syzbot


WARNING in nilfs_btree_mark

Status: upstream: reported C repro on 2026/03/19 07:21
Subsystems: nilfs
[Documentation on labels]
Reported-by: syzbot+98a040252119df0506f8@syzkaller.appspotmail.com
Fix commit: be3e5d10643d nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty()
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-riscv64 ci-upstream-gce-arm64 ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-usb]
First crash: 28d, last: 1d09h
Cause bisection: failed (error log, bisect log)
  
Discussions (4)
Title Replies (including bot) Last reply
[PATCH] nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty() 2 (2) 2026/03/31 18:08
[PATCH] nilfs2: fix missing continue after -ENOENT in nilfs_ioctl_mark_blocks_dirty() 7 (7) 2026/03/31 00:47
[PATCH v2] nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty() 1 (1) 2026/03/31 00:46
[syzbot] [nilfs?] WARNING in nilfs_btree_mark 0 (6) 2026/03/22 17:35
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in nilfs_btree_mark origin:upstream -1 C 4 4d09h 4d11h 0/3 upstream: reported C repro on 2026/04/11 02:21
linux-6.1 WARNING in nilfs_btree_mark -1 C 4 11d 11d 0/3 upstream: reported C repro on 2026/04/03 20:30
Last patch testing requests (4)
Created Duration User Patch Repo Result
2026/03/20 06:25 17m kartikey406@gmail.com patch upstream error
2026/03/19 08:49 17m kartikey406@gmail.com patch upstream error
2026/03/19 08:25 23m kartikey406@gmail.com patch upstream log
2026/03/19 07:58 18m kartikey406@gmail.com patch upstream error

Sample crash report:
loop0: detected capacity change from 0 to 4096
------------[ cut here ]------------
ret == -ENOENT
WARNING: fs/nilfs2/btree.c:2356 at nilfs_btree_mark+0x1c9/0x210 fs/nilfs2/btree.c:2356, CPU#1: syz.0.17/5978
Modules linked in:
CPU: 1 UID: 0 PID: 5978 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:nilfs_btree_mark+0x1c9/0x210 fs/nilfs2/btree.c:2356
Code: 48 8b 05 fa 0d 70 0f 48 3b 44 24 10 75 26 89 e8 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d e9 c9 1e 64 fd cc e8 b8 7e 19 fe 90 <0f> 0b 90 bd fe ff ff ff eb c3 e8 08 7f 02 08 44 89 f1 80 e1 07 80
RSP: 0018:ffffc900038075b0 EFLAGS: 00010293
RAX: ffffffff83ac2248 RBX: ffff888035117080 RCX: ffff888028170000
RDX: 0000000000000000 RSI: 00000000fffffffe RDI: 00000000fffffffe
RBP: 00000000fffffffe R08: 0000000000000341 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1006a22ee3 R12: ffff88805726c5c0
R13: dffffc0000000000 R14: ffff88805726c588 R15: fffffffffffffff8
FS:  000055558815d500(0000) GS:ffff88812555d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f663fff CR3: 00000000270a5000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 nilfs_bmap_mark+0xba/0x180 fs/nilfs2/bmap.c:402
 nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:764 [inline]
 nilfs_ioctl_prepare_clean_segments+0x49a/0x800 fs/nilfs2/ioctl.c:799
 nilfs_clean_segments+0x18c/0xa50 fs/nilfs2/segment.c:2525
 nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:916 [inline]
 nilfs_ioctl+0x261f/0x2780 fs/nilfs2/ioctl.c:1346
 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+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f97fcd9c799
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:00007fffdfc45fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f97fd015fa0 RCX: 00007f97fcd9c799
RDX: 0000200000000640 RSI: 0000000040786e88 RDI: 0000000000000004
RBP: 00007f97fce32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f97fd015fac R14: 00007f97fd015fa0 R15: 00007f97fd015fa0
 </TASK>

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/22 17:34 upstream 113ae7b4decc 5b92003d .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kasan-gce-root WARNING in nilfs_btree_mark
2026/03/18 09:50 upstream f0caa1d49cc0 c8810548 .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root WARNING in nilfs_btree_mark
2026/03/29 04:11 upstream be762d8b6dd7 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in nilfs_btree_mark
2026/03/22 16:49 upstream 113ae7b4decc 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in nilfs_btree_mark
2026/04/14 04:12 upstream 26ff969926a0 1a086e7c .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in nilfs_btree_mark
2026/04/08 07:41 upstream 3036cd0d3328 2c961e87 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in nilfs_btree_mark
2026/03/22 01:42 upstream a0c83177734a 5b92003d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in nilfs_btree_mark
2026/03/18 09:25 upstream f0caa1d49cc0 c8810548 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in nilfs_btree_mark
2026/04/04 03:14 linux-next cc13002a9f98 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in nilfs_btree_mark
* Struck through repros no longer work on HEAD.