syzbot


WARNING in nilfs_ioctl_prepare_clean_segments

Status: upstream: reported C repro on 2026/04/04 09:10
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+49368453b1b74097e0e9@syzkaller.appspotmail.com
First crash: 2d16h, last: 2d14h
Bug presence (1)
Date Name Commit Repro Result
2026/04/04 upstream (ToT) 7ca6d1cfec80 C [report] WARNING in nilfs_ioctl_prepare_clean_segments
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in nilfs_ioctl_prepare_clean_segments nilfs -1 C error 3 21h38m 20d 0/29 upstream: reported C repro on 2026/03/17 03:25

Sample crash report:
loop0: detected capacity change from 0 to 4096
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4303 at fs/nilfs2/ioctl.c:772 nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:772 [inline]
WARNING: CPU: 0 PID: 4303 at fs/nilfs2/ioctl.c:772 nilfs_ioctl_prepare_clean_segments+0x7da/0x7f0 fs/nilfs2/ioctl.c:814
Modules linked in:
CPU: 1 PID: 4303 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:772 [inline]
RIP: 0010:nilfs_ioctl_prepare_clean_segments+0x7da/0x7f0 fs/nilfs2/ioctl.c:814
Code: ab fe e9 47 fa ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c dd fa ff ff 4c 89 ef e8 b0 c6 ab fe e9 d0 fa ff ff e8 56 bb 66 fe <0f> 0b 41 bf fe ff ff ff e9 eb fe ff ff 66 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90002f3f740 EFLAGS: 00010293
RAX: ffffffff831265ba RBX: 00000000fffffffe RCX: ffff888016e40000
RDX: 0000000000000000 RSI: ffffffff8c7613f0 RDI: 00000000fffffffe
RBP: ffffc90002f3f830 R08: ffff888016e40000 R09: 0000000000000002
R10: 00000000fffffffe R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000002 R14: ffff888060eb0158 R15: ffffc90001176018
FS:  000055558582c500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056185b74ff10 CR3: 000000001f975000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 nilfs_clean_segments+0x189/0xa30 fs/nilfs2/segment.c:2518
 nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:940 [inline]
 nilfs_ioctl+0x2052/0x2190 fs/nilfs2/ioctl.c:1304
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5834535819
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:00007ffcfe524928 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f58347aefa0 RCX: 00007f5834535819
RDX: 0000200000000640 RSI: 0000000040786e88 RDI: 0000000000000004
RBP: 00007f58345cbc91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f58347aefac R14: 00007f58347aefa0 R15: 00007f58347aefa0
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/04 10:59 linux-5.15.y 91d48252ad4b 4440e7c2 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan WARNING in nilfs_ioctl_prepare_clean_segments
2026/04/04 10:04 linux-5.15.y 91d48252ad4b 4440e7c2 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan WARNING in nilfs_ioctl_prepare_clean_segments
2026/04/04 09:09 linux-5.15.y 91d48252ad4b 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in nilfs_ioctl_prepare_clean_segments
* Struck through repros no longer work on HEAD.