[syzbot] [block?] [bcachefs?] kernel panic: KASAN: panic_on_warn set ...

[syzbot] [block?] [bcachefs?] kernel panic: KASAN: panic_on_warn set ...

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    3088d26962e8 Merge tag 'x86-urgent-2025-04-18' of git://gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17aed470580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2a31f7155996562
dashboard link: https://syzkaller.appspot.com/bug?extid=4eb503ec2b8156835f24
compiler:       Debian clang version 15.0.6, Debian LLD 15.0.6

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-3088d269.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5ec84510bfc9/vmlinux-3088d269.xz
kernel image: https://storage.googleapis.com/syzbot-assets/af58d0bee0a4/bzImage-3088d269.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4eb503ec2b8156835f24@syzkaller.appspotmail.com

Kernel panic - not syncing: KASAN: panic_on_warn set ...
CPU: 0 UID: 0 PID: 47 Comm: kworker/u4:3 Not tainted 6.15.0-rc2-syzkaller-00400-g3088d26962e8 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: loop0 loop_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 panic+0x349/0x880 kernel/panic.c:354
 check_panic_on_warn+0x86/0xb0 kernel/panic.c:243
 end_report+0x77/0x160 mm/kasan/report.c:227
 kasan_report+0x154/0x180 mm/kasan/report.c:636
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x28f/0x2a0 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
 put_bh include/linux/buffer_head.h:301 [inline]
 end_buffer_read_sync+0xc1/0xd0 fs/buffer.c:161
 end_bio_bh_io_sync+0xbf/0x120 fs/buffer.c:2748
 blk_update_request+0x5e5/0x1160 block/blk-mq.c:983
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1145
 lo_rw_aio_do_completion drivers/block/loop.c:317 [inline]
 lo_rw_aio_complete drivers/block/loop.c:325 [inline]
 lo_rw_aio+0xdfd/0xf80 drivers/block/loop.c:398
 do_req_filebacked drivers/block/loop.c:-1 [inline]
 loop_handle_cmd drivers/block/loop.c:1866 [inline]
 loop_process_work+0x8e3/0x11f0 drivers/block/loop.c:1901
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [block?] [bcachefs?] kernel panic: KASAN: panic_on_warn set ...

[Kent Overstreet]

I'm not sure which subsystem this is, but it's definitely not bcachefs -
we don't use buffer heads.

On Sat, Apr 19, 2025 at 01:36:20AM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    3088d26962e8 Merge tag 'x86-urgent-2025-04-18' of git://gi..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17aed470580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2a31f7155996562
> dashboard link: https://syzkaller.appspot.com/bug?extid=4eb503ec2b8156835f24
> compiler:       Debian clang version 15.0.6, Debian LLD 15.0.6
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-3088d269.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/5ec84510bfc9/vmlinux-3088d269.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/af58d0bee0a4/bzImage-3088d269.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+4eb503ec2b8156835f24@syzkaller.appspotmail.com
> 
> Kernel panic - not syncing: KASAN: panic_on_warn set ...
> CPU: 0 UID: 0 PID: 47 Comm: kworker/u4:3 Not tainted 6.15.0-rc2-syzkaller-00400-g3088d26962e8 #0 PREEMPT(full) 
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
> Workqueue: loop0 loop_workfn
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:94 [inline]
>  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
>  panic+0x349/0x880 kernel/panic.c:354
>  check_panic_on_warn+0x86/0xb0 kernel/panic.c:243
>  end_report+0x77/0x160 mm/kasan/report.c:227
>  kasan_report+0x154/0x180 mm/kasan/report.c:636
>  check_region_inline mm/kasan/generic.c:-1 [inline]
>  kasan_check_range+0x28f/0x2a0 mm/kasan/generic.c:189
>  instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
>  atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
>  put_bh include/linux/buffer_head.h:301 [inline]
>  end_buffer_read_sync+0xc1/0xd0 fs/buffer.c:161
>  end_bio_bh_io_sync+0xbf/0x120 fs/buffer.c:2748
>  blk_update_request+0x5e5/0x1160 block/blk-mq.c:983
>  blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1145
>  lo_rw_aio_do_completion drivers/block/loop.c:317 [inline]
>  lo_rw_aio_complete drivers/block/loop.c:325 [inline]
>  lo_rw_aio+0xdfd/0xf80 drivers/block/loop.c:398
>  do_req_filebacked drivers/block/loop.c:-1 [inline]
>  loop_handle_cmd drivers/block/loop.c:1866 [inline]
>  loop_process_work+0x8e3/0x11f0 drivers/block/loop.c:1901
>  process_one_work kernel/workqueue.c:3238 [inline]
>  process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
>  worker_thread+0x870/0xd50 kernel/workqueue.c:3400
>  kthread+0x7b7/0x940 kernel/kthread.c:464
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
> 
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
> 
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
> 
> If you want to undo deduplication, reply with:
> #syz undup

Re: [syzbot] [block?] [bcachefs?] kernel panic: KASAN: panic_on_warn set ...

[Kent Overstreet]

On Sat, Apr 19, 2025 at 08:23:50AM -0400, Kent Overstreet wrote:
> I'm not sure which subsystem this is, but it's definitely not bcachefs -
> we don't use buffer heads.

I think there's some incorrect deduplication going on with this bug,
some of the reports do not look closely related, I believe they're all
buffer heads related.

#syz set-subsystems: block fs

Re: [syzbot] [block?] [bcachefs?] kernel panic: KASAN: panic_on_warn set ...

[syzbot]

> On Sat, Apr 19, 2025 at 08:23:50AM -0400, Kent Overstreet wrote:
>> I'm not sure which subsystem this is, but it's definitely not bcachefs -
>> we don't use buffer heads.
>
> I think there's some incorrect deduplication going on with this bug,
> some of the reports do not look closely related, I believe they're all
> buffer heads related.
>
> #syz set-subsystems: block fs

unknown command "set-subsystems:"