syzbot


kernel BUG in nilfs_copy_dirty_pages

Status: upstream: reported on 2026/04/12 12:32
Subsystems: nilfs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+8baf9a79a3ffc6271cb6@syzkaller.appspotmail.com
First crash: 100d, last: 4d18h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
52ed33eb-5d8d-4ada-8d24-66b9b6c936fd assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ kernel BUG in nilfs_copy_dirty_pages 2026/05/15 23:36 2026/05/15 23:36 2026/05/16 00:30 efdaf0f9b8bfc56ea6d17bea15a64f4591cc712d

			
		
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly nilfs report (Jul 2026) 0 (1) 2026/07/17 04:32
[syzbot] [nilfs?] kernel BUG in nilfs_copy_dirty_pages 0 (1) 2026/04/12 12:32

Sample crash report:
loop0: detected capacity change from 0 to 4096
=======================================================
WARNING: The mand mount option has been deprecated and
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
NILFS (loop0): DAT doesn't have a block to manage vblocknr = 524288
NILFS error (device loop0): nilfs_bmap_truncate: broken bmap (inode number=15)
Remounting filesystem read-only
NILFS (loop0): error -5 truncating bmap (ino=15)
NILFS_FOLIO_BUG(ffffea0000481080): cnt=3 index#=0 flags=0xfff80000004025 mapping=ffff888044210978 ino=3
 BH[0] ffff88801300ac40: cnt=1 block#=28 state=0x1b
------------[ cut here ]------------
kernel BUG at fs/nilfs2/page.c:262!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5330 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:nilfs_copy_dirty_pages+0x595/0x5f0 fs/nilfs2/page.c:262
Code: 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 b3 28 f6 fd e9 66 ff ff ff e8 e9 ca 00 08 e8 a4 28 f6 fd 4c 89 ff e8 0c f8 ff ff 90 <0f> 0b e8 94 28 f6 fd 4c 89 ff 48 c7 c6 20 bd 32 8c e8 95 c5 57 fd
RSP: 0018:ffffc9000f7df4e0 EFLAGS: 00010293
RAX: ffffffff83d05314 RBX: 0000000000000000 RCX: ffff88800022ca80
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc9000f7df6f8 R08: ffff88801fc24713 R09: 1ffff11003f848e2
R10: dffffc0000000000 R11: ffffed1003f848e3 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffffd4000090211 R15: ffffea0000481080
FS:  00007ff6038bb6c0(0000) GS:ffff88808c54d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbe19f3a3d0 CR3: 000000001f10e000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 nilfs_mdt_save_to_shadow_map+0xbb/0x1c0 fs/nilfs2/mdt.c:552
 nilfs_clean_segments+0x28d/0xbb0 fs/nilfs2/segment.c:2542
 nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:922 [inline]
 nilfs_ioctl+0x2619/0x2780 fs/nilfs2/ioctl.c:1352
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff60299de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff6038bafe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff602c25fa0 RCX: 00007ff60299de59
RDX: 0000200000000640 RSI: 0000000040786e88 RDI: 0000000000000004
RBP: 00007ff602a33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff602c26038 R14: 00007ff602c25fa0 R15: 00007ffd1481d2a8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:nilfs_copy_dirty_pages+0x595/0x5f0 fs/nilfs2/page.c:262
Code: 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 b3 28 f6 fd e9 66 ff ff ff e8 e9 ca 00 08 e8 a4 28 f6 fd 4c 89 ff e8 0c f8 ff ff 90 <0f> 0b e8 94 28 f6 fd 4c 89 ff 48 c7 c6 20 bd 32 8c e8 95 c5 57 fd
RSP: 0018:ffffc9000f7df4e0 EFLAGS: 00010293
RAX: ffffffff83d05314 RBX: 0000000000000000 RCX: ffff88800022ca80
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc9000f7df6f8 R08: ffff88801fc24713 R09: 1ffff11003f848e2
R10: dffffc0000000000 R11: ffffed1003f848e3 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffffd4000090211 R15: ffffea0000481080
FS:  00007ff6038bb6c0(0000) GS:ffff88808c54d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd1481cac0 CR3: 000000001f10e000 CR4: 0000000000352ef0

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/13 05:43 upstream f4fb100039e9 d78ea535 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in nilfs_copy_dirty_pages
2026/04/08 12:27 upstream 3036cd0d3328 2c961e87 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in nilfs_copy_dirty_pages
* Struck through repros no longer work on HEAD.