[syzbot] BUG: sleeping function called from invalid context in sk_psock_stop

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ff539ac73ea5 Add linux-next specific files for 20220609
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=176c121bf00000
kernel config: https://syzkaller.appspot.com/x/.config?x=a5002042f00a8bce
dashboard link: https://syzkaller.appspot.com/bug?extid=140186ceba0c496183bc
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13083353f00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=173e67f0080000

The issue was bisected to:

commit d8616ee2affcff37c5d315310da557a694a3303d
Author: Wang Yufen <wang...@huawei.com>
Date: Tue May 24 07:53:11 2022 +0000

bpf, sockmap: Fix sk->sk_forward_alloc warn_on in sk_stream_kill_queues

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1556d7cff00000
final oops: https://syzkaller.appspot.com/x/report.txt?x=1756d7cff00000
console output: https://syzkaller.appspot.com/x/log.txt?x=1356d7cff00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+140186...@syzkaller.appspotmail.com
Fixes: d8616ee2affc ("bpf, sockmap: Fix sk->sk_forward_alloc warn_on in sk_stream_kill_queues")

BUG: sleeping function called from invalid context at kernel/workqueue.c:3010
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 3612, name: syz-executor475
preempt_count: 201, expected: 0
RCU nest depth: 0, expected: 0
3 locks held by syz-executor475/3612:
#0: ffff888072eb9410 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:740 [inline]
#0: ffff888072eb9410 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:649
#1: ffff888027259ab0 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline]
#1: ffff888027259ab0 (sk_lock-AF_INET6){+.+.}-{0:0}, at: tcp_close+0x1e/0xc0 net/ipv4/tcp.c:2908
#2: ffff888027259a30 (slock-AF_INET6){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:360 [inline]
#2: ffff888027259a30 (slock-AF_INET6){+...}-{2:2}, at: __tcp_close+0x722/0x12b0 net/ipv4/tcp.c:2830
Preemption disabled at:
[<ffffffff87ddddca>] local_bh_disable include/linux/bottom_half.h:20 [inline]
[<ffffffff87ddddca>] __tcp_close+0x71a/0x12b0 net/ipv4/tcp.c:2829
CPU: 1 PID: 3612 Comm: syz-executor475 Not tainted 5.19.0-rc1-next-20220609-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
__might_resched.cold+0x222/0x26b kernel/sched/core.c:9823
start_flush_work kernel/workqueue.c:3010 [inline]
__flush_work+0x109/0xb10 kernel/workqueue.c:3074
__cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3162
sk_psock_stop+0x4cb/0x630 net/core/skmsg.c:802
sock_map_destroy+0x333/0x760 net/core/sock_map.c:1581
inet_csk_destroy_sock+0x196/0x440 net/ipv4/inet_connection_sock.c:1130
__tcp_close+0xd5b/0x12b0 net/ipv4/tcp.c:2897
tcp_close+0x29/0xc0 net/ipv4/tcp.c:2909
sock_map_close+0x3b9/0x780 net/core/sock_map.c:1607
inet_release+0x12e/0x280 net/ipv4/af_inet.c:428
inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:481
__sock_release+0xcd/0x280 net/socket.c:650
sock_close+0x18/0x20 net/socket.c:1365
__fput+0x277/0x9d0 fs/file_table.c:317
task_work_run+0xdd/0x1a0 kernel/task_work.c:177
ptrace_notify+0x114/0x140 kernel/signal.c:2353
ptrace_report_syscall include/linux/ptrace.h:420 [inline]
ptrace_report_syscall_exit include/linux/ptrace.h:482 [inline]
syscall_exit_work kernel/entry/common.c:249 [inline]
syscall_exit_to_user_mode_prepare+0xdb/0x230 kernel/entry/common.c:276
__syscall_exit_to_user_mode_work kernel/entry/common.c:281 [inline]
syscall_exit_to_user_mode+0x9/0x50 kernel/entry/common.c:294
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fe7b3b8b6a3
Code: c7 c2 c0 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb ba 0f 1f 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8
RSP: 002b:00007ffce5903258 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007fe7b3b8b6a3
RDX: 0000000000000020 RSI: 0000000020000240 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007fe7b3c36e40 R09: 00007fe7b3c36e40
R10: 00007fe7b3c36e40 R11: 0000000000000246 R12: 00007ffce5903290
R13: 00007ffce5903280 R14: 00007ffce5903270 R15: 0000000000000000
</TASK>


---
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

[Daniel Borkmann]

On 6/10/22 4:23 PM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: ff539ac73ea5 Add linux-next specific files for 20220609
> git tree: linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=176c121bf00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=a5002042f00a8bce
> dashboard link: https://syzkaller.appspot.com/bug?extid=140186ceba0c496183bc
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13083353f00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=173e67f0080000
>
> The issue was bisected to:
>
> commit d8616ee2affcff37c5d315310da557a694a3303d
> Author: Wang Yufen <wang...@huawei.com>
> Date: Tue May 24 07:53:11 2022 +0000
>
> bpf, sockmap: Fix sk->sk_forward_alloc warn_on in sk_stream_kill_queues

Same ping to Wang: Please take a look, otherwise we might need to revert if it stays unfixed.

[Hillf Danton]

On Fri, 10 Jun 2022 07:23:21 -0700

Given sk_psock_stop() in sk_psock_drop(), and cancel_work_sync() in
sk_psock_destroy(), make sock_map_destroy() NONBLOCK.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git ff539ac73ea5

--- y/net/core/sock_map.c
+++ x/net/core/sock_map.c
@@ -1578,7 +1578,7 @@ void sock_map_destroy(struct sock *sk)
saved_destroy = psock->saved_destroy;
sock_map_remove_links(sk, psock);
rcu_read_unlock();
- sk_psock_stop(psock, true);
+ sk_psock_stop(psock, false);
sk_psock_put(sk, psock);
saved_destroy(sk);
}
--

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+140186...@syzkaller.appspotmail.com

Tested on:

commit: ff539ac7 Add linux-next specific files for 20220609
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1462f61bf00000

kernel config: https://syzkaller.appspot.com/x/.config?x=a5002042f00a8bce
dashboard link: https://syzkaller.appspot.com/bug?extid=140186ceba0c496183bc
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=12a7d9bff00000

Note: testing is done by a robot and is best-effort only.

[wangyufen]

在 2022/6/10 22:35, Daniel Borkmann 写道:

On 6/10/22 4:23 PM, syzbot wrote:

Hello,

syzbot found the following issue on:

HEAD commit:    ff539ac73ea5 Add linux-next specific files for 20220609
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=176c121bf00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a5002042f00a8bce
dashboard link: https://syzkaller.appspot.com/bug?extid=140186ceba0c496183bc
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13083353f00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=173e67f0080000

The issue was bisected to:

commit d8616ee2affcff37c5d315310da557a694a3303d
Author: Wang Yufen <wang...@huawei.com>
Date:   Tue May 24 07:53:11 2022 +0000

     bpf, sockmap: Fix sk->sk_forward_alloc warn_on in sk_stream_kill_queues

Same ping to Wang: Please take a look, otherwise we might need to revert if it stays unfixed.

Thanks for Hillf's fix : https://groups.google.com/g/syzkaller-bugs/c/zunoClAqFQo/m/6SP7LIQoCQAJ

and sorry for the delay.

Thanks.

[Daniel Borkmann]

Please send this as a proper fix then, so it lands in patchwork and can be applied.

Thanks,
Daniel