linux-stable.git/net/ipv4, branch v5.15.136 Linux kernel stable tree tcp: fix delayed ACKs for MSS boundary condition 2023-10-10T19:59:08+00:00 Neal Cardwell ncardwell@google.com 2023-10-01T15:12:39+00:00 1abac613c0d52d883ee46db30308875b6abaefe6 [ Upstream commit 4720852ed9afb1c5ab84e96135cb5b73d5afde6f ] This commit fixes poor delayed ACK behavior that can cause poor TCP latency in a particular boundary condition: when an application makes a TCP socket write that is an exact multiple of the MSS size. The problem is that there is painful boundary discontinuity in the current delayed ACK behavior. With the current delayed ACK behavior, we have: (1) If an app reads data when > 1*MSS is unacknowledged, then tcp_cleanup_rbuf() ACKs immediately because of: tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || (2) If an app reads all received data, and the packets were < 1*MSS, and either (a) the app is not ping-pong or (b) we received two packets < 1*MSS, then tcp_cleanup_rbuf() ACKs immediately beecause of: ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && !inet_csk_in_pingpong_mode(sk))) && (3) *However*: if an app reads exactly 1*MSS of data, tcp_cleanup_rbuf() does not send an immediate ACK. This is true even if the app is not ping-pong and the 1*MSS of data had the PSH bit set, suggesting the sending application completed an application write. Thus if the app is not ping-pong, we have this painful case where >1*MSS gets an immediate ACK, and <1*MSS gets an immediate ACK, but a write whose last skb is an exact multiple of 1*MSS can get a 40ms delayed ACK. This means that any app that transfers data in one direction and takes care to align write size or packet size with MSS can suffer this problem. With receive zero copy making 4KB MSS values more common, it is becoming more common to have application writes naturally align with MSS, and more applications are likely to encounter this delayed ACK problem. The fix in this commit is to refine the delayed ACK heuristics with a simple check: immediately ACK a received 1*MSS skb with PSH bit set if the app reads all data. Why? If an skb has a len of exactly 1*MSS and has the PSH bit set then it is likely the end of an application write. So more data may not be arriving soon, and yet the data sender may be waiting for an ACK if cwnd-bound or using TX zero copy. Thus we set ICSK_ACK_PUSHED in this case so that tcp_cleanup_rbuf() will send an ACK immediately if the app reads all of the data and is not ping-pong. Note that this logic is also executed for the case where len > MSS, but in that case this logic does not matter (and does not hurt) because tcp_cleanup_rbuf() will always ACK immediately if the app reads data and there is more than an MSS of unACKed data. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Cc: Xin Guo <guoxin0309@gmail.com> Link: https://lore.kernel.org/r/20231001151239.1866845-2-ncardwell.sw@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4720852ed9afb1c5ab84e96135cb5b73d5afde6f ]

This commit fixes poor delayed ACK behavior that can cause poor TCP
latency in a particular boundary condition: when an application makes
a TCP socket write that is an exact multiple of the MSS size.

The problem is that there is painful boundary discontinuity in the
current delayed ACK behavior. With the current delayed ACK behavior,
we have:

(1) If an app reads data when > 1*MSS is unacknowledged, then
    tcp_cleanup_rbuf() ACKs immediately because of:

     tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||

(2) If an app reads all received data, and the packets were < 1*MSS,
    and either (a) the app is not ping-pong or (b) we received two
    packets < 1*MSS, then tcp_cleanup_rbuf() ACKs immediately beecause
    of:

     ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
      ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
       !inet_csk_in_pingpong_mode(sk))) &&

(3) *However*: if an app reads exactly 1*MSS of data,
    tcp_cleanup_rbuf() does not send an immediate ACK. This is true
    even if the app is not ping-pong and the 1*MSS of data had the PSH
    bit set, suggesting the sending application completed an
    application write.

Thus if the app is not ping-pong, we have this painful case where
>1*MSS gets an immediate ACK, and <1*MSS gets an immediate ACK, but a
write whose last skb is an exact multiple of 1*MSS can get a 40ms
delayed ACK. This means that any app that transfers data in one
direction and takes care to align write size or packet size with MSS
can suffer this problem. With receive zero copy making 4KB MSS values
more common, it is becoming more common to have application writes
naturally align with MSS, and more applications are likely to
encounter this delayed ACK problem.

The fix in this commit is to refine the delayed ACK heuristics with a
simple check: immediately ACK a received 1*MSS skb with PSH bit set if
the app reads all data. Why? If an skb has a len of exactly 1*MSS and
has the PSH bit set then it is likely the end of an application
write. So more data may not be arriving soon, and yet the data sender
may be waiting for an ACK if cwnd-bound or using TX zero copy. Thus we
set ICSK_ACK_PUSHED in this case so that tcp_cleanup_rbuf() will send
an ACK immediately if the app reads all of the data and is not
ping-pong. Note that this logic is also executed for the case where
len > MSS, but in that case this logic does not matter (and does not
hurt) because tcp_cleanup_rbuf() will always ACK immediately if the
app reads data and there is more than an MSS of unACKed data.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Cc: Xin Guo <guoxin0309@gmail.com>
Link: https://lore.kernel.org/r/20231001151239.1866845-2-ncardwell.sw@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp: fix quick-ack counting to count actual ACKs of new data 2023-10-10T19:59:08+00:00 Neal Cardwell ncardwell@google.com 2023-10-01T15:12:38+00:00 821b3b00bc0fbe72f50d5a347ed0b8a57209fd7b [ Upstream commit 059217c18be6757b95bfd77ba53fb50b48b8a816 ] This commit fixes quick-ack counting so that it only considers that a quick-ack has been provided if we are sending an ACK that newly acknowledges data. The code was erroneously using the number of data segments in outgoing skbs when deciding how many quick-ack credits to remove. This logic does not make sense, and could cause poor performance in request-response workloads, like RPC traffic, where requests or responses can be multi-segment skbs. When a TCP connection decides to send N quick-acks, that is to accelerate the cwnd growth of the congestion control module controlling the remote endpoint of the TCP connection. That quick-ack decision is purely about the incoming data and outgoing ACKs. It has nothing to do with the outgoing data or the size of outgoing data. And in particular, an ACK only serves the intended purpose of allowing the remote congestion control to grow the congestion window quickly if the ACK is ACKing or SACKing new data. The fix is simple: only count packets as serving the goal of the quickack mechanism if they are ACKing/SACKing new data. We can tell whether this is the case by checking inet_csk_ack_scheduled(), since we schedule an ACK exactly when we are ACKing/SACKing new data. Fixes: fc6415bcb0f5 ("[TCP]: Fix quick-ack decrementing with TSO.") Signed-off-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20231001151239.1866845-1-ncardwell.sw@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 059217c18be6757b95bfd77ba53fb50b48b8a816 ]

This commit fixes quick-ack counting so that it only considers that a
quick-ack has been provided if we are sending an ACK that newly
acknowledges data.

The code was erroneously using the number of data segments in outgoing
skbs when deciding how many quick-ack credits to remove. This logic
does not make sense, and could cause poor performance in
request-response workloads, like RPC traffic, where requests or
responses can be multi-segment skbs.

When a TCP connection decides to send N quick-acks, that is to
accelerate the cwnd growth of the congestion control module
controlling the remote endpoint of the TCP connection. That quick-ack
decision is purely about the incoming data and outgoing ACKs. It has
nothing to do with the outgoing data or the size of outgoing data.

And in particular, an ACK only serves the intended purpose of allowing
the remote congestion control to grow the congestion window quickly if
the ACK is ACKing or SACKing new data.

The fix is simple: only count packets as serving the goal of the
quickack mechanism if they are ACKing/SACKing new data. We can tell
whether this is the case by checking inet_csk_ack_scheduled(), since
we schedule an ACK exactly when we are ACKing/SACKing new data.

Fixes: fc6415bcb0f5 ("[TCP]: Fix quick-ack decrementing with TSO.")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231001151239.1866845-1-ncardwell.sw@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipv4: Set offload_failed flag in fibmatch results 2023-10-10T19:59:08+00:00 Benjamin Poirier bpoirier@nvidia.com 2023-09-26T18:27:30+00:00 74e569324050ad49759b9a4e80bab35e0f4527c0 [ Upstream commit 0add5c597f3253a9c6108a0a81d57f44ab0d9d30 ] Due to a small omission, the offload_failed flag is missing from ipv4 fibmatch results. Make sure it is set correctly. The issue can be witnessed using the following commands: echo "1 1" > /sys/bus/netdevsim/new_device ip link add dummy1 up type dummy ip route add 192.0.2.0/24 dev dummy1 echo 1 > /sys/kernel/debug/netdevsim/netdevsim1/fib/fail_route_offload ip route add 198.51.100.0/24 dev dummy1 ip route # 192.168.15.0/24 has rt_trap # 198.51.100.0/24 has rt_offload_failed ip route get 192.168.15.1 fibmatch # Result has rt_trap ip route get 198.51.100.1 fibmatch # Result differs from the route shown by `ip route`, it is missing # rt_offload_failed ip link del dev dummy1 echo 1 > /sys/bus/netdevsim/del_device Fixes: 36c5100e859d ("IPv4: Add "offload failed" indication to routes") Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20230926182730.231208-1-bpoirier@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0add5c597f3253a9c6108a0a81d57f44ab0d9d30 ]

Due to a small omission, the offload_failed flag is missing from ipv4
fibmatch results. Make sure it is set correctly.

The issue can be witnessed using the following commands:
echo "1 1" > /sys/bus/netdevsim/new_device
ip link add dummy1 up type dummy
ip route add 192.0.2.0/24 dev dummy1
echo 1 > /sys/kernel/debug/netdevsim/netdevsim1/fib/fail_route_offload
ip route add 198.51.100.0/24 dev dummy1
ip route
	# 192.168.15.0/24 has rt_trap
	# 198.51.100.0/24 has rt_offload_failed
ip route get 192.168.15.1 fibmatch
	# Result has rt_trap
ip route get 198.51.100.1 fibmatch
	# Result differs from the route shown by `ip route`, it is missing
	# rt_offload_failed
ip link del dev dummy1
echo 1 > /sys/bus/netdevsim/del_device

Fixes: 36c5100e859d ("IPv4: Add "offload failed" indication to routes")
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230926182730.231208-1-bpoirier@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipv4: fix null-deref in ipv4_link_failure 2023-10-06T11:18:06+00:00 Kyle Zeng zengyhkyle@gmail.com 2023-09-15T05:12:57+00:00 8860d354f653628b6330e1c5b06b2828948135a4 [ Upstream commit 0113d9c9d1ccc07f5a3710dac4aa24b6d711278c ] Currently, we assume the skb is associated with a device before calling __ip_options_compile, which is not always the case if it is re-routed by ipvs. When skb->dev is NULL, dev_net(skb->dev) will become null-dereference. This patch adds a check for the edge case and switch to use the net_device from the rtable when skb->dev is NULL. Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure") Suggested-by: David Ahern <dsahern@kernel.org> Signed-off-by: Kyle Zeng <zengyhkyle@gmail.com> Cc: Stephen Suryaputra <ssuryaextr@gmail.com> Cc: Vadim Fedorenko <vfedorenko@novek.ru> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0113d9c9d1ccc07f5a3710dac4aa24b6d711278c ]

Currently, we assume the skb is associated with a device before calling
__ip_options_compile, which is not always the case if it is re-routed by
ipvs.
When skb->dev is NULL, dev_net(skb->dev) will become null-dereference.
This patch adds a check for the edge case and switch to use the net_device
from the rtable when skb->dev is NULL.

Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure")
Suggested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Kyle Zeng <zengyhkyle@gmail.com>
Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
Cc: Vadim Fedorenko <vfedorenko@novek.ru>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: ipv4: fix one memleak in __inet_del_ifa() 2023-09-19T10:23:03+00:00 Liu Jian liujian56@huawei.com 2023-09-07T02:57:09+00:00 2f1e86014d0cc084886c36a2d77bc620e2d42618 [ Upstream commit ac28b1ec6135649b5d78b028e47264cb3ebca5ea ] I got the below warning when do fuzzing test: unregister_netdevice: waiting for bond0 to become free. Usage count = 2 It can be repoduced via: ip link add bond0 type bond sysctl -w net.ipv4.conf.bond0.promote_secondaries=1 ip addr add 4.117.174.103/0 scope 0x40 dev bond0 ip addr add 192.168.100.111/255.255.255.254 scope 0 dev bond0 ip addr add 0.0.0.4/0 scope 0x40 secondary dev bond0 ip addr del 4.117.174.103/0 scope 0x40 dev bond0 ip link delete bond0 type bond In this reproduction test case, an incorrect 'last_prim' is found in __inet_del_ifa(), as a result, the secondary address(0.0.0.4/0 scope 0x40) is lost. The memory of the secondary address is leaked and the reference of in_device and net_device is leaked. Fix this problem: Look for 'last_prim' starting at location of the deleted IP and inserting the promoted IP into the location of 'last_prim'. Fixes: 0ff60a45678e ("[IPV4]: Fix secondary IP addresses after promotion") Signed-off-by: Liu Jian <liujian56@huawei.com> Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ac28b1ec6135649b5d78b028e47264cb3ebca5ea ]

I got the below warning when do fuzzing test:
unregister_netdevice: waiting for bond0 to become free. Usage count = 2

It can be repoduced via:

ip link add bond0 type bond
sysctl -w net.ipv4.conf.bond0.promote_secondaries=1
ip addr add 4.117.174.103/0 scope 0x40 dev bond0
ip addr add 192.168.100.111/255.255.255.254 scope 0 dev bond0
ip addr add 0.0.0.4/0 scope 0x40 secondary dev bond0
ip addr del 4.117.174.103/0 scope 0x40 dev bond0
ip link delete bond0 type bond

In this reproduction test case, an incorrect 'last_prim' is found in
__inet_del_ifa(), as a result, the secondary address(0.0.0.4/0 scope 0x40)
is lost. The memory of the secondary address is leaked and the reference of
in_device and net_device is leaked.

Fix this problem:
Look for 'last_prim' starting at location of the deleted IP and inserting
the promoted IP into the location of 'last_prim'.

Fixes: 0ff60a45678e ("[IPV4]: Fix secondary IP addresses after promotion")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipv4: ignore dst hint for multipath routes 2023-09-19T10:22:58+00:00 Sriram Yagnaraman sriram.yagnaraman@est.tech 2023-08-31T08:03:30+00:00 149bc7834d6fde88e896d61bd98fff9027681581 [ Upstream commit 6ac66cb03ae306c2e288a9be18226310529f5b25 ] Route hints when the nexthop is part of a multipath group causes packets in the same receive batch to be sent to the same nexthop irrespective of the multipath hash of the packet. So, do not extract route hint for packets whose destination is part of a multipath group. A new SKB flag IPSKB_MULTIPATH is introduced for this purpose, set the flag when route is looked up in ip_mkroute_input() and use it in ip_extract_route_hint() to check for the existence of the flag. Fixes: 02b24941619f ("ipv4: use dst hint for ipv4 list receive") Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@est.tech> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 6ac66cb03ae306c2e288a9be18226310529f5b25 ]

Route hints when the nexthop is part of a multipath group causes packets
in the same receive batch to be sent to the same nexthop irrespective of
the multipath hash of the packet. So, do not extract route hint for
packets whose destination is part of a multipath group.

A new SKB flag IPSKB_MULTIPATH is introduced for this purpose, set the
flag when route is looked up in ip_mkroute_input() and use it in
ip_extract_route_hint() to check for the existence of the flag.

Fixes: 02b24941619f ("ipv4: use dst hint for ipv4 list receive")
Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@est.tech>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipv4: annotate data-races around fi->fib_dead 2023-09-19T10:22:58+00:00 Eric Dumazet edumazet@google.com 2023-08-30T09:55:20+00:00 e0b483a0584f451aae95b61acd8bcda788d4f773 [ Upstream commit fce92af1c29d90184dfec638b5738831097d66e9 ] syzbot complained about a data-race in fib_table_lookup() [1] Add appropriate annotations to document it. [1] BUG: KCSAN: data-race in fib_release_info / fib_table_lookup write to 0xffff888150f31744 of 1 bytes by task 1189 on cpu 0: fib_release_info+0x3a0/0x460 net/ipv4/fib_semantics.c:281 fib_table_delete+0x8d2/0x900 net/ipv4/fib_trie.c:1777 fib_magic+0x1c1/0x1f0 net/ipv4/fib_frontend.c:1106 fib_del_ifaddr+0x8cf/0xa60 net/ipv4/fib_frontend.c:1317 fib_inetaddr_event+0x77/0x200 net/ipv4/fib_frontend.c:1448 notifier_call_chain kernel/notifier.c:93 [inline] blocking_notifier_call_chain+0x90/0x200 kernel/notifier.c:388 __inet_del_ifa+0x4df/0x800 net/ipv4/devinet.c:432 inet_del_ifa net/ipv4/devinet.c:469 [inline] inetdev_destroy net/ipv4/devinet.c:322 [inline] inetdev_event+0x553/0xaf0 net/ipv4/devinet.c:1606 notifier_call_chain kernel/notifier.c:93 [inline] raw_notifier_call_chain+0x6b/0x1c0 kernel/notifier.c:461 call_netdevice_notifiers_info net/core/dev.c:1962 [inline] call_netdevice_notifiers_mtu+0xd2/0x130 net/core/dev.c:2037 dev_set_mtu_ext+0x30b/0x3e0 net/core/dev.c:8673 do_setlink+0x5be/0x2430 net/core/rtnetlink.c:2837 rtnl_setlink+0x255/0x300 net/core/rtnetlink.c:3177 rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6445 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2549 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6463 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg net/socket.c:748 [inline] sock_write_iter+0x1aa/0x230 net/socket.c:1129 do_iter_write+0x4b4/0x7b0 fs/read_write.c:860 vfs_writev+0x1a8/0x320 fs/read_write.c:933 do_writev+0xf8/0x220 fs/read_write.c:976 __do_sys_writev fs/read_write.c:1049 [inline] __se_sys_writev fs/read_write.c:1046 [inline] __x64_sys_writev+0x45/0x50 fs/read_write.c:1046 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff888150f31744 of 1 bytes by task 21839 on cpu 1: fib_table_lookup+0x2bf/0xd50 net/ipv4/fib_trie.c:1585 fib_lookup include/net/ip_fib.h:383 [inline] ip_route_output_key_hash_rcu+0x38c/0x12c0 net/ipv4/route.c:2751 ip_route_output_key_hash net/ipv4/route.c:2641 [inline] __ip_route_output_key include/net/route.h:134 [inline] ip_route_output_flow+0xa6/0x150 net/ipv4/route.c:2869 send4+0x1e7/0x500 drivers/net/wireguard/socket.c:61 wg_socket_send_skb_to_peer+0x94/0x130 drivers/net/wireguard/socket.c:175 wg_socket_send_buffer_to_peer+0xd6/0x100 drivers/net/wireguard/socket.c:200 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x10c/0x150 drivers/net/wireguard/send.c:51 process_one_work+0x434/0x860 kernel/workqueue.c:2600 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2751 kthread+0x1d7/0x210 kernel/kthread.c:389 ret_from_fork+0x2e/0x40 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 value changed: 0x00 -> 0x01 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 21839 Comm: kworker/u4:18 Tainted: G W 6.5.0-syzkaller #0 Fixes: dccd9ecc3744 ("ipv4: Do not use dead fib_info entries.") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20230830095520.1046984-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit fce92af1c29d90184dfec638b5738831097d66e9 ]

syzbot complained about a data-race in fib_table_lookup() [1]

Add appropriate annotations to document it.

[1]
BUG: KCSAN: data-race in fib_release_info / fib_table_lookup

write to 0xffff888150f31744 of 1 bytes by task 1189 on cpu 0:
fib_release_info+0x3a0/0x460 net/ipv4/fib_semantics.c:281
fib_table_delete+0x8d2/0x900 net/ipv4/fib_trie.c:1777
fib_magic+0x1c1/0x1f0 net/ipv4/fib_frontend.c:1106
fib_del_ifaddr+0x8cf/0xa60 net/ipv4/fib_frontend.c:1317
fib_inetaddr_event+0x77/0x200 net/ipv4/fib_frontend.c:1448
notifier_call_chain kernel/notifier.c:93 [inline]
blocking_notifier_call_chain+0x90/0x200 kernel/notifier.c:388
__inet_del_ifa+0x4df/0x800 net/ipv4/devinet.c:432
inet_del_ifa net/ipv4/devinet.c:469 [inline]
inetdev_destroy net/ipv4/devinet.c:322 [inline]
inetdev_event+0x553/0xaf0 net/ipv4/devinet.c:1606
notifier_call_chain kernel/notifier.c:93 [inline]
raw_notifier_call_chain+0x6b/0x1c0 kernel/notifier.c:461
call_netdevice_notifiers_info net/core/dev.c:1962 [inline]
call_netdevice_notifiers_mtu+0xd2/0x130 net/core/dev.c:2037
dev_set_mtu_ext+0x30b/0x3e0 net/core/dev.c:8673
do_setlink+0x5be/0x2430 net/core/rtnetlink.c:2837
rtnl_setlink+0x255/0x300 net/core/rtnetlink.c:3177
rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6445
netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2549
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6463
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1914
sock_sendmsg_nosec net/socket.c:725 [inline]
sock_sendmsg net/socket.c:748 [inline]
sock_write_iter+0x1aa/0x230 net/socket.c:1129
do_iter_write+0x4b4/0x7b0 fs/read_write.c:860
vfs_writev+0x1a8/0x320 fs/read_write.c:933
do_writev+0xf8/0x220 fs/read_write.c:976
__do_sys_writev fs/read_write.c:1049 [inline]
__se_sys_writev fs/read_write.c:1046 [inline]
__x64_sys_writev+0x45/0x50 fs/read_write.c:1046
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888150f31744 of 1 bytes by task 21839 on cpu 1:
fib_table_lookup+0x2bf/0xd50 net/ipv4/fib_trie.c:1585
fib_lookup include/net/ip_fib.h:383 [inline]
ip_route_output_key_hash_rcu+0x38c/0x12c0 net/ipv4/route.c:2751
ip_route_output_key_hash net/ipv4/route.c:2641 [inline]
__ip_route_output_key include/net/route.h:134 [inline]
ip_route_output_flow+0xa6/0x150 net/ipv4/route.c:2869
send4+0x1e7/0x500 drivers/net/wireguard/socket.c:61
wg_socket_send_skb_to_peer+0x94/0x130 drivers/net/wireguard/socket.c:175
wg_socket_send_buffer_to_peer+0xd6/0x100 drivers/net/wireguard/socket.c:200
wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline]
wg_packet_handshake_send_worker+0x10c/0x150 drivers/net/wireguard/send.c:51
process_one_work+0x434/0x860 kernel/workqueue.c:2600
worker_thread+0x5f2/0xa10 kernel/workqueue.c:2751
kthread+0x1d7/0x210 kernel/kthread.c:389
ret_from_fork+0x2e/0x40 arch/x86/kernel/process.c:145
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 21839 Comm: kworker/u4:18 Tainted: G W 6.5.0-syzkaller #0

Fixes: dccd9ecc3744 ("ipv4: Do not use dead fib_info entries.")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230830095520.1046984-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU 2023-09-19T10:22:49+00:00 Eric Dumazet edumazet@google.com 2023-09-05T04:23:38+00:00 3e48f741e98a0bd2dc1ad517eec1931ea3accbd7 commit c3b704d4a4a265660e665df51b129e8425216ed1 upstream. This is a follow up of commit 915d975b2ffa ("net: deal with integer overflows in kmalloc_reserve()") based on David Laight feedback. Back in 2010, I failed to realize malicious users could set dev->mtu to arbitrary values. This mtu has been since limited to 0x7fffffff but regardless of how big dev->mtu is, it makes no sense for igmpv3_newpack() to allocate more than IP_MAX_MTU and risk various skb fields overflows. Fixes: 57e1ab6eaddc ("igmp: refine skb allocations") Link: https://lore.kernel.org/netdev/d273628df80f45428e739274ab9ecb72@AcuMS.aculab.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: David Laight <David.Laight@ACULAB.COM> Cc: Kyle Zeng <zengyhkyle@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c3b704d4a4a265660e665df51b129e8425216ed1 upstream.

This is a follow up of commit 915d975b2ffa ("net: deal with integer
overflows in kmalloc_reserve()") based on David Laight feedback.

Back in 2010, I failed to realize malicious users could set dev->mtu
to arbitrary values. This mtu has been since limited to 0x7fffffff but
regardless of how big dev->mtu is, it makes no sense for igmpv3_newpack()
to allocate more than IP_MAX_MTU and risk various skb fields overflows.

Fixes: 57e1ab6eaddc ("igmp: refine skb allocations")
Link: https://lore.kernel.org/netdev/d273628df80f45428e739274ab9ecb72@AcuMS.aculab.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: David Laight <David.Laight@ACULAB.COM>
Cc: Kyle Zeng <zengyhkyle@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
lwt: Check LWTUNNEL_XMIT_CONTINUE strictly 2023-09-19T10:22:34+00:00 Yan Zhai yan@cloudflare.com 2023-08-18T02:58:14+00:00 f683992d30ee5c2f27d633e7f8c9abe93eae13f7 [ Upstream commit a171fbec88a2c730b108c7147ac5e7b2f5a02b47 ] LWTUNNEL_XMIT_CONTINUE is implicitly assumed in ip(6)_finish_output2, such that any positive return value from a xmit hook could cause unexpected continue behavior, despite that related skb may have been freed. This could be error-prone for future xmit hook ops. One of the possible errors is to return statuses of dst_output directly. To make the code safer, redefine LWTUNNEL_XMIT_CONTINUE value to distinguish from dst_output statuses and check the continue condition explicitly. Fixes: 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure") Suggested-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Yan Zhai <yan@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/96b939b85eda00e8df4f7c080f770970a4c5f698.1692326837.git.yan@cloudflare.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a171fbec88a2c730b108c7147ac5e7b2f5a02b47 ]

LWTUNNEL_XMIT_CONTINUE is implicitly assumed in ip(6)_finish_output2,
such that any positive return value from a xmit hook could cause
unexpected continue behavior, despite that related skb may have been
freed. This could be error-prone for future xmit hook ops. One of the
possible errors is to return statuses of dst_output directly.

To make the code safer, redefine LWTUNNEL_XMIT_CONTINUE value to
distinguish from dst_output statuses and check the continue
condition explicitly.

Fixes: 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure")
Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/96b939b85eda00e8df4f7c080f770970a4c5f698.1692326837.git.yan@cloudflare.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: tcp: fix unexcepted socket die when snd_wnd is 0 2023-09-19T10:22:33+00:00 Menglong Dong imagedong@tencent.com 2023-08-11T02:55:29+00:00 50c78e71446dd9cda3c68ea6466085f46ebfd22b [ Upstream commit e89688e3e97868451a5d05b38a9d2633d6785cd4 ] In tcp_retransmit_timer(), a window shrunk connection will be regarded as timeout if 'tcp_jiffies32 - tp->rcv_tstamp > TCP_RTO_MAX'. This is not right all the time. The retransmits will become zero-window probes in tcp_retransmit_timer() if the 'snd_wnd==0'. Therefore, the icsk->icsk_rto will come up to TCP_RTO_MAX sooner or later. However, the timer can be delayed and be triggered after 122877ms, not TCP_RTO_MAX, as I tested. Therefore, 'tcp_jiffies32 - tp->rcv_tstamp > TCP_RTO_MAX' is always true once the RTO come up to TCP_RTO_MAX, and the socket will die. Fix this by replacing the 'tcp_jiffies32' with '(u32)icsk->icsk_timeout', which is exact the timestamp of the timeout. However, "tp->rcv_tstamp" can restart from idle, then tp->rcv_tstamp could already be a long time (minutes or hours) in the past even on the first RTO. So we double check the timeout with the duration of the retransmission. Meanwhile, making "2 * TCP_RTO_MAX" as the timeout to avoid the socket dying too soon. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Link: https://lore.kernel.org/netdev/CADxym3YyMiO+zMD4zj03YPM3FBi-1LHi6gSD2XT8pyAMM096pg@mail.gmail.com/ Signed-off-by: Menglong Dong <imagedong@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e89688e3e97868451a5d05b38a9d2633d6785cd4 ]

In tcp_retransmit_timer(), a window shrunk connection will be regarded
as timeout if 'tcp_jiffies32 - tp->rcv_tstamp > TCP_RTO_MAX'. This is not
right all the time.

The retransmits will become zero-window probes in tcp_retransmit_timer()
if the 'snd_wnd==0'. Therefore, the icsk->icsk_rto will come up to
TCP_RTO_MAX sooner or later.

However, the timer can be delayed and be triggered after 122877ms, not
TCP_RTO_MAX, as I tested.

Therefore, 'tcp_jiffies32 - tp->rcv_tstamp > TCP_RTO_MAX' is always true
once the RTO come up to TCP_RTO_MAX, and the socket will die.

Fix this by replacing the 'tcp_jiffies32' with '(u32)icsk->icsk_timeout',
which is exact the timestamp of the timeout.

However, "tp->rcv_tstamp" can restart from idle, then tp->rcv_tstamp
could already be a long time (minutes or hours) in the past even on the
first RTO. So we double check the timeout with the duration of the
retransmission.

Meanwhile, making "2 * TCP_RTO_MAX" as the timeout to avoid the socket
dying too soon.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://lore.kernel.org/netdev/CADxym3YyMiO+zMD4zj03YPM3FBi-1LHi6gSD2XT8pyAMM096pg@mail.gmail.com/
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>