[v5.15] WARNING in nilfs_ioctl_prepare_clean_segments

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 91d48252ad4b Linux 5.15.202
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=147688f2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=49368453b1b74097e0e9
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/74e75dfcb812/disk-91d48252.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bfa72aab00f2/vmlinux-91d48252.xz
kernel image: https://storage.googleapis.com/syzbot-assets/47ea72d1c7dc/bzImage-91d48252.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+493684...@syzkaller.appspotmail.com

loop5: detected capacity change from 0 to 4096
------------[ cut here ]------------
WARNING: CPU: 1 PID: 11944 at fs/nilfs2/ioctl.c:772 nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:772 [inline]
WARNING: CPU: 1 PID: 11944 at fs/nilfs2/ioctl.c:772 nilfs_ioctl_prepare_clean_segments+0x7da/0x7f0 fs/nilfs2/ioctl.c:814
Modules linked in:
CPU: 0 PID: 11944 Comm: syz.5.1750 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:ffffc90004657740 EFLAGS: 00010287
RAX: ffffffff831265ba RBX: 00000000fffffffe RCX: 0000000000080000
RDX: ffffc90016800000 RSI: 0000000000001311 RDI: 0000000000001312
RBP: ffffc90004657830 R08: ffff88802ca38000 R09: 0000000000000002
R10: 00000000fffffffe R11: 0000000000000002 R12: dffffc0000000000
R13: 0000000000000002 R14: ffff88805a90c7d0 R15: ffffc90003221018
FS: 00007f6d56bfa6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fee3aa7bf00 CR3: 000000002d89c000 CR4: 00000000003526e0
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: 0033:0x7f6d589a0819
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:00007f6d56bfa028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f6d58c19fa0 RCX: 00007f6d589a0819
RDX: 0000200000000640 RSI: 0000000040786e88 RDI: 0000000000000007
RBP: 00007f6d58a36c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6d58c1a038 R14: 00007f6d58c19fa0 R15: 00007fff8235f5b8
</TASK>


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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 91d48252ad4b Linux 5.15.202
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=109530f2580000

kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=49368453b1b74097e0e9
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1199f3d6580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17cac1ca580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/74e75dfcb812/disk-91d48252.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bfa72aab00f2/vmlinux-91d48252.xz
kernel image: https://storage.googleapis.com/syzbot-assets/47ea72d1c7dc/bzImage-91d48252.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/d150b77c1d8f/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+493684...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 4096
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4331 at fs/nilfs2/ioctl.c:772 nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:772 [inline]
WARNING: CPU: 0 PID: 4331 at fs/nilfs2/ioctl.c:772 nilfs_ioctl_prepare_clean_segments+0x7da/0x7f0 fs/nilfs2/ioctl.c:814
Modules linked in:
CPU: 0 PID: 4331 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:ffffc90002f6f740 EFLAGS: 00010293
RAX: ffffffff831265ba RBX: 00000000fffffffe RCX: ffff888020fc0000
RDX: 0000000000000000 RSI: ffffffff8c7613f0 RDI: 00000000fffffffe
RBP: ffffc90002f6f830 R08: ffff888020fc0000 R09: 0000000000000002
R10: 00000000fffffffe R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000002 R14: ffff88805b828158 R15: ffffc900011cc018
FS: 0000555571959500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 0000001b2fc63fff CR3: 000000007dbd4000 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: 0033:0x7f2c826b7819

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:00007ffc53ae7f98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2c82930fa0 RCX: 00007f2c826b7819
RDX: 0000200000000640 RSI: 0000000040786e88 RDI: 0000000000000004
RBP: 00007f2c8274dc91 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007f2c82930fac R14: 00007f2c82930fa0 R15: 00007f2c82930fa0
</TASK>


---
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