syzbot


stack segment fault in gfs2_glock_dq

Status: upstream: reported C repro on 2025/05/01 19:08
Subsystems: gfs2
[Documentation on labels]
Reported-by: syzbot+e0dbe53de58ffe4a5f31@syzkaller.appspotmail.com
First crash: 105d, last: 20d
Discussions (3)
Title Replies (including bot) Last reply
[syzbot] Monthly gfs2 report (Jun 2025) 0 (1) 2025/06/13 12:25
[syzbot] Monthly gfs2 report (May 2025) 0 (1) 2025/05/12 13:34
[syzbot] [gfs2?] stack segment fault in gfs2_glock_dq 0 (1) 2025/05/01 19:08
Last patch testing requests (2)
Created Duration User Patch Repo Result
2025/08/09 04:02 21m retest repro upstream OK log
2025/05/31 03:35 14m retest repro upstream report log

Sample crash report:
Oops: stack segment: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5343 Comm: syz.0.0 Not tainted 6.16.0-rc7-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:gfs2_glock_dq+0x60/0xb20 fs/gfs2/glock.c:1656
Code: 4c 89 ff e8 22 a6 32 fe 4c 89 64 24 28 4c 89 7c 24 30 4d 8b 2f 4d 8d 7d 10 4c 89 fd 48 c1 ed 03 48 b8 00 00 00 00 00 fc ff df <80> 7c 05 00 00 74 08 4c 89 ff e8 f1 a5 32 fe 49 8b 45 10 48 89 44
RSP: 0018:ffffc9000d46fc20 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000100000
RDX: ffffc9000f164000 RSI: 00000000000000ac RDI: 00000000000000ad
RBP: 0000000000000002 R08: ffff888052f774f3 R09: 1ffff1100a5eee9e
R10: dffffc0000000000 R11: ffffed100a5eee9f R12: 1ffff92001a8dfa2
R13: 0000000000000000 R14: ffffc9000d46fd00 R15: 0000000000000010
FS:  00007f87d86066c0(0000) GS:ffff88808d218000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000006b6c00 CR3: 0000000040f1e000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 gfs2_glock_dq_uninit+0x25/0xb0 fs/gfs2/glock.c:1722
 gfs2_seek_data+0x16c/0x240 fs/gfs2/inode.c:2214
 gfs2_llseek+0x1a4/0x240 fs/gfs2/file.c:75
 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+0x14c/0x1e0 fs/read_write.c:410
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f87d778e9a9
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:00007f87d8606038 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
RAX: ffffffffffffffda RBX: 00007f87d79b6160 RCX: 00007f87d778e9a9
RDX: 0000000000000003 RSI: 0000000000000008 RDI: 0000000000000004
RBP: 00007f87d7810d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f87d79b6160 R15: 00007ffce547f4b8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:gfs2_glock_dq+0x60/0xb20 fs/gfs2/glock.c:1656
Code: 4c 89 ff e8 22 a6 32 fe 4c 89 64 24 28 4c 89 7c 24 30 4d 8b 2f 4d 8d 7d 10 4c 89 fd 48 c1 ed 03 48 b8 00 00 00 00 00 fc ff df <80> 7c 05 00 00 74 08 4c 89 ff e8 f1 a5 32 fe 49 8b 45 10 48 89 44
RSP: 0018:ffffc9000d46fc20 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000100000
RDX: ffffc9000f164000 RSI: 00000000000000ac RDI: 00000000000000ad
RBP: 0000000000000002 R08: ffff888052f774f3 R09: 1ffff1100a5eee9e
R10: dffffc0000000000 R11: ffffed100a5eee9f R12: 1ffff92001a8dfa2
R13: 0000000000000000 R14: ffffc9000d46fd00 R15: 0000000000000010
FS:  00007f87d86066c0(0000) GS:ffff88808d218000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055eb3f12c770 CR3: 0000000040f1e000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	4c 89 ff             	mov    %r15,%rdi
   3:	e8 22 a6 32 fe       	call   0xfe32a62a
   8:	4c 89 64 24 28       	mov    %r12,0x28(%rsp)
   d:	4c 89 7c 24 30       	mov    %r15,0x30(%rsp)
  12:	4d 8b 2f             	mov    (%r15),%r13
  15:	4d 8d 7d 10          	lea    0x10(%r13),%r15
  19:	4c 89 fd             	mov    %r15,%rbp
  1c:	48 c1 ed 03          	shr    $0x3,%rbp
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	80 7c 05 00 00       	cmpb   $0x0,0x0(%rbp,%rax,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 ff             	mov    %r15,%rdi
  34:	e8 f1 a5 32 fe       	call   0xfe32a62a
  39:	49 8b 45 10          	mov    0x10(%r13),%rax
  3d:	48                   	rex.W
  3e:	89                   	.byte 0x89
  3f:	44                   	rex.R

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/22 03:46 upstream 89be9a83ccf1 1555463b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root stack segment fault in gfs2_glock_dq
2025/07/16 22:37 upstream 155a3c003e55 44f8051e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root stack segment fault in gfs2_glock_dq
2025/07/15 16:26 upstream 155a3c003e55 03fcfc4b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root stack segment fault in gfs2_glock_dq
2025/06/13 19:58 upstream 27605c8c0f69 1f72c409 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root stack segment fault in gfs2_glock_dq
2025/06/04 07:32 upstream 5abc7438f1e9 a30356b7 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root stack segment fault in gfs2_glock_dq
2025/06/03 15:28 upstream 546b1c9e93c2 a30356b7 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root stack segment fault in gfs2_glock_dq
2025/05/17 03:28 upstream 3c21441eeffc cfde8269 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root stack segment fault in gfs2_glock_dq
2025/05/04 05:28 upstream 2a239ffbebb5 b0714e37 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root stack segment fault in gfs2_glock_dq
2025/04/27 22:10 upstream 5bc1018675ec c6b4fb39 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci-snapshot-upstream-root stack segment fault in gfs2_glock_dq
2025/04/27 19:05 upstream 5bc1018675ec c6b4fb39 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root stack segment fault in gfs2_glock_dq
* Struck through repros no longer work on HEAD.