* [syzbot] possible deadlock in smc_switch_to_fallback
@ 2021-11-20 2:47 syzbot
2021-11-20 3:48 ` Jakub Kicinski
2021-11-20 14:50 ` Pavel Skripkin
0 siblings, 2 replies; 4+ messages in thread
From: syzbot @ 2021-11-20 2:47 UTC (permalink / raw)
To: davem, kgraul, kuba, linux-kernel, linux-s390, netdev, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 9539ba4308ad Merge tag 'riscv-for-linus-5.16-rc2' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17f79d01b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=6d3b8fd1977c1e73
dashboard link: https://syzkaller.appspot.com/bug?extid=e979d3597f48262cb4ee
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e979d3597f48262cb4ee@syzkaller.appspotmail.com
============================================
WARNING: possible recursive locking detected
5.16.0-rc1-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.3/1337 is trying to acquire lock:
ffff88809466ce58 (&ei->socket.wq.wait){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
ffff88809466ce58 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3d5/0x8c0 net/smc/af_smc.c:588
but task is already holding lock:
ffff88809466c258 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3ca/0x8c0 net/smc/af_smc.c:587
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&ei->socket.wq.wait);
lock(&ei->socket.wq.wait);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syz-executor.3/1337:
#0:
ffff888082ba8120 (sk_lock-AF_SMC){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1645 [inline]
ffff888082ba8120 (sk_lock-AF_SMC){+.+.}-{0:0}, at: smc_setsockopt+0x2b7/0xa40 net/smc/af_smc.c:2449
#1: ffff88809466c258 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3ca/0x8c0 net/smc/af_smc.c:587
stack backtrace:
CPU: 1 PID: 1337 Comm: syz-executor.3 Not tainted 5.16.0-rc1-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
print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]
check_deadlock kernel/locking/lockdep.c:2999 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:349 [inline]
smc_switch_to_fallback+0x3d5/0x8c0 net/smc/af_smc.c:588
smc_setsockopt+0x8ee/0xa40 net/smc/af_smc.c:2459
__sys_setsockopt+0x2db/0x610 net/socket.c:2176
__do_sys_setsockopt net/socket.c:2187 [inline]
__se_sys_setsockopt net/socket.c:2184 [inline]
__x64_sys_setsockopt+0xba/0x150 net/socket.c:2184
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa2a8fceae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa2a6544188 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fa2a90e1f60 RCX: 00007fa2a8fceae9
RDX: 0000000000000021 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 00007fa2a9028f6d R08: 0000000000000010 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc2297067f R14: 00007fa2a6544300 R15: 0000000000022000
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [syzbot] possible deadlock in smc_switch_to_fallback
2021-11-20 2:47 [syzbot] possible deadlock in smc_switch_to_fallback syzbot
@ 2021-11-20 3:48 ` Jakub Kicinski
2021-11-22 3:41 ` Wen Gu
2021-11-20 14:50 ` Pavel Skripkin
1 sibling, 1 reply; 4+ messages in thread
From: Jakub Kicinski @ 2021-11-20 3:48 UTC (permalink / raw)
To: syzbot
Cc: davem, kgraul, linux-kernel, linux-s390, netdev, syzkaller-bugs,
Wen Gu, Dust Li
Adding Alibaba folks to CC.
On Fri, 19 Nov 2021 18:47:22 -0800 syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 9539ba4308ad Merge tag 'riscv-for-linus-5.16-rc2' of git:/..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17f79d01b00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=6d3b8fd1977c1e73
> dashboard link: https://syzkaller.appspot.com/bug?extid=e979d3597f48262cb4ee
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+e979d3597f48262cb4ee@syzkaller.appspotmail.com
>
> ============================================
> WARNING: possible recursive locking detected
> 5.16.0-rc1-syzkaller #0 Not tainted
> --------------------------------------------
> syz-executor.3/1337 is trying to acquire lock:
> ffff88809466ce58 (&ei->socket.wq.wait){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
> ffff88809466ce58 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3d5/0x8c0 net/smc/af_smc.c:588
>
> but task is already holding lock:
> ffff88809466c258 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3ca/0x8c0 net/smc/af_smc.c:587
>
> other info that might help us debug this:
> Possible unsafe locking scenario:
>
> CPU0
> ----
> lock(&ei->socket.wq.wait);
> lock(&ei->socket.wq.wait);
>
> *** DEADLOCK ***
>
> May be due to missing lock nesting notation
>
> 2 locks held by syz-executor.3/1337:
> #0:
> ffff888082ba8120 (sk_lock-AF_SMC){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1645 [inline]
> ffff888082ba8120 (sk_lock-AF_SMC){+.+.}-{0:0}, at: smc_setsockopt+0x2b7/0xa40 net/smc/af_smc.c:2449
> #1: ffff88809466c258 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3ca/0x8c0 net/smc/af_smc.c:587
>
> stack backtrace:
> CPU: 1 PID: 1337 Comm: syz-executor.3 Not tainted 5.16.0-rc1-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
> print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]
> check_deadlock kernel/locking/lockdep.c:2999 [inline]
> validate_chain kernel/locking/lockdep.c:3788 [inline]
> __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027
> lock_acquire kernel/locking/lockdep.c:5637 [inline]
> lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
> __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
> _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
> spin_lock include/linux/spinlock.h:349 [inline]
> smc_switch_to_fallback+0x3d5/0x8c0 net/smc/af_smc.c:588
> smc_setsockopt+0x8ee/0xa40 net/smc/af_smc.c:2459
> __sys_setsockopt+0x2db/0x610 net/socket.c:2176
> __do_sys_setsockopt net/socket.c:2187 [inline]
> __se_sys_setsockopt net/socket.c:2184 [inline]
> __x64_sys_setsockopt+0xba/0x150 net/socket.c:2184
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x44/0xae
> RIP: 0033:0x7fa2a8fceae9
> Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007fa2a6544188 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
> RAX: ffffffffffffffda RBX: 00007fa2a90e1f60 RCX: 00007fa2a8fceae9
> RDX: 0000000000000021 RSI: 0000000000000006 RDI: 0000000000000005
> RBP: 00007fa2a9028f6d R08: 0000000000000010 R09: 0000000000000000
> R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007ffc2297067f R14: 00007fa2a6544300 R15: 0000000000022000
> </TASK>
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [syzbot] possible deadlock in smc_switch_to_fallback
2021-11-20 2:47 [syzbot] possible deadlock in smc_switch_to_fallback syzbot
2021-11-20 3:48 ` Jakub Kicinski
@ 2021-11-20 14:50 ` Pavel Skripkin
1 sibling, 0 replies; 4+ messages in thread
From: Pavel Skripkin @ 2021-11-20 14:50 UTC (permalink / raw)
To: syzbot, davem, kgraul, kuba, linux-kernel, linux-s390, netdev,
syzkaller-bugs
On 11/20/21 05:47, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 9539ba4308ad Merge tag 'riscv-for-linus-5.16-rc2' of git:/..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17f79d01b00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=6d3b8fd1977c1e73
> dashboard link: https://syzkaller.appspot.com/bug?extid=e979d3597f48262cb4ee
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+e979d3597f48262cb4ee@syzkaller.appspotmail.com
>
> ============================================
> WARNING: possible recursive locking detected
> 5.16.0-rc1-syzkaller #0 Not tainted
> --------------------------------------------
> syz-executor.3/1337 is trying to acquire lock:
> ffff88809466ce58 (&ei->socket.wq.wait){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
> ffff88809466ce58 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3d5/0x8c0 net/smc/af_smc.c:588
> > but task is already holding lock:
> ffff88809466c258 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3ca/0x8c0 net/smc/af_smc.c:587
> > other info that might help us debug this:
> Possible unsafe locking scenario:
>
> CPU0
> ----
> lock(&ei->socket.wq.wait);
> lock(&ei->socket.wq.wait);
>
There is simple code block in net/smc/af_smc.c:
spin_lock_irqsave(&smc_wait->lock, flags);
spin_lock(&clc_wait->lock);
list_splice_init(&smc_wait->head, &clc_wait->head);
spin_unlock(&clc_wait->lock);
spin_unlock_irqrestore(&smc_wait->lock, flags);
smc_wait and clc_wait are too different pointers (based on report), but
these 2 different wait_queue locks registered to lockdep map via
sock_alloc_inode(), where init_waitqueue_head(&ei->socket.wq.wait); is
called. So any nested wait_queue_head_t locking will cause lockdep warning.
Have no idea how to handle it, just my thoughts about root case :)
With regards,
Pavel Skripkin
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [syzbot] possible deadlock in smc_switch_to_fallback
2021-11-20 3:48 ` Jakub Kicinski
@ 2021-11-22 3:41 ` Wen Gu
0 siblings, 0 replies; 4+ messages in thread
From: Wen Gu @ 2021-11-22 3:41 UTC (permalink / raw)
To: Jakub Kicinski
Cc: davem, kgraul, linux-kernel, linux-s390, netdev, syzkaller-bugs,
Dust Li, paskripkin
On 2021/11/20 11:48 am, Jakub Kicinski wrote:
> Adding Alibaba folks to CC.
>
> On Fri, 19 Nov 2021 18:47:22 -0800 syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 9539ba4308ad Merge tag 'riscv-for-linus-5.16-rc2' of git:/..
>> git tree: upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=17f79d01b00000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=6d3b8fd1977c1e73
>> dashboard link: https://syzkaller.appspot.com/bug?extid=e979d3597f48262cb4ee
>> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>>
>> Unfortunately, I don't have any reproducer for this issue yet.
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+e979d3597f48262cb4ee@syzkaller.appspotmail.com
>>
>> ============================================
>> WARNING: possible recursive locking detected
>> 5.16.0-rc1-syzkaller #0 Not tainted
>> --------------------------------------------
>> syz-executor.3/1337 is trying to acquire lock:
>> ffff88809466ce58 (&ei->socket.wq.wait){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
>> ffff88809466ce58 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3d5/0x8c0 net/smc/af_smc.c:588
>>
>> but task is already holding lock:
>> ffff88809466c258 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3ca/0x8c0 net/smc/af_smc.c:587
>>
>> other info that might help us debug this:
>> Possible unsafe locking scenario:
>>
>> CPU0
>> ----
>> lock(&ei->socket.wq.wait);
>> lock(&ei->socket.wq.wait);
>>
>> *** DEADLOCK ***
>>
>> May be due to missing lock nesting notation
>>
>> 2 locks held by syz-executor.3/1337:
>> #0:
>> ffff888082ba8120 (sk_lock-AF_SMC){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1645 [inline]
>> ffff888082ba8120 (sk_lock-AF_SMC){+.+.}-{0:0}, at: smc_setsockopt+0x2b7/0xa40 net/smc/af_smc.c:2449
>> #1: ffff88809466c258 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3ca/0x8c0 net/smc/af_smc.c:587
>>
>> stack backtrace:
>> CPU: 1 PID: 1337 Comm: syz-executor.3 Not tainted 5.16.0-rc1-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
>> print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]
>> check_deadlock kernel/locking/lockdep.c:2999 [inline]
>> validate_chain kernel/locking/lockdep.c:3788 [inline]
>> __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027
>> lock_acquire kernel/locking/lockdep.c:5637 [inline]
>> lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
>> __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
>> _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
>> spin_lock include/linux/spinlock.h:349 [inline]
>> smc_switch_to_fallback+0x3d5/0x8c0 net/smc/af_smc.c:588
>> smc_setsockopt+0x8ee/0xa40 net/smc/af_smc.c:2459
>> __sys_setsockopt+0x2db/0x610 net/socket.c:2176
>> __do_sys_setsockopt net/socket.c:2187 [inline]
>> __se_sys_setsockopt net/socket.c:2184 [inline]
>> __x64_sys_setsockopt+0xba/0x150 net/socket.c:2184
>> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>> do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
>> entry_SYSCALL_64_after_hwframe+0x44/0xae
>> RIP: 0033:0x7fa2a8fceae9
>> Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
>> RSP: 002b:00007fa2a6544188 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
>> RAX: ffffffffffffffda RBX: 00007fa2a90e1f60 RCX: 00007fa2a8fceae9
>> RDX: 0000000000000021 RSI: 0000000000000006 RDI: 0000000000000005
>> RBP: 00007fa2a9028f6d R08: 0000000000000010 R09: 0000000000000000
>> R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000
>> R13: 00007ffc2297067f R14: 00007fa2a6544300 R15: 0000000000022000
>> </TASK>
>>
>>
>> ---
>> This report is generated by a bot. It may contain errors.
>> See https://goo.gl/tpsmEJ for more information about syzbot.
>> syzbot engineers can be reached at syzkaller@googlegroups.com.
>>
>> syzbot will keep track of this issue. See:
>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
We take this issue seriously and have started an investigation.
Thanks,
Wen Gu
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-11-22 3:41 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2021-11-20 2:47 [syzbot] possible deadlock in smc_switch_to_fallback syzbot
2021-11-20 3:48 ` Jakub Kicinski
2021-11-22 3:41 ` Wen Gu
2021-11-20 14:50 ` Pavel Skripkin
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