syzbot


kernel BUG in do_xmote

Status: upstream: reported C repro on 2025/10/15 02:00
Subsystems: gfs2
[Documentation on labels]
Reported-by: syzbot+353de08f32ce69361b89@syzkaller.appspotmail.com
First crash: 93d, last: 73d
Cause bisection: introduced by (bisect log) :
commit 669d4eb0b91817f2451a0210c79ef4c21af66f49
Author: Andreas Gruenbacher <agruenba@redhat.com>
Date: Mon Aug 4 22:07:02 2025 +0000

  gfs2: Clean up properly during a withdraw

Crash: kernel BUG in do_xmote (log)
Repro: C syz .config
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] gfs2: Fix invalid glock target state during withdraw 1 (1) 2025/11/01 15:35
[syzbot] [gfs2?] kernel BUG in do_xmote 0 (3) 2025/10/22 22:32
Last patch testing requests (5)
Created Duration User Patch Repo Result
2026/01/06 17:38 3h23m retest repro linux-next OK log
2026/01/06 17:38 3h15m retest repro linux-next report log
2025/10/28 14:18 18m retest repro linux-next report log
2025/10/28 14:18 17m retest repro linux-next report log
2025/10/22 22:32 22m agruenba@redhat.com https://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2.git for-next report log
Cause bisection attempts (2)
Created Duration User Patch Repo Result
2025/10/21 15:11 10h59m bisect linux-next OK (1) job log log
2025/10/14 05:49 6h45m bisect linux-next error job log

Sample crash report:
gfs2: fsid=syz:syz.0: G:  s:EX n:3/2090 f:lyfaqo t:EX d:EX/0 a:0 v:0 r:3 m:20 p:0
gfs2: fsid=syz:syz.0:  H: s:EX f:nW e:0 p:6071 [syz.0.20] gfs2_iomap_begin_write fs/gfs2/bmap.c:1040 [inline]
gfs2: fsid=syz:syz.0:  H: s:EX f:nW e:0 p:6071 [syz.0.20] gfs2_iomap_begin+0x7a3/0x11c0 fs/gfs2/bmap.c:1133
gfs2: fsid=syz:syz.0:  R: n:8336 f:80000000 b:826/826 i:7 q:810 r:0 e:7001
gfs2: fsid=syz:syz.0:   B: n:9394 s:15569 f:810
------------[ cut here ]------------
kernel BUG at fs/gfs2/glock.c:674!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 95 Comm: kworker/1:1H Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: gfs2-glock/syz:syz glock_work_func
RIP: 0010:do_xmote+0x706/0x750 fs/gfs2/glock.c:674
Code: 38 c1 0f 8c a9 fe ff ff 48 89 df e8 64 77 29 fe e9 9c fe ff ff e8 ea cd c3 fd 31 ff 48 89 de ba 01 00 00 00 e8 1b e9 fe ff 90 <0f> 0b e8 d3 cd c3 fd 31 ff 48 89 de ba 01 00 00 00 e8 04 e9 fe ff
RSP: 0018:ffffc9000212f9a0 EFLAGS: 00010246
RAX: 992e81f959216400 RBX: ffff88805a6b2bc0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: ffffffff8bb183c0 R08: ffff88807b7b687b R09: 1ffff1100f6f6d0f
R10: dffffc0000000000 R11: ffffed100f6f6d10 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000015
FS:  0000000000000000(0000) GS:ffff888125e08000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000609000 CR3: 000000007897a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 glock_work_func+0x2a8/0x580 fs/gfs2/glock.c:1002
 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:do_xmote+0x706/0x750 fs/gfs2/glock.c:674
Code: 38 c1 0f 8c a9 fe ff ff 48 89 df e8 64 77 29 fe e9 9c fe ff ff e8 ea cd c3 fd 31 ff 48 89 de ba 01 00 00 00 e8 1b e9 fe ff 90 <0f> 0b e8 d3 cd c3 fd 31 ff 48 89 de ba 01 00 00 00 e8 04 e9 fe ff
RSP: 0018:ffffc9000212f9a0 EFLAGS: 00010246
RAX: 992e81f959216400 RBX: ffff88805a6b2bc0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: ffffffff8bb183c0 R08: ffff88807b7b687b R09: 1ffff1100f6f6d0f
R10: dffffc0000000000 R11: ffffed100f6f6d10 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000015
FS:  0000000000000000(0000) GS:ffff888125e08000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000609000 CR3: 000000007897a000 CR4: 00000000003526f0

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/14 05:29 linux-next 52ba76324a9d b6605ba8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root kernel BUG in do_xmote
2025/11/02 23:35 linux-next 98bd8b16ae57 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root kernel BUG in do_xmote
2025/10/14 12:14 linux-next 52ba76324a9d b6605ba8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root kernel BUG in do_xmote
2025/10/13 12:59 linux-next 52ba76324a9d ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root kernel BUG in do_xmote
* Struck through repros no longer work on HEAD.