[syzbot] BUG: unable to handle kernel paging request in corrupted (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    88b06399 Merge tag 'for-5.13-rc1-part2-tag' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11aa7a65d00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=807beec6b4d66bf1
dashboard link: https://syzkaller.appspot.com/bug?extid=a84b8783366ecb1c65d0
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16a031b3d00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12fc54fdd00000

The issue was bisected to:

commit ea6a693d862d4f0edd748a1fa3fc6faf2c39afb2
Author: Jens Axboe <axboe@xxxxxxxxx>
Date:   Thu Apr 15 15:47:13 2021 +0000

    io_uring: disable multishot poll for double poll add cases

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=104b5795d00000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=124b5795d00000
console output: https://syzkaller.appspot.com/x/log.txt?x=144b5795d00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a84b8783366ecb1c65d0@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: ea6a693d862d ("io_uring: disable multishot poll for double poll add cases")

BUG: unable to handle page fault for address: ffffffffc1defce0
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD bc8f067 P4D bc8f067 PUD bc91067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8479 Comm: iou-wrk-8440 Not tainted 5.13.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0xffffffffc1defce0
Code: Unable to access opcode bytes at RIP 0xffffffffc1defcb6.
RSP: 0018:ffffc9000161f8f8 EFLAGS: 00010246
RAX: ffffffffc1defce0 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880187eb8c0
RBP: ffff8880187eb8c0 R08: 0000000000000000 R09: 0000000000002000
R10: ffffffff81df1723 R11: 0000000000004000 R12: 0000000000000000
R13: ffff8880187eb918 R14: ffff8880187eb900 R15: ffffffffc1defce0
FS:  0000000001212300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc1defcb6 CR3: 00000000139d9000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
Modules linked in:
CR2: ffffffffc1defce0
---[ end trace a41da77ef833bc79 ]---
RIP: 0010:0xffffffffc1defce0
Code: Unable to access opcode bytes at RIP 0xffffffffc1defcb6.
RSP: 0018:ffffc9000161f8f8 EFLAGS: 00010246
RAX: ffffffffc1defce0 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880187eb8c0
RBP: ffff8880187eb8c0 R08: 0000000000000000 R09: 0000000000002000
R10: ffffffff81df1723 R11: 0000000000004000 R12: 0000000000000000
R13: ffff8880187eb918 R14: ffff8880187eb900 R15: ffffffffc1defce0
FS:  0000000001212300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc1defcb6 CR3: 00000000139d9000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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