syzbot


BUG: unable to handle kernel paging request in bch2_dev_do_discards

Status: moderation: reported on 2025/02/10 17:37
Subsystems: bcachefs
[Documentation on labels]
Reported-by: syzbot+8dd2ec793a816ee91fb2@syzkaller.appspotmail.com
First crash: 13d, last: 13d

Sample crash report:
Unable to handle kernel paging request at virtual address 00195f4c001fffe3
Mem abort info:
  ESR = 0x0000000096000004
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x04: level 0 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[00195f4c001fffe3] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 UID: 0 PID: 6453 Comm: kworker/u9:5 Not tainted 6.14.0-rc1-syzkaller-g2014c95afece #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: bcachefs_journal journal_write_done
pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __lock_acquire+0xfc/0x7904 kernel/locking/lockdep.c:5091
lr : lock_acquire+0x23c/0x724 kernel/locking/lockdep.c:5851
sp : ffff8000a3aa7260
x29: ffff8000a3aa7520 x28: ffff80008036466c x27: 0000000000000000
x26: ffff0001b37b2540 x25: 0000000000000000 x24: 0000000000000001
x23: 0000000000000000 x22: 1ffff00011f7a0cb x21: 00cefa6000ffff18
x20: 0000000000000001 x19: 0000000000000000 x18: ffff8000a3aa73e0
x17: 00000000000257b0 x16: ffff8000832d977c x15: 0000000000000001
x14: 1fffe000366f45d0 x13: dfff800000000000 x12: ffff700014754e74
x11: ffff80008046d80c x10: ffff80008fbd0658 x9 : 00000000000000f3
x8 : 0019df4c001fffe3 x7 : ffff80008036466c x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000000000000 x0 : 00cefa6000ffff18
Call trace:
 __lock_acquire+0xfc/0x7904 kernel/locking/lockdep.c:5091 (P)
 lock_acquire+0x23c/0x724 kernel/locking/lockdep.c:5851
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x48/0x60 kernel/locking/spinlock.c:154
 __queue_work+0x8b0/0x1308
 queue_work_on+0xe0/0x1a0 kernel/workqueue.c:2390
 queue_work include/linux/workqueue.h:662 [inline]
 bch2_dev_do_discards+0x14c/0x2d4 fs/bcachefs/alloc_background.c:1949
 bch2_do_discards+0x34/0x6c fs/bcachefs/alloc_background.c:1960
 journal_write_done+0x5bc/0xba4 fs/bcachefs/journal_io.c:1657
 process_one_work+0x7a8/0x15cc kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3317 [inline]
 worker_thread+0x97c/0xeec kernel/workqueue.c:3398
 kthread+0x65c/0x7b0 kernel/kthread.c:464
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862
Code: f007bb08 b9465908 340090a8 d343fea8 (386d6908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	f007bb08 	adrp	x8, 0xf763000
   4:	b9465908 	ldr	w8, [x8, #1624]
   8:	340090a8 	cbz	w8, 0x121c
   c:	d343fea8 	lsr	x8, x21, #3
* 10:	386d6908 	ldrb	w8, [x8, x13] <-- trapping instruction

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/07 20:21 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2014c95afece a4f327c2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in bch2_dev_do_discards
* Struck through repros no longer work on HEAD.