syzbot


general protection fault in gfs2_glock_dq (2)

Status: upstream: reported on 2025/12/26 11:22
Subsystems: gfs2
[Documentation on labels]
Reported-by: syzbot+5a5f492ccae698fd7434@syzkaller.appspotmail.com
First crash: 35d, last: 1d01h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [gfs2?] general protection fault in gfs2_glock_dq (2) 0 (1) 2025/12/26 11:22
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in gfs2_glock_dq gfs2 2 16 303d 425d 0/29 auto-obsoleted due to no activity on 2025/06/21 04:26
linux-6.1 BUG: unable to handle kernel paging request in gfs2_glock_dq 8 6 173d 173d 0/3 auto-obsoleted due to no activity on 2025/10/29 04:50

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
CPU: 0 UID: 0 PID: 5345 Comm: syz.0.0 Not tainted syzkaller #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
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 c0 e3 35 09 cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc9000ccdfb68 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffffff8b5e361e RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8b5e361e RDI: 0000000000000007
RBP: ffffffff8400f750 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100844f748 R12: 0000000000000000
R13: 0000000000000038 R14: 0000000000000038 R15: 0000000000000001
FS:  00007fc4b75556c0(0000) GS:ffff88808d414000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc4b7554fc8 CR3: 0000000043f17000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __kasan_check_byte+0x12/0x40 mm/kasan/common.c:573
 kasan_check_byte include/linux/kasan.h:402 [inline]
 lock_acquire+0x84/0x340 kernel/locking/lockdep.c:5842
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 gfs2_glock_dq+0x50/0x7c0 fs/gfs2/glock.c:1577
 gfs2_glock_dq_uninit+0x25/0xb0 fs/gfs2/glock.c:1623
 gfs2_seek_hole+0x16c/0x240 fs/gfs2/inode.c:2237
 gfs2_llseek+0xfa/0x240 fs/gfs2/file.c:79
 vfs_llseek fs/read_write.c:389 [inline]
 ksys_lseek fs/read_write.c:402 [inline]
 __do_sys_lseek fs/read_write.c:412 [inline]
 __se_sys_lseek fs/read_write.c:410 [inline]
 __x64_sys_lseek+0x14f/0x1e0 fs/read_write.c:410
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc4b678f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc4b7555038 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
RAX: ffffffffffffffda RBX: 00007fc4b69e6090 RCX: 00007fc4b678f7c9
RDX: 0000000000000004 RSI: ffffffffffffffff RDI: 0000000000000005
RBP: 00007fc4b6813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc4b69e6128 R14: 00007fc4b69e6090 R15: 00007ffd46a8cbe8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 c0 e3 35 09 cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc9000ccdfb68 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffffff8b5e361e RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8b5e361e RDI: 0000000000000007
RBP: ffffffff8400f750 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100844f748 R12: 0000000000000000
R13: 0000000000000038 R14: 0000000000000038 R15: 0000000000000001
FS:  00007fc4b75556c0(0000) GS:ffff88808d414000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc4b7554fc8 CR3: 0000000043f17000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
   7:	00
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	0f 1f 40 d6          	nopl   -0x2a(%rax)
  1c:	48 c1 ef 03          	shr    $0x3,%rdi
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	0f b6 04 07          	movzbl (%rdi,%rax,1),%eax <-- trapping instruction
  2e:	3c 08                	cmp    $0x8,%al
  30:	0f 92 c0             	setb   %al
  33:	e9 c0 e3 35 09       	jmp    0x935e3f8
  38:	cc                   	int3
  39:	66                   	data16
  3a:	66                   	data16
  3b:	66                   	data16
  3c:	66                   	data16
  3d:	66                   	data16
  3e:	66                   	data16
  3f:	2e                   	cs

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/09 09:28 upstream 54e82e93ca93 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in gfs2_glock_dq
2026/01/09 08:38 upstream 54e82e93ca93 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in gfs2_glock_dq
2025/12/26 11:21 upstream ccd1cdca5cd4 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in gfs2_glock_dq
2025/12/19 10:48 upstream 516471569089 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in gfs2_glock_dq
2025/12/15 07:12 upstream 8f0b4cce4481 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in gfs2_glock_dq
2025/12/08 17:28 upstream c2f2b01b74be d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in gfs2_glock_dq
2025/12/06 00:27 upstream d1d36025a617 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in gfs2_glock_dq
2025/12/28 15:30 linux-next cc3aa43b44bd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in gfs2_glock_dq
* Struck through repros no longer work on HEAD.