From: syzbot ci <syzbot+ci95a1b00e6c96231b@syzkaller.appspotmail.com>
To: a.hindborg@kernel.org, axboe@kernel.dk, bvanassche@acm.org,
gary@garyguo.net, hch@lst.de, linux-block@vger.kernel.org,
nilay@linux.ibm.com, ojeda@kernel.org,
penguin-kernel@i-love.sakura.ne.jp, royenheart@gmail.com,
sunke@kylinos.cn
Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com
Subject: [syzbot ci] Re: loop: Fix teardown
Date: Fri, 18 Sep 2026 19:48:27 -0700 [thread overview]
Message-ID: <6aadf7fb.71f81b7d.15fa6d.0003.GAE@google.com> (raw)
In-Reply-To: <cover.1789587960.git.bvanassche@acm.org>
syzbot ci has tested the following series
[v1] loop: Fix teardown
https://lore.kernel.org/all/cover.1789587960.git.bvanassche@acm.org
* [PATCH 1/2] block: Add post_release() operation
* [PATCH 2/2] loop: Perform __loop_clr_fd() after disk->open_mutex is dropped
and found the following issue:
general protection fault in lo_post_release
Full report is available here:
https://ci.syzbot.org/series/81bfb244-11b0-4b8a-aa02-a212681ff0af
***
general protection fault in lo_post_release
tree: axboe
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base: 2dd9768a37dbb99398c5e332485dbb107ac397c8
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/e21a78bb-e498-4518-8734-d31ae58a2538/config
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000a: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057]
CPU: 0 UID: 0 PID: 26297 Comm: udevd 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:lo_post_release+0x498/0x7f0
Code: 4c 89 ff e8 7a 73 f9 fb bf e0 01 00 00 49 03 3f be 02 00 00 00 e8 18 05 9e 05 48 8b 44 24 10 4c 8d 60 50 4c 89 e0 48 c1 e8 03 <42> 80 3c 30 00 74 08 4c 89 e7 e8 49 73 f9 fb 41 bf e8 00 00 00 4d
RSP: 0018:ffffc90003d6fb60 EFLAGS: 00010206
RAX: 000000000000000a RBX: ffff8881699b3000 RCX: 0000000000000046
RDX: 0000000000000006 RSI: ffffffff8e414976 RDI: ffffffff8c6da780
RBP: ffffc90003d6fd08 R08: ffffffff907a477f R09: 1ffffffff20f48ef
R10: dffffc0000000000 R11: fffffbfff20f48f0 R12: 0000000000000050
R13: 1ffff920007adf74 R14: dffffc0000000000 R15: ffff888169a02080
FS: 00007fa1afb46c80(0000) GS:ffff88818d6ce000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0d423a8440 CR3: 00000001bee1a000 CR4: 00000000000006f0
Call Trace:
<TASK>
bdev_release+0x59a/0x6b0
blkdev_release+0x15/0x20
__fput+0x418/0xa50
fput_close_sync+0x11f/0x240
__x64_sys_close+0x7e/0x110
do_syscall_64+0x166/0x520
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa1af7170a8
Code: 48 8b 05 83 9d 0d 00 64 c7 00 16 00 00 00 83 c8 ff 48 83 c4 20 5b c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 5b 48 8b 15 51 9d 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffeef68bbb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007fa1afb46ae0 RCX: 00007fa1af7170a8
RDX: 0000559097caaeb5 RSI: 00007ffeef68b3b8 RDI: 0000000000000008
RBP: 00005595ce9a3e90 R08: 0000000000000006 R09: a8cc15e7d6acaf3b
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000002
R13: 00005595ce999920 R14: 0000000000000008 R15: 00005595ce964910
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:lo_post_release+0x498/0x7f0
Code: 4c 89 ff e8 7a 73 f9 fb bf e0 01 00 00 49 03 3f be 02 00 00 00 e8 18 05 9e 05 48 8b 44 24 10 4c 8d 60 50 4c 89 e0 48 c1 e8 03 <42> 80 3c 30 00 74 08 4c 89 e7 e8 49 73 f9 fb 41 bf e8 00 00 00 4d
RSP: 0018:ffffc90003d6fb60 EFLAGS: 00010206
RAX: 000000000000000a RBX: ffff8881699b3000 RCX: 0000000000000046
RDX: 0000000000000006 RSI: ffffffff8e414976 RDI: ffffffff8c6da780
RBP: ffffc90003d6fd08 R08: ffffffff907a477f R09: 1ffffffff20f48ef
R10: dffffc0000000000 R11: fffffbfff20f48f0 R12: 0000000000000050
R13: 1ffff920007adf74 R14: dffffc0000000000 R15: ffff888169a02080
FS: 00007fa1afb46c80(0000) GS:ffff88818d6ce000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556cac6a68 CR3: 00000001bee1a000 CR4: 00000000000006f0
***
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@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.
To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.
Notes:
- The patch will be applied on top of the tested series (as an
incremental fix).
- To test a new version of the whole series, please send it directly
to syzbot@lists.linux.dev.
- Arguments like custom git repos and branches are not supported.
prev parent reply other threads:[~2026-09-19 2:48 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-16 19:51 [PATCH 0/2] loop: Fix teardown Bart Van Assche
2026-09-16 19:51 ` [PATCH 1/2] block: Add post_release() operation Bart Van Assche
2026-09-16 19:51 ` [PATCH 2/2] loop: Perform __loop_clr_fd() after disk->open_mutex is dropped Bart Van Assche
2026-09-16 22:47 ` Tetsuo Handa
2026-09-16 23:05 ` Bart Van Assche
2026-09-17 0:16 ` Tetsuo Handa
2026-09-19 2:48 ` syzbot ci [this message]
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