linux-kernel - [syzbot] [gfs2?] general protection fault in gfs2_thaw_freeze

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Message-ID: <68f6a505.050a0220.91a22.0455.GAE@google.com>
Date: Mon, 20 Oct 2025 14:09:25 -0700
From: syzbot <syzbot+18b8ec796f5bcc9ea482@...kaller.appspotmail.com>
To: agruenba@...hat.com, gfs2@...ts.linux.dev, linux-kernel@...r.kernel.org, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [gfs2?] general protection fault in gfs2_thaw_freeze_initiator

Hello,

syzbot found the following issue on:

HEAD commit:    606da5bb1655 Add linux-next specific files for 20251020
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15e57de2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cc275090905d8fd7
dashboard link: https://syzkaller.appspot.com/bug?extid=18b8ec796f5bcc9ea482
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=106a9492580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/dfd005041711/disk-606da5bb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c92ee475612c/vmlinux-606da5bb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/54c20315c52c/bzImage-606da5bb.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/802ab7289535/mount_2.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=11e57de2580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+18b8ec796f5bcc9ea482@...kaller.appspotmail.com

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)


---
This report is generated by a bot. It may contain errors.
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