[v6.1] WARNING in nilfs_btree_mark

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syzbot

unread,
Apr 3, 2026, 4:30:29 PM (8 days ago) Apr 3
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: 1989cd3d56e2 Linux 6.1.167
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1422f3d6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b1adc0bfde2d8a4a
dashboard link: https://syzkaller.appspot.com/bug?extid=7129cc66ef0a7ca362fc
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/edd05d4d1a68/disk-1989cd3d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bdc3181e838d/vmlinux-1989cd3d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a78aef5a3a25/Image-1989cd3d.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7129cc...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 15508 at fs/nilfs2/btree.c:2348 nilfs_btree_mark+0x1b4/0x1f8 fs/nilfs2/btree.c:2348
Modules linked in:
CPU: 0 PID: 15508 Comm: syz.5.3223 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : nilfs_btree_mark+0x1b4/0x1f8 fs/nilfs2/btree.c:2348
lr : nilfs_btree_mark+0x1b4/0x1f8 fs/nilfs2/btree.c:2348
sp : ffff800021ac7550
x29: ffff800021ac7570 x28: dfff800000000000 x27: 0000000000000000
x26: ffff800021ce3020 x25: 1fffe0001bf6201e x24: dfff800000000000
x23: ffff800011f54be0 x22: 000000000000006d x21: ffff0000dfb10018
x20: 00000000fffffffe x19: ffff0000ccc31680 x18: ffff800011b9bf60
x17: 1fffe00033ea637e x16: ffff8000082d92bc x15: 0000000040000000
x14: 0000000000000004 x13: 1fffe0001998639f x12: 0000000000080000
x11: 00000000000191b7 x10: ffff8000336ee000 x9 : ffff800009c5de64
x8 : 00000000000191b8 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000000 x4 : 000000000000006e x3 : ffff800021ac7558
x2 : 00000000ffffffff x1 : 00000000fffffffe x0 : 00000000fffffffe
Call trace:
nilfs_btree_mark+0x1b4/0x1f8 fs/nilfs2/btree.c:2348
nilfs_bmap_mark+0xb8/0x17c fs/nilfs2/bmap.c:420
nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:779 [inline]
nilfs_ioctl_prepare_clean_segments+0x3ac/0x730 fs/nilfs2/ioctl.c:814
nilfs_clean_segments+0x148/0x870 fs/nilfs2/segment.c:2516
nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:940 [inline]
nilfs_ioctl+0x22c0/0x2660 fs/nilfs2/ioctl.c:1304
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 12616
hardirqs last enabled at (12615): [<ffff800008257a18>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1374 [inline]
hardirqs last enabled at (12615): [<ffff800008257a18>] finish_lock_switch+0xb0/0x1c4 kernel/sched/core.c:5004
hardirqs last disabled at (12616): [<ffff800011a33e5c>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (12424): [<ffff800008030954>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (12422): [<ffff800008030920>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 15508 at fs/nilfs2/ioctl.c:782 nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:782 [inline]
WARNING: CPU: 0 PID: 15508 at fs/nilfs2/ioctl.c:782 nilfs_ioctl_prepare_clean_segments+0x6bc/0x730 fs/nilfs2/ioctl.c:814
Modules linked in:
CPU: 0 PID: 15508 Comm: syz.5.3223 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:782 [inline]
pc : nilfs_ioctl_prepare_clean_segments+0x6bc/0x730 fs/nilfs2/ioctl.c:814
lr : nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:782 [inline]
lr : nilfs_ioctl_prepare_clean_segments+0x6bc/0x730 fs/nilfs2/ioctl.c:814
sp : ffff800021ac7600
x29: ffff800021ac76a0 x28: dfff800000000000 x27: 0000000000000000
x26: ffff800021ce3020 x25: ffff800021ce3018 x24: 00000000fffffffe
x23: 1ffff0000439c603 x22: 1ffff0000439c602 x21: ffff800021ce3000
x20: ffff0000da0792c8 x19: 0000000000000001 x18: ffff800011b9bf60
x17: ffff80001835a000 x16: ffff8000082d92bc x15: ffff8000089f00b4
x14: 0000000000000001 x13: 1fffe0001bf6200a x12: 0000000000080000
x11: 0000000000035ac1 x10: ffff8000336ee000 x9 : ffff800009c9c780
x8 : 0000000000035ac2 x7 : ffff80000805983c x6 : ffff800008059a4c
x5 : ffff0000e729f970 x4 : ffff800021ac7238 x3 : ffff8000082d27a8
x2 : 0000000000000001 x1 : 00000000fffffffe x0 : 00000000fffffffe
Call trace:
nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:782 [inline]
nilfs_ioctl_prepare_clean_segments+0x6bc/0x730 fs/nilfs2/ioctl.c:814
nilfs_clean_segments+0x148/0x870 fs/nilfs2/segment.c:2516
nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:940 [inline]
nilfs_ioctl+0x22c0/0x2660 fs/nilfs2/ioctl.c:1304
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 12728
hardirqs last enabled at (12727): [<ffff8000088e81cc>] kasan_quarantine_put+0xc4/0x200 mm/kasan/quarantine.c:242
hardirqs last disabled at (12728): [<ffff800011a33e5c>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (12716): [<ffff8000081ac394>] softirq_handle_end kernel/softirq.c:439 [inline]
softirqs last enabled at (12716): [<ffff8000081ac394>] handle_softirqs+0xaec/0xc60 kernel/softirq.c:624
softirqs last disabled at (12619): [<ffff800008020164>] __do_softirq+0x14/0x20 kernel/softirq.c:630
---[ end trace 0000000000000000 ]---
NILFS (loop5): error -2 preparing GC: cannot mark copying blocks dirty


---
This report is generated by a bot. It may contain errors.
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syzbot

unread,
Apr 3, 2026, 4:59:24 PM (8 days ago) Apr 3
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:

HEAD commit: 1989cd3d56e2 Linux 6.1.167
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=143088f2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b1adc0bfde2d8a4a
dashboard link: https://syzkaller.appspot.com/bug?extid=7129cc66ef0a7ca362fc
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=150335da580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=153218d2580000
mounted in repro: https://storage.googleapis.com/syzbot-assets/f20295cca8e7/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7129cc...@syzkaller.appspotmail.com

=======================================================
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4475 at fs/nilfs2/btree.c:2348 nilfs_btree_mark+0x1b4/0x1f8 fs/nilfs2/btree.c:2348
Modules linked in:
CPU: 1 PID: 4475 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : nilfs_btree_mark+0x1b4/0x1f8 fs/nilfs2/btree.c:2348
lr : nilfs_btree_mark+0x1b4/0x1f8 fs/nilfs2/btree.c:2348
sp : ffff800020ee7550
x29: ffff800020ee7570 x28: dfff800000000000 x27: 0000000000000000
x26: ffff800020939020 x25: 1fffe0001d56e01e x24: dfff800000000000
x23: ffff800011f54be0 x22: 000000000000006d x21: ffff0000eab70018
x20: 00000000fffffffe x19: ffff0000dae29680 x18: 0000000000000000
x17: ffff80001835a000 x16: ffff8000082d92bc x15: ffff8000089f00b4
x14: 0000000000000004 x13: 1fffe0001b5c539f x12: 0000000000ff0100
x11: ff00800009c5de64 x10: 0000000000000000 x9 : ffff800009c5de64
x8 : ffff0000d2d9d340 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000000 x4 : 000000000000006e x3 : ffff800020ee7558
x2 : 00000000ffffffff x1 : 00000000fffffffe x0 : 00000000fffffffe
Call trace:
nilfs_btree_mark+0x1b4/0x1f8 fs/nilfs2/btree.c:2348
nilfs_bmap_mark+0xb8/0x17c fs/nilfs2/bmap.c:420
nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:779 [inline]
nilfs_ioctl_prepare_clean_segments+0x3ac/0x730 fs/nilfs2/ioctl.c:814
nilfs_clean_segments+0x148/0x870 fs/nilfs2/segment.c:2516
nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:940 [inline]
nilfs_ioctl+0x22c0/0x2660 fs/nilfs2/ioctl.c:1304
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 13680
hardirqs last enabled at (13679): [<ffff800011b1ef94>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last enabled at (13679): [<ffff800011b1ef94>] _raw_spin_unlock_irqrestore+0x48/0xac kernel/locking/spinlock.c:194
hardirqs last disabled at (13680): [<ffff800011a33e5c>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (13624): [<ffff800008030954>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (13622): [<ffff800008030920>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4475 at fs/nilfs2/ioctl.c:782 nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:782 [inline]
WARNING: CPU: 1 PID: 4475 at fs/nilfs2/ioctl.c:782 nilfs_ioctl_prepare_clean_segments+0x6bc/0x730 fs/nilfs2/ioctl.c:814
Modules linked in:
CPU: 1 PID: 4475 Comm: syz.0.17 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:782 [inline]
pc : nilfs_ioctl_prepare_clean_segments+0x6bc/0x730 fs/nilfs2/ioctl.c:814
lr : nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:782 [inline]
lr : nilfs_ioctl_prepare_clean_segments+0x6bc/0x730 fs/nilfs2/ioctl.c:814
sp : ffff800020ee7600
x29: ffff800020ee76a0 x28: dfff800000000000 x27: 0000000000000000
x26: ffff800020939020 x25: ffff800020939018 x24: 00000000fffffffe
x23: 1ffff00004127203 x22: 1ffff00004127202 x21: ffff800020939000
x20: ffff0000d1ea52c8 x19: 0000000000000001 x18: 0000000000000000
x17: ffff80001835a000 x16: ffff8000082d92bc x15: ffff8000089f00b4
x14: 0000000000000001 x13: 1fffe0001d56e00a x12: 0000000000ff0100
x11: ff00800009c9c780 x10: 0000000000000000 x9 : ffff800009c9c780
x8 : ffff0000d2d9d340 x7 : ffff80000805983c x6 : ffff800008059a4c
x5 : ffff0000d9e7f890 x4 : ffff800020ee7238 x3 : ffff8000082d27a8
x2 : 0000000000000001 x1 : 00000000fffffffe x0 : 00000000fffffffe
Call trace:
nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:782 [inline]
nilfs_ioctl_prepare_clean_segments+0x6bc/0x730 fs/nilfs2/ioctl.c:814
nilfs_clean_segments+0x148/0x870 fs/nilfs2/segment.c:2516
nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:940 [inline]
nilfs_ioctl+0x22c0/0x2660 fs/nilfs2/ioctl.c:1304
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 13798
hardirqs last enabled at (13797): [<ffff8000088e81cc>] kasan_quarantine_put+0xc4/0x200 mm/kasan/quarantine.c:242
hardirqs last disabled at (13798): [<ffff800011a33e5c>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (13786): [<ffff8000081ac394>] softirq_handle_end kernel/softirq.c:439 [inline]
softirqs last enabled at (13786): [<ffff8000081ac394>] handle_softirqs+0xaec/0xc60 kernel/softirq.c:624
softirqs last disabled at (13683): [<ffff800008020164>] __do_softirq+0x14/0x20 kernel/softirq.c:630
---[ end trace 0000000000000000 ]---
NILFS (loop0): error -2 preparing GC: cannot mark copying blocks dirty


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

syzbot

unread,
Apr 10, 2026, 10:21:22 PM (19 hours ago) Apr 10
to syzkaller...@googlegroups.com
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=1570474e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=96be415417e9468fb7e1
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+96be41...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 11535 at fs/nilfs2/btree.c:2349 nilfs_btree_mark+0x1c1/0x200 fs/nilfs2/btree.c:2349
Modules linked in:
CPU: 0 PID: 11535 Comm: syz.5.1695 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:nilfs_btree_mark+0x1c1/0x200 fs/nilfs2/btree.c:2349
Code: f5 25 00 00 65 48 8b 04 25 28 00 00 00 48 3b 44 24 10 75 1f 89 e8 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 bf 22 6b fe <0f> 0b bd fe ff ff ff eb c9 e8 61 6a ae 06 44 89 f1 80 e1 07 80 c1
RSP: 0018:ffffc9000343f6b0 EFLAGS: 00010287
RAX: ffffffff830dfe51 RBX: ffff88807c9a2d00 RCX: 0000000000080000
RDX: ffffc90015e3e000 RSI: 000000000000dd20 RDI: 000000000000dd21
RBP: 00000000fffffffe R08: 00000000208a0b70 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100f934673 R12: ffff888071f92d28
R13: dffffc0000000000 R14: ffff888071f92cf0 R15: 36744777f4de0100
FS: 00007fcc482f36c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4526a1c000 CR3: 00000000647ea000 CR4: 00000000003506f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002
DR3: ffffffffefffff15 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
nilfs_bmap_mark+0xb0/0x170 fs/nilfs2/bmap.c:420
nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:779 [inline]
nilfs_ioctl_prepare_clean_segments+0x494/0x7f0 fs/nilfs2/ioctl.c:814
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: 0033:0x7fcc4a099819
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:00007fcc482f3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcc4a312fa0 RCX: 00007fcc4a099819
RDX: 0000200000000000 RSI: 0000000040786e88 RDI: 0000000000000005
RBP: 00007fcc4a12fc91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcc4a313038 R14: 00007fcc4a312fa0 R15: 00007fffc22f8138
</TASK>

syzbot

unread,
Apr 10, 2026, 10:49:30 PM (18 hours ago) Apr 10
to syzkaller...@googlegroups.com
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=1446fbd6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=96be415417e9468fb7e1
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=15375eba580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1707b302580000
mounted in repro: https://storage.googleapis.com/syzbot-assets/bd11c34975b5/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+96be41...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 4096
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4363 at fs/nilfs2/btree.c:2349 nilfs_btree_mark+0x1c1/0x200 fs/nilfs2/btree.c:2349
Modules linked in:
CPU: 1 PID: 4363 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:nilfs_btree_mark+0x1c1/0x200 fs/nilfs2/btree.c:2349
Code: f5 25 00 00 65 48 8b 04 25 28 00 00 00 48 3b 44 24 10 75 1f 89 e8 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 bf 22 6b fe <0f> 0b bd fe ff ff ff eb c9 e8 61 6a ae 06 44 89 f1 80 e1 07 80 c1
RSP: 0018:ffffc9000363f6b0 EFLAGS: 00010293
RAX: ffffffff830dfe51 RBX: ffff88807b087800 RCX: ffff8880225f8000
RDX: 0000000000000000 RSI: 00000000fffffffe RDI: 00000000fffffffe
RBP: 00000000fffffffe R08: 00000000208a0b70 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100f610fd3 R12: ffff88805c7a0050
R13: dffffc0000000000 R14: ffff88805c7a0018 R15: 36744777f4de0100
FS: 0000555580042500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6c3d7ea000 CR3: 0000000023abc000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
nilfs_bmap_mark+0xb0/0x170 fs/nilfs2/bmap.c:420
nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:779 [inline]
nilfs_ioctl_prepare_clean_segments+0x494/0x7f0 fs/nilfs2/ioctl.c:814
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: 0033:0x7eff25b27819
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:00007ffe0262ce08 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007eff25da0fa0 RCX: 00007eff25b27819
RDX: 0000200000000000 RSI: 0000000040786e88 RDI: 0000000000000004
RBP: 00007eff25bbdc91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007eff25da0fac R14: 00007eff25da0fa0 R15: 00007eff25da0fa0
</TASK>
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