linux-kernel - [syzbot ci] Re: io_uring: make overflowing cqe subject to OOM

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Message-ID: <69537c0c.050a0220.329c0f.04b2.GAE@google.com>
Date: Mon, 29 Dec 2025 23:15:24 -0800
From: syzbot ci <syzbot+ci34ed6dfe453ba6f8@...kaller.appspotmail.com>
To: alexandre@...rel.dev, axboe@...nel.dk, io-uring@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Cc: syzbot@...ts.linux.dev, syzkaller-bugs@...glegroups.com
Subject: [syzbot ci] Re: io_uring: make overflowing cqe subject to OOM

syzbot ci has tested the following series

[v1] io_uring: make overflowing cqe subject to OOM
https://lore.kernel.org/all/20251229201933.515797-1-alexandre@negrel.dev
* [PATCH] io_uring: make overflowing cqe subject to OOM

and found the following issue:
WARNING in io_get_cqe_overflow

Full report is available here:
https://ci.syzbot.org/series/d71ff874-04e1-4cc7-b7c0-e48eb77bc984

***

WARNING in io_get_cqe_overflow

tree:      torvalds
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base:      f8f9c1f4d0c7a64600e2ca312dec824a0bc2f1da
arch:      amd64
compiler:  Debian clang version 21.1.8 (++20251202083448+f68f64eb8130-1~exp1~20251202083504.46), Debian LLD 21.1.8
config:    https://ci.syzbot.org/builds/c13ff885-4e87-4df2-9d49-a52f3d040dd6/config
C repro:   https://ci.syzbot.org/findings/e3c6e33b-4e4e-45de-b5b7-4ff5fc363989/c_repro
syz repro: https://ci.syzbot.org/findings/e3c6e33b-4e4e-45de-b5b7-4ff5fc363989/syz_repro

------------[ cut here ]------------
WARNING: io_uring/io_uring.h:211 at io_lockdep_assert_cq_locked io_uring/io_uring.h:211 [inline], CPU#0: syz.0.17/5984
WARNING: io_uring/io_uring.h:211 at io_get_cqe_overflow+0x599/0x730 io_uring/io_uring.h:249, CPU#0: syz.0.17/5984
Modules linked in:
CPU: 0 UID: 0 PID: 5984 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:io_lockdep_assert_cq_locked io_uring/io_uring.h:211 [inline]
RIP: 0010:io_get_cqe_overflow+0x599/0x730 io_uring/io_uring.h:249
Code: 0f 0b 90 e9 0e fb ff ff e8 c4 29 35 fd 90 0f 0b 90 e9 91 fb ff ff e8 b6 29 35 fd 90 0f 0b 90 e9 6a fd ff ff e8 a8 29 35 fd 90 <0f> 0b 90 e9 5c fd ff ff e8 9a 29 35 fd 90 0f 0b 90 e9 4a fd ff ff
RSP: 0018:ffffc90003cf7958 EFLAGS: 00010293
RAX: ffffffff848d4748 RBX: 0000000000000000 RCX: ffff888110c8ba80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff888110c8ba80 R09: 0000000000000002
R10: 00000000fffffdef R11: 0000000000000000 R12: 0000000000000000
R13: 1ffff11022544c00 R14: ffff888112a26000 R15: dffffc0000000000
FS:  00005555940b9500(0000) GS:ffff88818e40f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30563fff CR3: 00000001731de000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 io_get_cqe io_uring/io_uring.h:271 [inline]
 io_fill_cqe_req io_uring/io_uring.h:293 [inline]
 __io_submit_flush_completions+0x11c/0xe50 io_uring/io_uring.c:1507
 io_submit_flush_completions io_uring/io_uring.h:239 [inline]
 io_submit_state_end io_uring/io_uring.c:2318 [inline]
 io_submit_sqes+0x1c26/0x2130 io_uring/io_uring.c:2433
 __do_sys_io_uring_enter io_uring/io_uring.c:3264 [inline]
 __se_sys_io_uring_enter+0x2f7/0x2c30 io_uring/io_uring.c:3203
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f00d579acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc380f6178 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f00d5a05fa0 RCX: 00007f00d579acb9
RDX: 0000000000000002 RSI: 0000000000004d10 RDI: 0000000000000003
RBP: 00007f00d5808bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f00d5a05fac R14: 00007f00d5a05fa0 R15: 00007f00d5a05fa0
 </TASK>


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@...kaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@...glegroups.com.