syzbot


BUG: unable to handle kernel NULL pointer dereference in fuse_dev_release

Status: auto-obsoleted due to no activity on 2023/04/05 16:12
Subsystems: fuse
[Documentation on labels]
Reported-by: syzbot+7f8d6161254f65339fbb@syzkaller.appspotmail.com
First crash: 474d, last: 474d

Sample crash report:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
Mem abort info:
  ESR = 0x0000000096000046
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000046
  CM = 0, WnR = 1
user pgtable: 4k pages, 48-bit VAs, pgdp=0000000143267000
[0000000000000008] pgd=0800000145203003, p4d=0800000145203003, pud=080000013eea4003, pmd=0000000000000000
Internal error: Oops: 0000000096000046 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 9886 Comm: syz-executor.3 Not tainted 6.1.0-rc2-syzkaller-154433-g247f34f7b803 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __list_splice include/linux/list.h:449 [inline]
pc : list_splice_init include/linux/list.h:491 [inline]
pc : fuse_dev_release+0x90/0x24c fs/fuse/dev.c:2207
lr : list_splice_init include/linux/list.h:491 [inline]
lr : fuse_dev_release+0x88/0x24c fs/fuse/dev.c:2207
sp : ffff800016a6bce0
x29: ffff800016a6bd00 x28: 00000000000e001b x27: 0000000000002000
x26: ffff0000c1697af8 x25: 0000000000000000 x24: ffff000103124ff0
x23: ffff800016a6bce8 x22: 0000000000000ff0 x21: ffff0000fed7e210
x20: ffff0000fe2f0400 x19: ffff0000fed7e200 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000003 x12: ffff80000d3bb3b0
x11: ff80800008cd572c x10: 0000000000000000 x9 : 0000000000000000
x8 : ffff0000fe939340 x7 : 0000000000000000 x6 : ffff800008cd56f8
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 __list_splice include/linux/list.h:447 [inline]
 list_splice_init include/linux/list.h:491 [inline]
 fuse_dev_release+0x90/0x24c fs/fuse/dev.c:2207
 __fput+0x198/0x3e4 fs/file_table.c:320
 ____fput+0x20/0x30 fs/file_table.c:348
 task_work_run+0x100/0x148 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
Code: 540001a0 97d7467a f94007e8 f9400709 (f9000737) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	540001a0 	b.eq	0x34  // b.none
   4:	97d7467a 	bl	0xffffffffff5d19ec
   8:	f94007e8 	ldr	x8, [sp, #8]
   c:	f9400709 	ldr	x9, [x24, #8]
* 10:	f9000737 	str	x23, [x25, #8] <-- trapping instruction

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/01/05 16:11 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 247f34f7b803 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel NULL pointer dereference in fuse_dev_release
* Struck through repros no longer work on HEAD.