linux-stable.git/net/ipv4, branch v6.0.3 Linux kernel stable tree net-next: Fix IP_UNICAST_IF option behavior for connected sockets 2022-10-21T10:39:07+00:00 Richard Gobert richardbgobert@gmail.com 2022-08-29T11:18:51+00:00 45304d0db4b592343d753ef922f96ef0ceed62ab [ Upstream commit 0e4d354762cefd3e16b4cff8988ff276e45effc4 ] The IP_UNICAST_IF socket option is used to set the outgoing interface for outbound packets. The IP_UNICAST_IF socket option was added as it was needed by the Wine project, since no other existing option (SO_BINDTODEVICE socket option, IP_PKTINFO socket option or the bind function) provided the needed characteristics needed by the IP_UNICAST_IF socket option. [1] The IP_UNICAST_IF socket option works well for unconnected sockets, that is, the interface specified by the IP_UNICAST_IF socket option is taken into consideration in the route lookup process when a packet is being sent. However, for connected sockets, the outbound interface is chosen when connecting the socket, and in the route lookup process which is done when a packet is being sent, the interface specified by the IP_UNICAST_IF socket option is being ignored. This inconsistent behavior was reported and discussed in an issue opened on systemd's GitHub project [2]. Also, a bug report was submitted in the kernel's bugzilla [3]. To understand the problem in more detail, we can look at what happens for UDP packets over IPv4 (The same analysis was done separately in the referenced systemd issue). When a UDP packet is sent the udp_sendmsg function gets called and the following happens: 1. The oif member of the struct ipcm_cookie ipc (which stores the output interface of the packet) is initialized by the ipcm_init_sk function to inet->sk.sk_bound_dev_if (the device set by the SO_BINDTODEVICE socket option). 2. If the IP_PKTINFO socket option was set, the oif member gets overridden by the call to the ip_cmsg_send function. 3. If no output interface was selected yet, the interface specified by the IP_UNICAST_IF socket option is used. 4. If the socket is connected and no destination address is specified in the send function, the struct ipcm_cookie ipc is not taken into consideration and the cached route, that was calculated in the connect function is being used. Thus, for a connected socket, the IP_UNICAST_IF sockopt isn't taken into consideration. This patch corrects the behavior of the IP_UNICAST_IF socket option for connect()ed sockets by taking into consideration the IP_UNICAST_IF sockopt when connecting the socket. In order to avoid reconnecting the socket, this option is still ignored when applied on an already connected socket until connect() is called again by the Richard Gobert. Change the __ip4_datagram_connect function, which is called during socket connection, to take into consideration the interface set by the IP_UNICAST_IF socket option, in a similar way to what is done in the udp_sendmsg function. [1] https://lore.kernel.org/netdev/1328685717.4736.4.camel@edumazet-laptop/T/ [2] https://github.com/systemd/systemd/issues/11935#issuecomment-618691018 [3] https://bugzilla.kernel.org/show_bug.cgi?id=210255 Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20220829111554.GA1771@debian Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0e4d354762cefd3e16b4cff8988ff276e45effc4 ]

The IP_UNICAST_IF socket option is used to set the outgoing interface
for outbound packets.

The IP_UNICAST_IF socket option was added as it was needed by the
Wine project, since no other existing option (SO_BINDTODEVICE socket
option, IP_PKTINFO socket option or the bind function) provided the
needed characteristics needed by the IP_UNICAST_IF socket option. [1]
The IP_UNICAST_IF socket option works well for unconnected sockets,
that is, the interface specified by the IP_UNICAST_IF socket option
is taken into consideration in the route lookup process when a packet
is being sent. However, for connected sockets, the outbound interface
is chosen when connecting the socket, and in the route lookup process
which is done when a packet is being sent, the interface specified by
the IP_UNICAST_IF socket option is being ignored.

This inconsistent behavior was reported and discussed in an issue
opened on systemd's GitHub project [2]. Also, a bug report was
submitted in the kernel's bugzilla [3].

To understand the problem in more detail, we can look at what happens
for UDP packets over IPv4 (The same analysis was done separately in
the referenced systemd issue).
When a UDP packet is sent the udp_sendmsg function gets called and
the following happens:

1. The oif member of the struct ipcm_cookie ipc (which stores the
output interface of the packet) is initialized by the ipcm_init_sk
function to inet->sk.sk_bound_dev_if (the device set by the
SO_BINDTODEVICE socket option).

2. If the IP_PKTINFO socket option was set, the oif member gets
overridden by the call to the ip_cmsg_send function.

3. If no output interface was selected yet, the interface specified
by the IP_UNICAST_IF socket option is used.

4. If the socket is connected and no destination address is
specified in the send function, the struct ipcm_cookie ipc is not
taken into consideration and the cached route, that was calculated in
the connect function is being used.

Thus, for a connected socket, the IP_UNICAST_IF sockopt isn't taken
into consideration.

This patch corrects the behavior of the IP_UNICAST_IF socket option
for connect()ed sockets by taking into consideration the
IP_UNICAST_IF sockopt when connecting the socket.

In order to avoid reconnecting the socket, this option is still
ignored when applied on an already connected socket until connect()
is called again by the Richard Gobert.

Change the __ip4_datagram_connect function, which is called during
socket connection, to take into consideration the interface set by
the IP_UNICAST_IF socket option, in a similar way to what is done in
the udp_sendmsg function.

[1] https://lore.kernel.org/netdev/1328685717.4736.4.camel@edumazet-laptop/T/
[2] https://github.com/systemd/systemd/issues/11935#issuecomment-618691018
[3] https://bugzilla.kernel.org/show_bug.cgi?id=210255

Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220829111554.GA1771@debian
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp: annotate data-race around tcp_md5sig_pool_populated 2022-10-21T10:39:06+00:00 Eric Dumazet edumazet@google.com 2022-08-22T21:15:28+00:00 7afdf41db86541bad0a2427f2fdec052351202d4 [ Upstream commit aacd467c0a576e5e44d2de4205855dc0fe43f6fb ] tcp_md5sig_pool_populated can be read while another thread changes its value. The race has no consequence because allocations are protected with tcp_md5sig_mutex. This patch adds READ_ONCE() and WRITE_ONCE() to document the race and silence KCSAN. Reported-by: Abhishek Shah <abhishek.shah@columbia.edu> Signed-off-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 aacd467c0a576e5e44d2de4205855dc0fe43f6fb ]

tcp_md5sig_pool_populated can be read while another thread
changes its value.

The race has no consequence because allocations
are protected with tcp_md5sig_mutex.

This patch adds READ_ONCE() and WRITE_ONCE() to document
the race and silence KCSAN.

Reported-by: Abhishek Shah <abhishek.shah@columbia.edu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
once: add DO_ONCE_SLOW() for sleepable contexts 2022-10-21T10:38:21+00:00 Eric Dumazet edumazet@google.com 2022-10-01T20:51:02+00:00 d36404f21bb9c0682e2419325ff6b384a19cc1ba [ Upstream commit 62c07983bef9d3e78e71189441e1a470f0d1e653 ] Christophe Leroy reported a ~80ms latency spike happening at first TCP connect() time. This is because __inet_hash_connect() uses get_random_once() to populate a perturbation table which became quite big after commit 4c2c8f03a5ab ("tcp: increase source port perturb table to 2^16") get_random_once() uses DO_ONCE(), which block hard irqs for the duration of the operation. This patch adds DO_ONCE_SLOW() which uses a mutex instead of a spinlock for operations where we prefer to stay in process context. Then __inet_hash_connect() can use get_random_slow_once() to populate its perturbation table. Fixes: 4c2c8f03a5ab ("tcp: increase source port perturb table to 2^16") Fixes: 190cc82489f4 ("tcp: change source port randomizarion at connect() time") Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> Link: https://lore.kernel.org/netdev/CANn89iLAEYBaoYajy0Y9UmGFff5GPxDUoG-ErVB2jDdRNQ5Tug@mail.gmail.com/T/#t Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willy Tarreau <w@1wt.eu> Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 62c07983bef9d3e78e71189441e1a470f0d1e653 ]

Christophe Leroy reported a ~80ms latency spike
happening at first TCP connect() time.

This is because __inet_hash_connect() uses get_random_once()
to populate a perturbation table which became quite big
after commit 4c2c8f03a5ab ("tcp: increase source port perturb table to 2^16")

get_random_once() uses DO_ONCE(), which block hard irqs for the duration
of the operation.

This patch adds DO_ONCE_SLOW() which uses a mutex instead of a spinlock
for operations where we prefer to stay in process context.

Then __inet_hash_connect() can use get_random_slow_once()
to populate its perturbation table.

Fixes: 4c2c8f03a5ab ("tcp: increase source port perturb table to 2^16")
Fixes: 190cc82489f4 ("tcp: change source port randomizarion at connect() time")
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/netdev/CANn89iLAEYBaoYajy0Y9UmGFff5GPxDUoG-ErVB2jDdRNQ5Tug@mail.gmail.com/T/#t
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willy Tarreau <w@1wt.eu>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp: fix tcp_cwnd_validate() to not forget is_cwnd_limited 2022-10-21T10:38:19+00:00 Neal Cardwell ncardwell@google.com 2022-09-28T20:03:31+00:00 0fbdebca088fa8f7621dc5c036e76d3d898a135d [ Upstream commit f4ce91ce12a7c6ead19b128ffa8cff6e3ded2a14 ] This commit fixes a bug in the tracking of max_packets_out and is_cwnd_limited. This bug can cause the connection to fail to remember that is_cwnd_limited is true, causing the connection to fail to grow cwnd when it should, causing throughput to be lower than it should be. The following event sequence is an example that triggers the bug: (a) The connection is cwnd_limited, but packets_out is not at its peak due to TSO deferral deciding not to send another skb yet. In such cases the connection can advance max_packets_seq and set tp->is_cwnd_limited to true and max_packets_out to a small number. (b) Then later in the round trip the connection is pacing-limited (not cwnd-limited), and packets_out is larger. In such cases the connection would raise max_packets_out to a bigger number but (unexpectedly) flip tp->is_cwnd_limited from true to false. This commit fixes that bug. One straightforward fix would be to separately track (a) the next window after max_packets_out reaches a maximum, and (b) the next window after tp->is_cwnd_limited is set to true. But this would require consuming an extra u32 sequence number. Instead, to save space we track only the most important information. Specifically, we track the strongest available signal of the degree to which the cwnd is fully utilized: (1) If the connection is cwnd-limited then we remember that fact for the current window. (2) If the connection not cwnd-limited then we track the maximum number of outstanding packets in the current window. In particular, note that the new logic cannot trigger the buggy (a)/(b) sequence above because with the new logic a condition where tp->packets_out > tp->max_packets_out can only trigger an update of tp->is_cwnd_limited if tp->is_cwnd_limited is false. This first showed up in a testing of a BBRv2 dev branch, but this buggy behavior highlighted a general issue with the tcp_cwnd_validate() logic that can cause cwnd to fail to increase at the proper rate for any TCP congestion control, including Reno or CUBIC. Fixes: ca8a22634381 ("tcp: make cwnd-limited checks measurement-based, and gentler") Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Kevin(Yudong) Yang <yyd@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-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 f4ce91ce12a7c6ead19b128ffa8cff6e3ded2a14 ]

This commit fixes a bug in the tracking of max_packets_out and
is_cwnd_limited. This bug can cause the connection to fail to remember
that is_cwnd_limited is true, causing the connection to fail to grow
cwnd when it should, causing throughput to be lower than it should be.

The following event sequence is an example that triggers the bug:

 (a) The connection is cwnd_limited, but packets_out is not at its
     peak due to TSO deferral deciding not to send another skb yet.
     In such cases the connection can advance max_packets_seq and set
     tp->is_cwnd_limited to true and max_packets_out to a small
     number.

(b) Then later in the round trip the connection is pacing-limited (not
     cwnd-limited), and packets_out is larger. In such cases the
     connection would raise max_packets_out to a bigger number but
     (unexpectedly) flip tp->is_cwnd_limited from true to false.

This commit fixes that bug.

One straightforward fix would be to separately track (a) the next
window after max_packets_out reaches a maximum, and (b) the next
window after tp->is_cwnd_limited is set to true. But this would
require consuming an extra u32 sequence number.

Instead, to save space we track only the most important
information. Specifically, we track the strongest available signal of
the degree to which the cwnd is fully utilized:

(1) If the connection is cwnd-limited then we remember that fact for
the current window.

(2) If the connection not cwnd-limited then we track the maximum
number of outstanding packets in the current window.

In particular, note that the new logic cannot trigger the buggy
(a)/(b) sequence above because with the new logic a condition where
tp->packets_out > tp->max_packets_out can only trigger an update of
tp->is_cwnd_limited if tp->is_cwnd_limited is false.

This first showed up in a testing of a BBRv2 dev branch, but this
buggy behavior highlighted a general issue with the
tcp_cwnd_validate() logic that can cause cwnd to fail to increase at
the proper rate for any TCP congestion control, including Reno or
CUBIC.

Fixes: ca8a22634381 ("tcp: make cwnd-limited checks measurement-based, and gentler")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Kevin(Yudong) Yang <yyd@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
netfilter: nft_fib: Fix for rpath check with VRF devices 2022-10-21T10:38:18+00:00 Phil Sutter phil@nwl.cc 2022-09-21T11:07:31+00:00 c63f45b4a94b619738f778e1f134934aa9bc4554 [ Upstream commit 2a8a7c0eaa8747c16aa4a48d573aa920d5c00a5c ] Analogous to commit b575b24b8eee3 ("netfilter: Fix rpfilter dropping vrf packets by mistake") but for nftables fib expression: Add special treatment of VRF devices so that typical reverse path filtering via 'fib saddr . iif oif' expression works as expected. Fixes: f6d0cbcf09c50 ("netfilter: nf_tables: add fib expression") Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2a8a7c0eaa8747c16aa4a48d573aa920d5c00a5c ]

Analogous to commit b575b24b8eee3 ("netfilter: Fix rpfilter
dropping vrf packets by mistake") but for nftables fib expression:
Add special treatment of VRF devices so that typical reverse path
filtering via 'fib saddr . iif oif' expression works as expected.

Fixes: f6d0cbcf09c50 ("netfilter: nf_tables: add fib expression")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
esp: choose the correct inner protocol for GSO on inter address family tunnels 2022-10-21T10:38:04+00:00 Sabrina Dubroca sd@queasysnail.net 2022-08-25T15:16:51+00:00 bf137a3c97727cdeafde339286d09a67bdf4be2b [ Upstream commit 26dbd66eab8080be51759e48280da04015221e22 ] Commit 23c7f8d7989e ("net: Fix esp GSO on inter address family tunnels.") is incomplete. It passes to skb_eth_gso_segment the protocol for the outer IP version, instead of the inner IP version, so we end up calling inet_gso_segment on an inner IPv6 packet and ipv6_gso_segment on an inner IPv4 packet and the packets are dropped. This patch completes the fix by selecting the correct protocol based on the inner mode's family. Fixes: c35fe4106b92 ("xfrm: Add mode handlers for IPsec on layer 2") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 26dbd66eab8080be51759e48280da04015221e22 ]

Commit 23c7f8d7989e ("net: Fix esp GSO on inter address family
tunnels.") is incomplete. It passes to skb_eth_gso_segment the
protocol for the outer IP version, instead of the inner IP version, so
we end up calling inet_gso_segment on an inner IPv6 packet and
ipv6_gso_segment on an inner IPv4 packet and the packets are dropped.

This patch completes the fix by selecting the correct protocol based
on the inner mode's family.

Fixes: c35fe4106b92 ("xfrm: Add mode handlers for IPsec on layer 2")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
udp: Use WARN_ON_ONCE() in udp_read_skb() 2022-09-22T13:42:57+00:00 Peilin Ye peilin.ye@bytedance.com 2022-09-21T00:59:15+00:00 db39dfdc1c3bd9da273902da12f01973792ff911 Prevent udp_read_skb() from flooding the syslog. Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Peilin Ye <peilin.ye@bytedance.com> Link: https://lore.kernel.org/r/20220921005915.2697-1-yepeilin.cs@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Prevent udp_read_skb() from flooding the syslog.

Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Link: https://lore.kernel.org/r/20220921005915.2697-1-yepeilin.cs@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipmr: Always call ip{,6}_mr_forward() from RCU read-side critical section 2022-09-20T15:22:15+00:00 Ido Schimmel idosch@nvidia.com 2022-09-14T07:53:38+00:00 b07a9b26e2b1aa3711fd6935eccb08a463b1fb11 These functions expect to be called from RCU read-side critical section, but this only happens when invoked from the data path via ip{,6}_mr_input(). They can also be invoked from process context in response to user space adding a multicast route which resolves a cache entry with queued packets [1][2]. Fix by adding missing rcu_read_lock() / rcu_read_unlock() in these call paths. [1] WARNING: suspicious RCU usage 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted ----------------------------- net/ipv4/ipmr.c:84 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by smcrouted/246: #0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip_mroute_setsockopt+0x11c/0x1420 stack backtrace: CPU: 0 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x91/0xb9 vif_dev_read+0xbf/0xd0 ipmr_queue_xmit+0x135/0x1ab0 ip_mr_forward+0xe7b/0x13d0 ipmr_mfc_add+0x1a06/0x2ad0 ip_mroute_setsockopt+0x5c1/0x1420 do_ip_setsockopt+0x23d/0x37f0 ip_setsockopt+0x56/0x80 raw_setsockopt+0x219/0x290 __sys_setsockopt+0x236/0x4d0 __x64_sys_setsockopt+0xbe/0x160 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd [2] WARNING: suspicious RCU usage 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted ----------------------------- net/ipv6/ip6mr.c:69 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by smcrouted/246: #0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip6_mroute_setsockopt+0x6b9/0x2630 stack backtrace: CPU: 1 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x91/0xb9 vif_dev_read+0xbf/0xd0 ip6mr_forward2.isra.0+0xc9/0x1160 ip6_mr_forward+0xef0/0x13f0 ip6mr_mfc_add+0x1ff2/0x31f0 ip6_mroute_setsockopt+0x1825/0x2630 do_ipv6_setsockopt+0x462/0x4440 ipv6_setsockopt+0x105/0x140 rawv6_setsockopt+0xd8/0x690 __sys_setsockopt+0x236/0x4d0 __x64_sys_setsockopt+0xbe/0x160 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: ebc3197963fc ("ipmr: add rcu protection over (struct vif_device)->dev") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
These functions expect to be called from RCU read-side critical section,
but this only happens when invoked from the data path via
ip{,6}_mr_input(). They can also be invoked from process context in
response to user space adding a multicast route which resolves a cache
entry with queued packets [1][2].

Fix by adding missing rcu_read_lock() / rcu_read_unlock() in these call
paths.

[1]
WARNING: suspicious RCU usage
6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted
-----------------------------
net/ipv4/ipmr.c:84 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by smcrouted/246:
 #0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip_mroute_setsockopt+0x11c/0x1420

stack backtrace:
CPU: 0 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x91/0xb9
 vif_dev_read+0xbf/0xd0
 ipmr_queue_xmit+0x135/0x1ab0
 ip_mr_forward+0xe7b/0x13d0
 ipmr_mfc_add+0x1a06/0x2ad0
 ip_mroute_setsockopt+0x5c1/0x1420
 do_ip_setsockopt+0x23d/0x37f0
 ip_setsockopt+0x56/0x80
 raw_setsockopt+0x219/0x290
 __sys_setsockopt+0x236/0x4d0
 __x64_sys_setsockopt+0xbe/0x160
 do_syscall_64+0x34/0x80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

[2]
WARNING: suspicious RCU usage
6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted
-----------------------------
net/ipv6/ip6mr.c:69 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by smcrouted/246:
 #0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip6_mroute_setsockopt+0x6b9/0x2630

stack backtrace:
CPU: 1 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x91/0xb9
 vif_dev_read+0xbf/0xd0
 ip6mr_forward2.isra.0+0xc9/0x1160
 ip6_mr_forward+0xef0/0x13f0
 ip6mr_mfc_add+0x1ff2/0x31f0
 ip6_mroute_setsockopt+0x1825/0x2630
 do_ipv6_setsockopt+0x462/0x4440
 ipv6_setsockopt+0x105/0x140
 rawv6_setsockopt+0xd8/0x690
 __sys_setsockopt+0x236/0x4d0
 __x64_sys_setsockopt+0xbe/0x160
 do_syscall_64+0x34/0x80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: ebc3197963fc ("ipmr: add rcu protection over (struct vif_device)->dev")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tcp: read multiple skbs in tcp_read_skb() 2022-09-20T12:47:21+00:00 Cong Wang cong.wang@bytedance.com 2022-09-12T17:35:53+00:00 db4192a754ebd52300a28abe1a50dd18eae0eb12 Before we switched to ->read_skb(), ->read_sock() was passed with desc.count=1, which technically indicates we only read one skb per ->sk_data_ready() call. However, for TCP, this is not true. TCP at least has sk_rcvlowat which intentionally holds skb's in receive queue until this watermark is reached. This means when ->sk_data_ready() is invoked there could be multiple skb's in the queue, therefore we have to read multiple skbs in tcp_read_skb() instead of one. Fixes: 965b57b469a5 ("net: Introduce a new proto_ops ->read_skb()") Reported-by: Peilin Ye <peilin.ye@bytedance.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Jakub Sitnicki <jakub@cloudflare.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Link: https://lore.kernel.org/r/20220912173553.235838-1-xiyou.wangcong@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
Before we switched to ->read_skb(), ->read_sock() was passed with
desc.count=1, which technically indicates we only read one skb per
->sk_data_ready() call. However, for TCP, this is not true.

TCP at least has sk_rcvlowat which intentionally holds skb's in
receive queue until this watermark is reached. This means when
->sk_data_ready() is invoked there could be multiple skb's in the
queue, therefore we have to read multiple skbs in tcp_read_skb()
instead of one.

Fixes: 965b57b469a5 ("net: Introduce a new proto_ops ->read_skb()")
Reported-by: Peilin Ye <peilin.ye@bytedance.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Link: https://lore.kernel.org/r/20220912173553.235838-1-xiyou.wangcong@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
tcp: Use WARN_ON_ONCE() in tcp_read_skb() 2022-09-16T14:29:19+00:00 Peilin Ye peilin.ye@bytedance.com 2022-09-08T23:15:23+00:00 96628951869c0dedf0377adca01c8675172d8639 Prevent tcp_read_skb() from flooding the syslog. Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Peilin Ye <peilin.ye@bytedance.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Prevent tcp_read_skb() from flooding the syslog.

Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>