INFO: trying to register non-static key in io_cqring_ev_posted (3)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: ac935d22 Add linux-next specific files for 20200415
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=12deaa5e100000
kernel config: https://syzkaller.appspot.com/x/.config?x=bc498783097e9019
dashboard link: https://syzkaller.appspot.com/bug?extid=8c91f5d054e998721c57
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11d54c02100000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17461e06100000

The bug was bisected to:

commit b41e98524e424d104aa7851d54fd65820759875a
Author: Jens Axboe <ax...@kernel.dk>
Date: Mon Feb 17 16:52:41 2020 +0000

io_uring: add per-task callback handler

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1488dc3c100000
final crash: https://syzkaller.appspot.com/x/report.txt?x=1688dc3c100000
console output: https://syzkaller.appspot.com/x/log.txt?x=1288dc3c100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+8c91f5...@syzkaller.appspotmail.com
Fixes: b41e98524e42 ("io_uring: add per-task callback handler")

RSP: 002b:00007fffb1fb9aa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441319
RDX: 0000000000000001 RSI: 0000000020000140 RDI: 000000000000047b
RBP: 0000000000010475 R08: 0000000000000001 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402260
R13: 00000000004022f0 R14: 0000000000000000 R15: 0000000000000000
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 1 PID: 7090 Comm: syz-executor222 Not tainted 5.7.0-rc1-next-20200415-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x188/0x20d lib/dump_stack.c:118
assign_lock_key kernel/locking/lockdep.c:913 [inline]
register_lock_class+0x1664/0x1760 kernel/locking/lockdep.c:1225
__lock_acquire+0x104/0x4c50 kernel/locking/lockdep.c:4234
lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159
__wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:122
io_cqring_ev_posted+0xa5/0x1e0 fs/io_uring.c:1160
io_poll_remove_all fs/io_uring.c:4357 [inline]
io_ring_ctx_wait_and_kill+0x2bc/0x5a0 fs/io_uring.c:7305
io_uring_create fs/io_uring.c:7843 [inline]
io_uring_setup+0x115e/0x22b0 fs/io_uring.c:7870
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x441319
Code: e8 5c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffb1fb9aa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441319
RDX: 0000000000000001 RSI: 0000000020000140 RDI: 000000000000047b
RBP: 0000000000010475 R08: 0000000000000001 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402260
R13: 00000000004022f0 R14: 0000000000000000 R15: 0000000000000000
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 7090 Comm: syz-executor222 Not tainted 5.7.0-rc1-next-20200415-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:232 [inline]
RIP: 0010:__wake_up_common+0xdc/0x600 kernel/sched/wait.c:86
Code: b9 04 00 00 4c 8b 43 40 49 83 e8 18 49 8d 78 18 48 39 fd 0f 84 d0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 e3 04 00 00 49 bd 00 00 00 00 00 fc ff df 4d 8b
RSP: 0018:ffffc90001677c20 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffff8880a6081120 RCX: 1ffffffff1517002
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: ffff8880a6081160 R08: ffffffffffffffe8 R09: ffffc90001677cb8
R10: 0000000000000003 R11: fffff520002cef7e R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000
FS: 000000000136f880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000140 CR3: 00000000936b4000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:123
io_cqring_ev_posted+0xa5/0x1e0 fs/io_uring.c:1160
io_poll_remove_all fs/io_uring.c:4357 [inline]
io_ring_ctx_wait_and_kill+0x2bc/0x5a0 fs/io_uring.c:7305
io_uring_create fs/io_uring.c:7843 [inline]
io_uring_setup+0x115e/0x22b0 fs/io_uring.c:7870
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x441319
Code: e8 5c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffb1fb9aa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441319
RDX: 0000000000000001 RSI: 0000000020000140 RDI: 000000000000047b
RBP: 0000000000010475 R08: 0000000000000001 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402260
R13: 00000000004022f0 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace bf24b131500537a6 ]---
RIP: 0010:__read_once_size include/linux/compiler.h:232 [inline]
RIP: 0010:__wake_up_common+0xdc/0x600 kernel/sched/wait.c:86
Code: b9 04 00 00 4c 8b 43 40 49 83 e8 18 49 8d 78 18 48 39 fd 0f 84 d0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 e3 04 00 00 49 bd 00 00 00 00 00 fc ff df 4d 8b
RSP: 0018:ffffc90001677c20 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffff8880a6081120 RCX: 1ffffffff1517002
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: ffff8880a6081160 R08: ffffffffffffffe8 R09: ffffc90001677cb8
R10: 0000000000000003 R11: fffff520002cef7e R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000
FS: 000000000136f880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000140 CR3: 00000000936b4000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this bug, for details see:
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[Jens Axboe]

I think this will likely fix it.


diff --git a/fs/io_uring.c b/fs/io_uring.c
index 70ae7e840c85..79c90eb28c0d 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -924,6 +924,7 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
goto err;

ctx->flags = p->flags;
+ init_waitqueue_head(&ctx->sqo_wait);
init_waitqueue_head(&ctx->cq_wait);
INIT_LIST_HEAD(&ctx->cq_overflow_list);
init_completion(&ctx->completions[0]);
@@ -6837,7 +6838,6 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx,
{
int ret;

- init_waitqueue_head(&ctx->sqo_wait);
mmgrab(current->mm);
ctx->sqo_mm = current->mm;


--
Jens Axboe