kernel BUG in ocfs2_write_begin_nolock (3)

Status: upstream: reported on 2026/08/28 02:12
Subsystems: ocfs2
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+fd44623201beb5f3b462@syzkaller.appspotmail.com
First crash: 5d09h, last: 5d09h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
f35a7971 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ kernel BUG in ocfs2_write_begin_nolock (3) 2026/08/26 00:38 2026/08/26 00:38 2026/08/26 01:20 ee98d2fd
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] kernel BUG in ocfs2_write_begin_nolock (3) 0 (1) 2026/08/28 02:12
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in ocfs2_write_begin_nolock (2) ocfs2 -1 7 316d 450d 0/29 auto-obsoleted due to no activity on 2026/01/25 00:47
upstream kernel BUG in ocfs2_write_begin_nolock ocfs2 -1 4 628d 651d 0/29 auto-obsoleted due to no activity on 2025/03/18 16:58

Sample crash report:
------------[ cut here ]------------
kernel BUG at fs/ocfs2/aops.c:1391!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 7883 Comm: syz.6.469 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:ocfs2_populate_write_desc fs/ocfs2/aops.c:1391 [inline]
RIP: 0010:ocfs2_write_begin_nolock+0x41b2/0x41f0 fs/ocfs2/aops.c:1689
Code: 84 3a e3 fd 49 bf 00 00 00 00 00 fc ff df 4c 8b 24 24 e9 62 fe ff ff e8 7c 50 fc 07 e8 67 3a e3 fd 90 0f 0b e8 5f 3a e3 fd 90 <0f> 0b e8 57 3a e3 fd 90 0f 0b e8 4f 3a e3 fd 90 0f 0b e8 47 3a e3
RSP: 0018:ffffc900060df2e0 EFLAGS: 00010293
RAX: ffffffff83e3f321 RBX: ffff88802a26c010 RCX: ffff88802ec5be80
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc900060df880 R08: ffff88802ec5be80 R09: 0000000000000006
R10: 00000000fffffffc R11: 0000000000000000 R12: ffff88802a26c000
R13: 1ffff110041ec81f R14: 0000000000000003 R15: 0000000000000000
FS:  0000555591908500(0000) GS:ffff888124cf3000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc5117ed158 CR3: 000000005a889000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 __ocfs2_page_mkwrite fs/ocfs2/mmap.c:92 [inline]
 ocfs2_page_mkwrite+0x640/0xb60 fs/ocfs2/mmap.c:143
 do_page_mkwrite+0x147/0x310 mm/memory.c:3754
 wp_page_shared mm/memory.c:4155 [inline]
 do_wp_page+0x1a9c/0x4b80 mm/memory.c:4378
 handle_pte_fault mm/memory.c:6520 [inline]
 __handle_mm_fault mm/memory.c:6645 [inline]
 handle_mm_fault+0x1576/0x3720 mm/memory.c:6814
 do_user_addr_fault+0x746/0x1340 arch/x86/mm/fault.c:1394
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f5f73c67682
Code: 30 48 8b 14 24 48 85 d2 74 17 8b 44 24 10 0f c8 89 c0 48 89 44 24 10 48 83 fa 01 0f 85 aa 02 00 00 48 8b 44 24 18 8b 74 24 10 <89> 30 e9 1e fe ff ff 48 8b 44 24 18 8b 10 48 8b 04 24 48 85 c0 0f
RSP: 002b:00007ffd7d7d31a0 EFLAGS: 00010246
RAX: 0000200000000180 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00005555919083d8
RBP: 00007ffd7d7d32c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00007ffd7d7d3300
R13: 00007f5f7402609c R14: 000000000002ae89 R15: 00007ffd7d7d32e0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ocfs2_populate_write_desc fs/ocfs2/aops.c:1391 [inline]
RIP: 0010:ocfs2_write_begin_nolock+0x41b2/0x41f0 fs/ocfs2/aops.c:1689
Code: 84 3a e3 fd 49 bf 00 00 00 00 00 fc ff df 4c 8b 24 24 e9 62 fe ff ff e8 7c 50 fc 07 e8 67 3a e3 fd 90 0f 0b e8 5f 3a e3 fd 90 <0f> 0b e8 57 3a e3 fd 90 0f 0b e8 4f 3a e3 fd 90 0f 0b e8 47 3a e3
RSP: 0018:ffffc900060df2e0 EFLAGS: 00010293
RAX: ffffffff83e3f321 RBX: ffff88802a26c010 RCX: ffff88802ec5be80
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc900060df880 R08: ffff88802ec5be80 R09: 0000000000000006
R10: 00000000fffffffc R11: 0000000000000000 R12: ffff88802a26c000
R13: 1ffff110041ec81f R14: 0000000000000003 R15: 0000000000000000
FS:  0000555591908500(0000) GS:ffff888124cf3000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc50359f6c CR3: 000000005a889000 CR4: 0000000000350ef0

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/24 02:04 upstream 4352b8aee980 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root kernel BUG in ocfs2_write_begin_nolock
* Struck through repros no longer work on HEAD.