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WARNING in nilfs_btree_mark

Status: upstream: reported C repro on 2026/04/03 20:30
Reported-by: syzbot+7129cc66ef0a7ca362fc@syzkaller.appspotmail.com
First crash: 10d, last: 9d23h
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2026/04/04 upstream (ToT) 631919fb12fe C Failed due to an error; will retry later
▶ ▼ 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 2d17h 2d18h 0/3 upstream: reported C repro on 2026/04/11 02:21
upstream WARNING in nilfs_btree_mark nilfs -1 C error 8 5d13h 25d 0/29 upstream: reported C repro on 2026/03/19 07:21

Sample crash report:
=======================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4451 at fs/nilfs2/btree.c:2348 nilfs_btree_mark+0x1b4/0x1f8 fs/nilfs2/btree.c:2348
Modules linked in:
CPU: 0 PID: 4451 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 : ffff800021507550
x29: ffff800021507570 x28: dfff800000000000 x27: 0000000000000000
x26: ffff800020ebb020 x25: 1fffe0001d42401e x24: dfff800000000000
x23: ffff800011f54be0 x22: 000000000000006d x21: ffff0000ea120018
x20: 00000000fffffffe x19: ffff0000cec09680 x18: 0000000000000000
x17: ffff80001835a000 x16: ffff8000082d92bc x15: ffff8000089f00b4
x14: 0000000000000004 x13: 1fffe00019d8139f x12: 0000000000ff0100
x11: ff00800009c5de64 x10: 0000000000000000 x9 : ffff800009c5de64
x8 : ffff0000d1c6b780 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000000 x4 : 000000000000006e x3 : ffff800021507558
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: 13558
hardirqs last  enabled at (13557): [<ffff800011b1ef94>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (13557): [<ffff800011b1ef94>] _raw_spin_unlock_irqrestore+0x48/0xac kernel/locking/spinlock.c:194
hardirqs last disabled at (13558): [<ffff800011a33e5c>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (13500): [<ffff800008030954>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (13498): [<ffff800008030920>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4451 at fs/nilfs2/ioctl.c:782 nilfs_ioctl_mark_blocks_dirty fs/nilfs2/ioctl.c:782 [inline]
WARNING: CPU: 0 PID: 4451 at fs/nilfs2/ioctl.c:782 nilfs_ioctl_prepare_clean_segments+0x6bc/0x730 fs/nilfs2/ioctl.c:814
Modules linked in:
CPU: 0 PID: 4451 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 : ffff800021507600
x29: ffff8000215076a0 x28: dfff800000000000 x27: 0000000000000000
x26: ffff800020ebb020 x25: ffff800020ebb018 x24: 00000000fffffffe
x23: 1ffff000041d7603 x22: 1ffff000041d7602 x21: ffff800020ebb000
x20: ffff0000dc9a22c8 x19: 0000000000000001 x18: 0000000000000000
x17: ffff80001835a000 x16: ffff8000082d92bc x15: ffff8000089f00b4
x14: 0000000000000001 x13: 1fffe0001d42400a x12: 0000000000ff0100
x11: ff00800009c9c780 x10: 0000000000000000 x9 : ffff800009c9c780
x8 : ffff0000d1c6b780 x7 : ffff80000805983c x6 : ffff800008059a4c
x5 : ffff0000cfaf7920 x4 : ffff800021507238 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: 13650
hardirqs last  enabled at (13649): [<ffff8000088e81cc>] kasan_quarantine_put+0xc4/0x200 mm/kasan/quarantine.c:242
hardirqs last disabled at (13650): [<ffff800011a33e5c>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (13638): [<ffff8000081ac394>] softirq_handle_end kernel/softirq.c:439 [inline]
softirqs last  enabled at (13638): [<ffff8000081ac394>] handle_softirqs+0xaec/0xc60 kernel/softirq.c:624
softirqs last disabled at (13561): [<ffff800008020164>] __do_softirq+0x14/0x20 kernel/softirq.c:630
---[ end trace 0000000000000000 ]---
NILFS (loop0): error -2 preparing GC: cannot mark copying blocks dirty

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/03 21:22 linux-6.1.y 1989cd3d56e2 4440e7c2 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 WARNING in nilfs_btree_mark
2026/04/03 20:58 linux-6.1.y 1989cd3d56e2 4440e7c2 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 WARNING in nilfs_btree_mark
2026/04/03 20:30 linux-6.1.y 1989cd3d56e2 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in nilfs_btree_mark
2026/04/03 20:30 linux-6.1.y 1989cd3d56e2 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in nilfs_btree_mark
* Struck through repros no longer work on HEAD.