commit 62ec33b44e0f7168ff2886520fec6fb62d03b5a3 upstream.
Christoph Paasch reported that commit b5fc29233d28 ("inet6: Remove
inet6_destroy_sock() in sk->sk_prot->destroy().") started triggering
WARN_ON_ONCE(sk->sk_forward_alloc) in sk_stream_kill_queues(). [0 - 2]
Also, we can reproduce it by a program in [3].
In the commit, we delay freeing ipv6_pinfo.pktoptions from sk->destroy()
to sk->sk_destruct(), so sk->sk_forward_alloc is no longer zero in
inet_csk_destroy_sock().
The same check has been in inet_sock_destruct() from at least v2.6,
we can just remove the WARN_ON_ONCE(). However, among the users of
sk_stream_kill_queues(), only CAIF is not calling inet_sock_destruct().
Thus, we add the same WARN_ON_ONCE() to caif_sock_destructor().
[0]: https://lore.kernel.org/netdev/39725AB4-88F1-41B3-B07F-949C5CAEFF4F@xxxxxxxxxx/
[1]: https://github.com/multipath-tcp/mptcp_net-next/issues/341
[2]:
WARNING: CPU: 0 PID: 3232 at net/core/stream.c:212 sk_stream_kill_queues+0x2f9/0x3e0
Modules linked in:
CPU: 0 PID: 3232 Comm: syz-executor.0 Not tainted 6.2.0-rc5ab24eb4698afbe147b424149c529e2a43ec24eb5 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:sk_stream_kill_queues+0x2f9/0x3e0
Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e ec 00 00 00 8b ab 08 01 00 00 e9 60 ff ff ff e8 d0 5f b6 fe 0f 0b eb 97 e8 c7 5f b6 fe <0f> 0b eb a0 e8 be 5f b6 fe 0f 0b e9 6a fe ff ff e8 02 07 e3 fe e9
RSP: 0018:ffff88810570fc68 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888101f38f40 RSI: ffffffff8285e529 RDI: 0000000000000005
RBP: 0000000000000ce0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000ce0 R11: 0000000000000001 R12: ffff8881009e9488
R13: ffffffff84af2cc0 R14: 0000000000000000 R15: ffff8881009e9458
FS: 00007f7fdfbd5800(0000) GS:ffff88811b600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32923000 CR3: 00000001062fc006 CR4: 0000000000170ef0
Call Trace:
<TASK>
inet_csk_destroy_sock+0x1a1/0x320
__tcp_close+0xab6/0xe90
tcp_close+0x30/0xc0
inet_release+0xe9/0x1f0
inet6_release+0x4c/0x70
__sock_release+0xd2/0x280
sock_close+0x15/0x20
__fput+0x252/0xa20
task_work_run+0x169/0x250
exit_to_user_mode_prepare+0x113/0x120
syscall_exit_to_user_mode+0x1d/0x40
do_syscall_64+0x48/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7f7fdf7ae28d
Code: c1 20 00 00 75 10 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 37 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00000000007dfbb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f7fdf7ae28d
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000003
RBP: 0000000000000000 R08: 000000007f338e0f R09: 0000000000000e0f
R10: 000000007f338e13 R11: 0000000000000293 R12: 00007f7fdefff000
R13: 00007f7fdefffcd8 R14: 00007f7fdefffce0 R15: 00007f7fdefffcd8
</TASK>
[3]: https://lore.kernel.org/netdev/20230208004245.83497-1-kuniyu@xxxxxxxxxx/
Fixes: b5fc29233d28 ("inet6: Remove inet6_destroy_sock() in sk->sk_prot->destroy().")
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Reported-by: Christoph Paasch <christophpaasch@xxxxxxxxxx>
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
---
This can be applied on 5.15.95, 5.10.170, 5.4.233, 4.19.274, and 4.14.307.
When resolving a conflict with c59f02f84867 ("net: use WARN_ON_ONCE() in
sk_stream_kill_queues()"), I have changed WARN_ON_ONCE() to WARN_ON() to
keep consistency.
---
net/caif/caif_socket.c | 1 +
net/core/stream.c | 1 -
2 files changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index e12fd3cad619..997c4ebdce6f 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -1020,6 +1020,7 @@ static void caif_sock_destructor(struct sock *sk)
return;
}
sk_stream_kill_queues(&cf_sk->sk);
+ WARN_ON(sk->sk_forward_alloc);
caif_free_client(&cf_sk->layer);
}
diff --git a/net/core/stream.c b/net/core/stream.c
index d7c5413d16d5..cd60746877b1 100644
--- a/net/core/stream.c
+++ b/net/core/stream.c
@@ -209,7 +209,6 @@ void sk_stream_kill_queues(struct sock *sk)
sk_mem_reclaim(sk);
WARN_ON(sk->sk_wmem_queued);
- WARN_ON(sk->sk_forward_alloc);
/* It is _impossible_ for the backlog to contain anything
* when we get here. All user references to this socket
--
2.38.1
