:05:02 rx [11061395.985937] tcp_write_timer_handler+0x1b4/0x240
Jul 26 15:05:02 rx [11061395.990809] tcp_write_timer+0x9e/0xe0
Jul 26 15:05:02 rx [11061395.994814] ? tcp_write_timer_handler+0x240/0x240
Jul 26 15:05:02 rx [11061395.999866] call_timer_fn+0x32/0x130
Jul 26 15:05:02 rx [11061396.003782] __run_timers.part.0+0x180/0x280
Jul 26 15:05:02 rx [11061396.008309] ? recalibrate_cpu_khz+0x10/0x10
Jul 26 15:05:02 rx [11061396.012841] ? native_x2apic_icr_write+0x30/0x30
Jul 26 15:05:02 rx [11061396.017718] ? lapic_next_event+0x21/0x30
Jul 26 15:05:02 rx [11061396.021984] ? clockevents_program_event+0x8f/0xe0
Jul 26 15:05:02 rx [11061396.027035] run_timer_softirq+0x2a/0x50
Jul 26 15:05:02 rx [11061396.031212] __do_softirq+0xd1/0x2c1
Jul 26 15:05:02 rx [11061396.035044] do_softirq_own_stack+0x2a/0x40
Jul 26 15:05:02 rx [11061396.039480]
Jul 26 15:05:02 rx [11061396.041840] do_softirq.part.0+0x46/0x50
Jul 26 15:05:02 rx [11061396.046022] __local_bh_enable_ip+0x50/0x60
Jul 26 15:05:02 rx [11061396.050460] _raw_spin_unlock_bh+0x1e/0x20
Jul 26 15:05:02 rx [11061396.054817] nf_conntrack_tcp_packet+0x29e/0xbe0 [nf_conntrack]
Jul 26 15:05:02 rx [11061396.060994] ? get_l4proto+0xe7/0x190 [nf_conntrack]
Jul 26 15:05:02 rx [11061396.066220] nf_conntrack_in+0xe9/0x670 [nf_conntrack]
Jul 26 15:05:02 rx [11061396.071618] ipv6_conntrack_local+0x14/0x20 [nf_conntrack]
Jul 26 15:05:02 rx [11061396.077356] nf_hook_slow+0x45/0xb0
Jul 26 15:05:02 rx [11061396.081098] ip6_xmit+0x3f0/0x5d0
Jul 26 15:05:02 rx [11061396.084670] ? ipv6_anycast_cleanup+0x50/0x50
Jul 26 15:05:02 rx [11061396.089282] ? __sk_dst_check+0x38/0x70
Jul 26 15:05:02 rx [11061396.093381] ? inet6_csk_route_socket+0x13b/0x200
Jul 26 15:05:02 rx [11061396.098346] inet6_csk_xmit+0xa7/0xf0
Jul 26 15:05:02 rx [11061396.102263] __tcp_transmit_skb+0x550/0xb30
Jul 26 15:05:02 rx [11061396.106701] tcp_write_xmit+0x3c6/0xc20
Jul 26 15:05:02 rx [11061396.110792] ? __alloc_skb+0x98/0x1d0
Jul 26 15:05:02 rx [11061396.114708] __tcp_push_pending_frames+0x37/0x100
Jul 26 15:05:02 rx [11061396.119667] tcp_push+0xfd/0x100
Jul 26 15:05:02 rx [11061396.123150] tcp_sendmsg_locked+0xc70/0xdd0
Jul 26 15:05:02 rx [11061396.127588] tcp_sendmsg+0x2d/0x50
Jul 26 15:05:02 rx [11061396.131245] inet6_sendmsg+0x43/0x70
Jul 26 15:05:02 rx [11061396.135075] __sock_sendmsg+0x48/0x70
Jul 26 15:05:02 rx [11061396.138994] ____sys_sendmsg+0x212/0x280
Jul 26 15:05:02 rx [11061396.143172] ___sys_sendmsg+0x88/0xd0
Jul 26 15:05:02 rx [11061396.147098] ? __seccomp_filter+0x7e/0x6b0
Jul 26 15:05:02 rx [11061396.151446] ? __switch_to+0x39c/0x460
Jul 26 15:05:02 rx [11061396.155453] ? __switch_to_asm+0x42/0x80
Jul 26 15:05:02 rx [11061396.159636] ? __switch_to_asm+0x5a/0x80
Jul 26 15:05:02 rx [11061396.163816] __sys_sendmsg+0x5c/0xa0
Jul 26 15:05:02 rx [11061396.167647] __x64_sys_sendmsg+0x1f/0x30
Jul 26 15:05:02 rx [11061396.171832] do_syscall_64+0x57/0x190
Jul 26 15:05:02 rx [11061396.175748] entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Jul 26 15:05:02 rx [11061396.181055] RIP: 0033:0x7f1ef692618d
Jul 26 15:05:02 rx [11061396.184893] Code: 28 89 54 24 1c 48 89 74 24 10 89 7c 24 08 e8 ca ee ff ff 8b 54 24 1c 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 2f 44 89 c7 48 89 44 24 08 e8 fe ee ff ff 48
Jul 26 15:05:02 rx [11061396.203889] RSP: 002b:00007f1ef4a26aa0 EFLAGS: 00000293 ORIG_RAX: 000000000000002e
Jul 26 15:05:02 rx [11061396.211708] RAX: ffffffffffffffda RBX: 000000000000084b RCX: 00007f1ef692618d
Jul 26 15:05:02 rx [11061396.219091] RDX: 0000000000004000 RSI: 00007f1ef4a26b10 RDI: 0000000000000275
Jul 26 15:05:02 rx [11061396.226475] RBP: 0000000000004000 R08: 0000000000000000 R09: 0000000000000020
Jul 26 15:05:02 rx [11061396.233859] R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000084b
Jul 26 15:05:02 rx [11061396.241243] R13: 00007f1ef4a26b10 R14: 0000000000000275 R15: 000055592030f1e8
Jul 26 15:05:02 rx [11061396.248628] Modules linked in: vrf bridge stp llc vxlan ip6_udp_tunnel udp_tunnel nls_iso8859_1 amd64_edac_mod edac_mce_amd kvm_amd kvm crct10dif_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper wmi_bmof ipmi_ssif input_leds joydev rndis_host cdc_ether usbnet mii ast drm_vram_helper ttm drm_kms_helper i2c_algo_bit fb_sys_fops syscopyarea sysfillrect sysimgblt ccp mac_hid ipmi_si ipmi_devintf ipmi_msghandler nft_ct sch_fq_codel nf_tables_set nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink ramoops reed_solomon efi_pstore drm ip_tables x_tables autofs4 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid0 multipath linear mlx5_ib ib_uverbs ib_core raid1 mlx5_core hid_generic pci_hyperv_intf crc32_pclmul tls usbhid ahci mlxfw bnxt_en libahci hid nvme i2c_piix4 nvme_core wmi
Jul 26 15:05:02 rx [11061396.324334] CR2: 0000000000000020
Jul 26 15:05:02 rx [11061396.327944] ---[ end trace 68a2b679d1cfb4f1 ]---
Jul 26 15:05:02 rx [11061396.433435] RIP: 0010:tcp_rearm_rto+0xe4/0x160
Jul 26 15:05:02 rx [11061396.438137] Code: 87 ca 04 00 00 00 5b 41 5c 41 5d 5d c3 c3 49 8b bc 24 40 06 00 00 eb 8d 48 bb cf f7 53 e3 a5 9b c4 20 4c 89 ef e8 0c fe 0e 00 <48> 8b 78 20 48 c1 ef 03 48 89 f8 41 8b bc 24 80 04 00 00 48 f7 e3
Jul 26 15:05:02 rx [11061396.457144] RSP: 0018:ffffb75d40003e08 EFLAGS: 00010246
Jul 26 15:05:02 rx [11061396.462629] RAX: 0000000000000000 RBX: 20c49ba5e353f7cf RCX: 0000000000000000
Jul 26 15:05:02 rx [11061396.470012] RDX: 0000000062177c30 RSI: 000000000000231c RDI: ffff9874ad283a60
Jul 26 15:05:02 rx [11061396.477396] RBP: ffffb75d40003e20 R08: 0000000000000000 R09: ffff987605e20aa8
Jul 26 15:05:02 rx [11061396.484779] R10: ffffb75d40003f00 R11: ffffb75d4460f740 R12: ffff9874ad283900
Jul 26 15:05:02 rx [11061396.492164] R13: ffff9874ad283a60 R14: ffff9874ad283980 R15: ffff9874ad283d30
Jul 26 15:05:02 rx [11061396.499547] FS: 00007f1ef4a2e700(0000) GS:ffff987605e00000(0000) knlGS:0000000000000000
Jul 26 15:05:02 rx [11061396.507886] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jul 26 15:05:02 rx [11061396.513884] CR2: 0000000000000020 CR3: 0000003e450ba003 CR4: 0000000000760ef0
Jul 26 15:05:02 rx [11061396.521267] PKRU: 55555554
Jul 26 15:05:02 rx [11061396.524230] Kernel panic - not syncing: Fatal exception in interrupt
Jul 26 15:05:02 rx [11061396.530885] Kernel Offset: 0x1b200000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
Jul 26 15:05:03 rx [11061396.660181] ---[ end Kernel panic - not syncing: Fatal
 exception in interrupt ]---

After we hit this we disabled TLP by setting tcp_early_retrans to 0 and then hit the crash in the RACK case:

Aug 7 07:26:16 rx [1006006.265582] BUG: kernel NULL pointer dereference, address: 0000000000000020
Aug 7 07:26:16 rx [1006006.272719] #PF: supervisor read access in kernel mode
Aug 7 07:26:16 rx [1006006.278030] #PF: error_code(0x0000) - not-present page
Aug 7 07:26:16 rx [1006006.283343] PGD 0 P4D 0
Aug 7 07:26:16 rx [1006006.286057] Oops: 0000 [#1] SMP NOPTI
Aug 7 07:26:16 rx [1006006.289896] CPU: 5 PID: 0 Comm: swapper/5 Tainted: G W 5.4.0-174-generic #193-Ubuntu
Aug 7 07:26:16 rx [1006006.299107] Hardware name: Supermicro SMC 2x26 os-gen8 64C NVME-Y 256G/H12SSW-NTR, BIOS 2.5.V1.2U.NVMe.UEFI 05/09/2023
Aug 7 07:26:16 rx [1006006.309970] RIP: 0010:tcp_rearm_rto+0xe4/0x160
Aug 7 07:26:16 rx [1006006.314584] Code: 87 ca 04 00 00 00 5b 41 5c 41 5d 5d c3 c3 49 8b bc 24 40 06 00 00 eb 8d 48 bb cf f7 53 e3 a5 9b c4 20 4c 89 ef e8 0c fe 0e 00 <48> 8b 78 20 48 c1 ef 03 48 89 f8 41 8b bc 24 80 04 00 00 48 f7 e3
Aug 7 07:26:16 rx [1006006.333499] RSP: 0018:ffffb42600a50960 EFLAGS: 00010246
Aug 7 07:26:16 rx [1006006.338895] RAX: 0000000000000000 RBX: 20c49ba5e353f7cf RCX: 0000000000000000
Aug 7 07:26:16 rx [1006006.346193] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff92d687ed8160
Aug 7 07:26:16 rx [1006006.353489] RBP: ffffb42600a50978 R08: 0000000000000000 R09: 00000000cd896dcc
Aug 7 07:26:16 rx [1006006.360786] R10: ffff92dc3404f400 R11: 0000000000000001 R12: ffff92d687ed8000
Aug 7 07:26:16 rx [1006006.368084] R13: ffff92d687ed8160 R14: 00000000cd896dcc R15: 00000000cd8fca81
Aug 7 07:26:16 rx [1006006.375381] FS: 0000000000000000(0000) GS:ffff93158ad40000(0000) knlGS:0000000000000000
Aug 7 07:26:16 rx [1006006.383632] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Aug 7 07:26:16 rx [1006006.389544] CR2: 0000000000000020 CR3: 0000003e775ce006 CR4: 0000000000760ee0
Aug 7 07:26:16 rx [1006006.396839] PKRU: 55555554
Aug 7 07:26:16 rx [1006006.399717] Call Trace:
Aug 7 07:26:16 rx [1006006.402335]
Aug 7 07:26:16 rx [1006006.404525] ? show_regs.cold+0x1a/0x1f
Aug 7 07:26:16 rx [1006006.408532] ? __die+0x90/0xd9
Aug 7 07:26:16 rx [1006006.411760] ? no_context+0x196/0x380
Aug 7 07:26:16 rx [1006006.415599] ? __bad_area_nosemaphore+0x50/0x1a0
Aug 7 07:26:16 rx [1006006.420392] ? _raw_spin_lock+0x1e/0x30
Aug 7 07:26:16 rx [1006006.424401] ? bad_area_nosemaphore+0x16/0x20
Aug 7 07:26:16 rx [1006006.428927] ? do_user_addr_fault+0x267/0x450
Aug 7 07:26:16 rx [1006006.433450] ? __do_page_fault+0x58/0x90
Aug 7 07:26:16 rx [1006006.437542] ? do_page_fault+0x2c/0xe0
Aug 7 07:26:16 rx [1006006.441470] ? page_fault+0x34/0x40
Aug 7 07:26:16 rx [1006006.445134] ? tcp_rearm_rto+0xe4/0x160
Aug 7 07:26:16 rx [1006006.449145] tcp_ack+0xa32/0xb30
Aug 7 07:26:16 rx [1006006.452542] tcp_rcv_established+0x13c/0x670
Aug 7 07:26:16 rx [1006006.456981] ? sk_filter_trim_cap+0x48/0x220
Aug 7 07:26:16 rx [1006006.461419] tcp_v6_do_rcv+0xdb/0x450
Aug 7 07:26:16 rx [1006006.465257] tcp_v6_rcv+0xc2b/0xd10
Aug 7 07:26:16 rx [1006006.468918] ip6_protocol_deliver_rcu+0xd3/0x4e0
Aug 7 07:26:16 rx [1006006.473706] ip6_input_finish+0x15/0x20
Aug 7 07:26:16 rx [1006006.477710] ip6_input+0xa2/0xb0
Aug 7 07:26:16 rx [1006006.481109] ? ip6_protocol_deliver_rcu+0x4e0/0x4e0
Aug 7 07:26:16 rx [1006006.486151] ip6_sublist_rcv_finish+0x3d/0x50
Aug 7 07:26:16 rx [1006006.490679] ip6_sublist_rcv+0x1aa/0x250
Aug 7 07:26:16 rx [1006006.494779] ? ip6_rcv_finish_core.isra.0+0xa0/0xa0
Aug 7 07:26:16 rx [1006006.499828] ipv6_list_rcv+0x112/0x140
Aug 7 07:26:16 rx [1006006.503748] __netif_receive_skb_list_core+0x1a4/0x250
Aug 7 07:26:16 rx [1006006.509057] netif_receive_skb_list_internal+0x1a1/0x2b0
Aug 7 07:26:16 rx [1006006.514538] gro_normal_list.part.0+0x1e/0x40
Aug 7 07:26:16 rx [1006006.519068] napi_complete_done+0x91/0x130
Aug 7 07:26:16 rx [1006006.523352] mlx5e_napi_poll+0x18e/0x610 [mlx5_core]
Aug 7 07:26:16 rx [1006006.528481] net_rx_action+0x142/0x390
Aug 7 07:26:16 rx [1006006.532398] __do_softirq+0xd1/0x2c1
Aug 7 07:26:16 rx [1006006.536142] irq_exit+0xae/0xb0
Aug 7 07:26:16 rx [1006006.539452] do_IRQ+0x5a/0xf0
Aug 7 07:26:16 rx [1006006.542590] common_interrupt+0xf/0xf
Aug 7 07:26:16 rx [1006006.546421]
Aug 7 07:26:16 rx [1006006.548695] RIP: 0010:native_safe_halt+0xe/0x10
Aug 7 07:26:16 rx [1006006.553399] Code: 7b ff ff ff eb bd 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 36 2c 50 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 26 2c 50 00 fb f4 90 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 e8 dd 5e 61 ff 65
Aug 7 07:26:16 rx [1006006.572309] RSP: 0018:ffffb42600177e70 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffc2
Aug 7 07:26:16 rx [1006006.580040] RAX: ffffffff8ed08b20 RBX: 0000000000000005 RCX: 0000000000000001
Aug 7 07:26:16 rx [1006006.587337] RDX: 00000000f48eeca2 RSI: 0000000000000082 RDI: 0000000000000082
Aug 7 07:26:16 rx [1006006.594635] RBP: ffffb42600177e90 R08: 0000000000000000 R09: 000000000000020f
Aug 7 07:26:16 rx [1006006.601931] R10: 0000000000100000 R11: 0000000000000000 R12: 0000000000000005
Aug 7 07:26:16 rx [1006006.609229] R13: ffff93157deb5f00 R14: 0000000000000000 R15: 0000000000000000
Aug 7 07:26:16 rx [1006006.616530] ? __cpuidle_text_start+0x8/0x8
Aug 7 07:26:16 rx [1006006.620886] ? default_idle+0x20/0x140
Aug 7 07:26:16 rx [1006006.624804] arch_cpu_idle+0x15/0x20
Aug 7 07:26:16 rx [1006006.628545] default_idle_call+0x23/0x30
Aug 7 07:26:16 rx [1006006.632640] do_idle+0x1fb/0x270
Aug 7 07:26:16 rx [1006006.636035] cpu_startup_entry+0x20/0x30
Aug 7 07:26:16 rx [1006006.640126] start_secondary+0x178/0x1d0
Aug 7 07:26:16 rx [1006006.644218] secondary_startup_64+0xa4/0xb0
Aug 7 07:26:17 rx [1006006.648568] Modules linked in: vrf bridge stp llc vxlan ip6_udp_tunnel udp_tunnel nls_iso8859_1 nft_ct amd64_edac_mod edac_mce_amd kvm_amd kvm crct10dif_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper wmi_bmof ipmi_ssif input_leds joydev rndis_host cdc_ether usbnet ast mii drm_vram_helper ttm drm_kms_helper i2c_algo_bit fb_sys_fops syscopyarea sysfillrect sysimgblt ccp mac_hid ipmi_si ipmi_devintf ipmi_msghandler sch_fq_codel nf_tables_set nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink ramoops reed_solomon efi_pstore drm ip_tables x_tables autofs4 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid0 multipath linear mlx5_ib ib_uverbs ib_core raid1 hid_generic mlx5_core pci_hyperv_intf crc32_pclmul usbhid ahci tls mlxfw bnxt_en hid libahci nvme i2c_piix4 nvme_core wmi [last unloaded: cpuid]
Aug 7 07:26:17 rx [1006006.726180] CR2: 0000000000000020
Aug 7 07:26:17 rx [1006006.729718] ---[ end trace e0e2e37e4e612984 ]---

Prior to seeing the first crash and on other machines we also see the warning in
tcp_send_loss_probe() where packets_out is non-zero, but both transmit and retrans
queues are empty so we know the box is seeing some accounting issue in this area:

Jul 26 09:15:27 kernel: ------------[ cut here ]------------
Jul 26 09:15:27 kernel: invalid inflight: 2 state 1 cwnd 68 mss 8988
Jul 26 09:15:27 kernel: WARNING: CPU: 16 PID: 0 at net/ipv4/tcp_output.c:2605 tcp_send_loss_probe+0x214/0x220
Jul 26 09:15:27 kernel: Modules linked in: vrf bridge stp llc vxlan ip6_udp_tunnel udp_tunnel nls_iso8859_1 nft_ct amd64_edac_mod edac_mce_amd kvm_amd kvm crct10dif_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper wmi_bmof ipmi_ssif joydev input_leds rndis_host cdc_ether usbnet mii ast drm_vram_helper ttm drm_kms_he>
Jul 26 09:15:27 kernel: CPU: 16 PID: 0 Comm: swapper/16 Not tainted 5.4.0-174-generic #193-Ubuntu
Jul 26 09:15:27 kernel: Hardware name: Supermicro SMC 2x26 os-gen8 64C NVME-Y 256G/H12SSW-NTR, BIOS 2.5.V1.2U.NVMe.UEFI 05/09/2023
Jul 26 09:15:27 kernel: RIP: 0010:tcp_send_loss_probe+0x214/0x220
Jul 26 09:15:27 kernel: Code: 08 26 01 00 75 e2 41 0f b6 54 24 12 41 8b 8c 24 c0 06 00 00 45 89 f0 48 c7 c7 e0 b4 20 a7 c6 05 8d 08 26 01 01 e8 4a c0 0f 00 <0f> 0b eb ba 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41
Jul 26 09:15:27 kernel: RSP: 0018:ffffb7838088ce00 EFLAGS: 00010286
Jul 26 09:15:27 kernel: RAX: 0000000000000000 RBX: ffff9b84b5630430 RCX: 0000000000000006
Jul 26 09:15:27 kernel: RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff9b8e4621c8c0
Jul 26 09:15:27 kernel: RBP: ffffb7838088ce18 R08: 0000000000000927 R09: 0000000000000004
Jul 26 09:15:27 kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff9b84b5630000
Jul 26 09:15:27 kernel: R13: 0000000000000000 R14: 000000000000231c R15: ffff9b84b5630430
Jul 26 09:15:27 kernel: FS: 0000000000000000(0000) GS:ffff9b8e46200000(0000) knlGS:0000000000000000
Jul 26 09:15:27 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jul 26 09:15:27 kernel: CR2: 000056238cec2380 CR3: 0000003e49ede005 CR4: 0000000000760ee0
Jul 26 09:15:27 kernel: PKRU: 55555554
Jul 26 09:15:27 kernel: Call Trace:
Jul 26 09:15:27 kernel: <IRQ>
Jul 26 09:15:27 kernel: ? show_regs.cold+0x1a/0x1f
Jul 26 09:15:27 kernel: ? __warn+0x98/0xe0
Jul 26 09:15:27 kernel: ? tcp_send_loss_probe+0x214/0x220
Jul 26 09:15:27 kernel: ? report_bug+0xd1/0x100
Jul 26 09:15:27 kernel: ? do_error_trap+0x9b/0xc0
Jul 26 09:15:27 kernel: ? do_invalid_op+0x3c/0x50
Jul 26 09:15:27 kernel: ? tcp_send_loss_probe+0x214/0x220
Jul 26 09:15:27 kernel: ? invalid_op+0x1e/0x30
Jul 26 09:15:27 kernel: ? tcp_send_loss_probe+0x214/0x220
Jul 26 09:15:27 kernel: tcp_write_timer_handler+0x1b4/0x240
Jul 26 09:15:27 kernel: tcp_write_timer+0x9e/0xe0
Jul 26 09:15:27 kernel: ? tcp_write_timer_handler+0x240/0x240
Jul 26 09:15:27 kernel: call_timer_fn+0x32/0x130
Jul 26 09:15:27 kernel: __run_timers.part.0+0x180/0x280
Jul 26 09:15:27 kernel: ? timerqueue_add+0x9b/0xb0
Jul 26 09:15:27 kernel: ? enqueue_hrtimer+0x3d/0x90
Jul 26 09:15:27 kernel: ? do_error_trap+0x9b/0xc0
Jul 26 09:15:27 kernel: ? do_invalid_op+0x3c/0x50
Jul 26 09:15:27 kernel: ? tcp_send_loss_probe+0x214/0x220
Jul 26 09:15:27 kernel: ? invalid_op+0x1e/0x30
Jul 26 09:15:27 kernel: ? tcp_send_loss_probe+0x214/0x220
Jul 26 09:15:27 kernel: tcp_write_timer_handler+0x1b4/0x240
Jul 26 09:15:27 kernel: tcp_write_timer+0x9e/0xe0
Jul 26 09:15:27 kernel: ? tcp_write_timer_handler+0x240/0x240
Jul 26 09:15:27 kernel: call_timer_fn+0x32/0x130
Jul 26 09:15:27 kernel: __run_timers.part.0+0x180/0x280
Jul 26 09:15:27 kernel: ? timerqueue_add+0x9b/0xb0
Jul 26 09:15:27 kernel: ? enqueue_hrtimer+0x3d/0x90
Jul 26 09:15:27 kernel: ? recalibrate_cpu_khz+0x10/0x10
Jul 26 09:15:27 kernel: ? ktime_get+0x3e/0xa0
Jul 26 09:15:27 kernel: ? native_x2apic_icr_write+0x30/0x30
Jul 26 09:15:27 kernel: run_timer_softirq+0x2a/0x50
Jul 26 09:15:27 kernel: __do_softirq+0xd1/0x2c1
Jul 26 09:15:27 kernel: irq_exit+0xae/0xb0
Jul 26 09:15:27 kernel: smp_apic_timer_interrupt+0x7b/0x140
Jul 26 09:15:27 kernel: apic_timer_interrupt+0xf/0x20
Jul 26 09:15:27 kernel: </IRQ>
Jul 26 09:15:27 kernel: RIP: 0010:native_safe_halt+0xe/0x10
Jul 26 09:15:27 kernel: Code: 7b ff ff ff eb bd 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 36 2c 50 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 26 2c 50 00 fb f4 <c3> 90 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 e8 dd 5e 61 ff 65
Jul 26 09:15:27 kernel: RSP: 0018:ffffb783801cfe70 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
Jul 26 09:15:27 kernel: RAX: ffffffffa6908b20 RBX: 0000000000000010 RCX: 0000000000000001
Jul 26 09:15:27 kernel: RDX: 000000006fc0c97e RSI: 0000000000000082 RDI: 0000000000000082
Jul 26 09:15:27 kernel: RBP: ffffb783801cfe90 R08: 0000000000000000 R09: 0000000000000225
Jul 26 09:15:27 kernel: R10: 0000000000100000 R11: 0000000000000000 R12: 0000000000000010
Jul 26 09:15:27 kernel: R13: ffff9b8e390b0000 R14: 0000000000000000 R15: 0000000000000000
Jul 26 09:15:27 kernel: ? __cpuidle_text_start+0x8/0x8
Jul 26 09:15:27 kernel: ? default_idle+0x20/0x140
Jul 26 09:15:27 kernel: arch_cpu_idle+0x15/0x20
Jul 26 09:15:27 kernel: default_idle_call+0x23/0x30
Jul 26 09:15:27 kernel: do_idle+0x1fb/0x270
Jul 26 09:15:27 kernel: cpu_startup_entry+0x20/0x30
Jul 26 09:15:27 kernel: start_secondary+0x178/0x1d0
Jul 26 09:15:27 kernel: secondary_startup_64+0xa4/0xb0
Jul 26 09:15:27 kernel: ---[ end trace e7ac822987e33be1 ]---

The NULL ptr deref is coming from tcp_rto_delta_us() attempting to pull an skb
off the head of the retransmit queue and then dereferencing that skb to get the
skb_mstamp_ns value via tcp_skb_timestamp_us(skb).

The crash is the same one that was reported a # of years ago here:
https://lore.kernel.org/netdev/86c0f836-9a7c-438b-d81a-839be45f1f58@gmail.com/T/#t

and the kernel we're running has the fix which was added to resolve this issue.

Unfortunately we've been unsuccessful so far in reproducing this problem in the
lab and do not have the luxury of pushing out a new kernel to try and test if
newer kernels resolve this issue at the moment. I realize this is a report
against both an Ubuntu kernel and also an older 5.4 kernel. I have reported this
issue to Ubuntu here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2077657
however I feel like since this issue has possibly cropped up again it makes
sense to build in some protection in this path (even on the latest kernel
versions) since the code in question just blindly assumes there's a valid skb
without testing if it's NULL b/f it looks at the timestamp.

Given we have seen crashes in this path before and now this case it seems like
we should protect ourselves for when packets_out accounting is incorrect.
While we should fix that root cause we should also just make sure the skb
is not NULL before dereferencing it. Also add a warn once here to capture
some information if/when the problem case is hit again.

Fixes: e1a10ef7fa87 ("tcp: introduce tcp_rto_delta_us() helper for xmit timer fix")
Signed-off-by: Josh Hunt <johunt@akamai.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
mac80211: parse radiotap header when selecting Tx queue 2024-11-08T15:20:27+00:00 Mathy Vanhoef Mathy.Vanhoef@kuleuven.be 2020-07-23T10:01:53+00:00 73d2e264bd923627f7ee119e32020699e797db0f [ Upstream commit cb17ed29a7a5fea8c9bf70e8a05757d71650e025 ] Already parse the radiotap header in ieee80211_monitor_select_queue. In a subsequent commit this will allow us to add a radiotap flag that influences the queue on which injected packets will be sent. This also fixes the incomplete validation of the injected frame in ieee80211_monitor_select_queue: currently an out of bounds memory access may occur in in the called function ieee80211_select_queue_80211 if the 802.11 header is too small. Note that in ieee80211_monitor_start_xmit the radiotap header is parsed again, which is necessairy because ieee80211_monitor_select_queue is not always called beforehand. Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be> Link: https://lore.kernel.org/r/20200723100153.31631-6-Mathy.Vanhoef@kuleuven.be Signed-off-by: Johannes Berg <johannes.berg@intel.com> Stable-dep-of: 9d301de12da6 ("wifi: mac80211: use two-phase skb reclamation in ieee80211_do_stop()") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit cb17ed29a7a5fea8c9bf70e8a05757d71650e025 ]

Already parse the radiotap header in ieee80211_monitor_select_queue.
In a subsequent commit this will allow us to add a radiotap flag that
influences the queue on which injected packets will be sent.

This also fixes the incomplete validation of the injected frame in
ieee80211_monitor_select_queue: currently an out of bounds memory
access may occur in in the called function ieee80211_select_queue_80211
if the 802.11 header is too small.

Note that in ieee80211_monitor_start_xmit the radiotap header is parsed
again, which is necessairy because ieee80211_monitor_select_queue is not
always called beforehand.

Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
Link: https://lore.kernel.org/r/20200723100153.31631-6-Mathy.Vanhoef@kuleuven.be
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Stable-dep-of: 9d301de12da6 ("wifi: mac80211: use two-phase skb reclamation in ieee80211_do_stop()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: busy-poll: use ktime_get_ns() instead of local_clock() 2024-09-04T11:15:03+00:00 Eric Dumazet edumazet@google.com 2024-08-27T11:49:16+00:00 e7d364a5c705c4af3341cfa2dfa1c00bb7676c6e [ Upstream commit 0870b0d8b393dde53106678a1e2cec9dfa52f9b7 ] Typically, busy-polling durations are below 100 usec. When/if the busy-poller thread migrates to another cpu, local_clock() can be off by +/-2msec or more for small values of HZ, depending on the platform. Use ktimer_get_ns() to ensure deterministic behavior, which is the whole point of busy-polling. Fixes: 060212928670 ("net: add low latency socket poll") Fixes: 9a3c71aa8024 ("net: convert low latency sockets to sched_clock()") Fixes: 37089834528b ("sched, net: Fixup busy_loop_us_clock()") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Willem de Bruijn <willemb@google.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/20240827114916.223377-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0870b0d8b393dde53106678a1e2cec9dfa52f9b7 ]

Typically, busy-polling durations are below 100 usec.

When/if the busy-poller thread migrates to another cpu,
local_clock() can be off by +/-2msec or more for small
values of HZ, depending on the platform.

Use ktimer_get_ns() to ensure deterministic behavior,
which is the whole point of busy-polling.

Fixes: 060212928670 ("net: add low latency socket poll")
Fixes: 9a3c71aa8024 ("net: convert low latency sockets to sched_clock()")
Fixes: 37089834528b ("sched, net: Fixup busy_loop_us_clock()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/20240827114916.223377-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>