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]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6aadf7fb.71f81b7d.15fa6d.0003.GAE@google.com \
--to=syzbot+ci95a1b00e6c96231b@syzkaller.appspotmail.com \
--cc=a.hindborg@kernel.org \
--cc=axboe@kernel.dk \
--cc=bvanassche@acm.org \
--cc=gary@garyguo.net \
--cc=hch@lst.de \
--cc=linux-block@vger.kernel.org \
--cc=nilay@linux.ibm.com \
--cc=ojeda@kernel.org \
--cc=penguin-kernel@i-love.sakura.ne.jp \
--cc=royenheart@gmail.com \
--cc=sunke@kylinos.cn \
--cc=syzbot@lists.linux.dev \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.