syzbot


general protection fault in gfs2_thaw_freeze_initiator

Status: upstream: reported syz repro on 2025/10/20 21:09
Subsystems: gfs2
[Documentation on labels]
Reported-by: syzbot+18b8ec796f5bcc9ea482@syzkaller.appspotmail.com
First crash: 1d21h, last: 1d21h
Discussions (1)
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[syzbot] [gfs2?] general protection fault in gfs2_thaw_freeze_initiator 0 (1) 2025/10/20 21:09

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000206: 0000 [#1] SMP KASAN PTI
KASAN: probably user-memory-access in range [0x0000000000001030-0x0000000000001037]
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events gfs2_withdraw_func
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:577 [inline]
RIP: 0010:__mutex_lock+0x13b/0x1350 kernel/locking/mutex.c:760
Code: 80 63 9d 99 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 2b 10 00 00 83 3d 43 45 4d 0e 00 75 23 49 8d 7c 24 60 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 f9 03 d6 f6 4d 39 64 24 60 0f 85 51 0f 00
RSP: 0018:ffffc900000f7720 EFLAGS: 00010206
RAX: 0000000000000206 RBX: ffffc900000f7800 RCX: ffffffff999d6303
RDX: ffff88801ce89e40 RSI: ffffffff8da16ac7 RDI: 0000000000001030
RBP: ffffc900000f78c8 R08: ffffc900000f7847 R09: 0000000000000000
R10: ffffc900000f7820 R11: fffff5200001ef09 R12: 0000000000000fd0
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125cfe000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f09ea358000 CR3: 00000000292f8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 gfs2_thaw_freeze_initiator+0x4e/0xc0 fs/gfs2/super.c:826
 do_withdraw+0x2bf/0x320 fs/gfs2/util.c:155
 gfs2_withdraw_func+0x2f3/0x430 fs/gfs2/util.c:-1
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:577 [inline]
RIP: 0010:__mutex_lock+0x13b/0x1350 kernel/locking/mutex.c:760
Code: 80 63 9d 99 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 2b 10 00 00 83 3d 43 45 4d 0e 00 75 23 49 8d 7c 24 60 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 f9 03 d6 f6 4d 39 64 24 60 0f 85 51 0f 00
RSP: 0018:ffffc900000f7720 EFLAGS: 00010206
RAX: 0000000000000206 RBX: ffffc900000f7800 RCX: ffffffff999d6303
RDX: ffff88801ce89e40 RSI: ffffffff8da16ac7 RDI: 0000000000001030
RBP: ffffc900000f78c8 R08: ffffc900000f7847 R09: 0000000000000000
R10: ffffc900000f7820 R11: fffff5200001ef09 R12: 0000000000000fd0
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125cfe000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f09ea358000 CR3: 00000000292f8000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	80 63 9d 99          	andb   $0x99,-0x63(%rbx)
   4:	48 c1 e8 03          	shr    $0x3,%rax
   8:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax
   d:	84 c0                	test   %al,%al
   f:	0f 85 2b 10 00 00    	jne    0x1040
  15:	83 3d 43 45 4d 0e 00 	cmpl   $0x0,0xe4d4543(%rip)        # 0xe4d455f
  1c:	75 23                	jne    0x41
  1e:	49 8d 7c 24 60       	lea    0x60(%r12),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 05                	je     0x36
  31:	e8 f9 03 d6 f6       	call   0xf6d6042f
  36:	4d 39 64 24 60       	cmp    %r12,0x60(%r12)
  3b:	0f                   	.byte 0xf
  3c:	85 51 0f             	test   %edx,0xf(%rcx)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/20 12:51 linux-next 606da5bb1655 1c8c8cd8 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root general protection fault in gfs2_thaw_freeze_initiator
* Struck through repros no longer work on HEAD.