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+4eb503ec2b8156835...@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 syzkal...@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
