[v6.1] WARNING in ext4_update_dx_flag

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 882efbdd9d34 Linux 6.1.155
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1298a542580000
kernel config: https://syzkaller.appspot.com/x/.config?x=68aa5a3af1cb953a
dashboard link: https://syzkaller.appspot.com/bug?extid=ee9c1340f1991b5b827f
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ace97ceaac60/disk-882efbdd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/88315d1cd2fa/vmlinux-882efbdd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5e607a61f425/Image-882efbdd.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ee9c13...@syzkaller.appspotmail.com

EXT4-fs warning (device loop1): ext4_dirblock_csum_set:427: inode #2: comm syz.1.294: No space for directory leaf checksum. Please run e2fsck -D.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5780 at fs/ext4/ext4.h:2827 ext4_update_dx_flag+0x14c/0x1b0 fs/ext4/ext4.h:2827
Modules linked in:
CPU: 0 PID: 5780 Comm: syz.1.294 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : ext4_update_dx_flag+0x14c/0x1b0 fs/ext4/ext4.h:2827
lr : ext4_update_dx_flag+0x14c/0x1b0 fs/ext4/ext4.h:2827
sp : ffff8000219376a0
x29: ffff8000219376b0 x28: ffff700004326ee0 x27: ffff0000e259bf50
x26: dfff800000000000 x25: 0000000005007864 x24: ffff0000e259bf48
x23: 0000000000000001 x22: 000000000008d200 x21: dfff800000000000
x20: 00000000ffeffffe x19: ffff0000e259bc80 x18: ffff800011abbcc0
x17: ffff8000181f8000 x16: ffff8000082d22e0 x15: ffff800017cd8fc0
x14: ffff0000d8a60a98 x13: 0000000005007864 x12: 0000000000080000
x11: 0000000000015c0f x10: ffff800021cab000 x9 : ffff800008dc2284
x8 : 0000000000015c10 x7 : 0000000005007864 x6 : 0000000000000043
x5 : ffff0000e259bf68 x4 : ffff0000e259bf58 x3 : ffff800008dc82c8
x2 : 0000000000000010 x1 : 0000000000000400 x0 : 0000000000000000
Call trace:
ext4_update_dx_flag+0x14c/0x1b0 fs/ext4/ext4.h:2827
ext4_rename fs/ext4/namei.c:4010 [inline]
ext4_rename2+0x1954/0x24a0 fs/ext4/namei.c:4258
vfs_rename+0x954/0xdcc fs/namei.c:4874
do_renameat2+0x738/0xa54 fs/namei.c:5027
__do_sys_renameat2 fs/namei.c:5060 [inline]
__se_sys_renameat2 fs/namei.c:5057 [inline]
__arm64_sys_renameat2+0xe0/0xfc fs/namei.c:5057
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 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: 10156
hardirqs last enabled at (10155): [<ffff8000083bf2e4>] seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline]
hardirqs last enabled at (10155): [<ffff8000083bf2e4>] ktime_get_coarse_real_ts64+0x114/0x244 kernel/time/timekeeping.c:2261
hardirqs last disabled at (10156): [<ffff80001195a4d8>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (9990): [<ffff80000803092c>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (9988): [<ffff8000080308f8>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---
EXT4-fs error (device loop1): __ext4_get_inode_loc:4507: comm syz.1.294: Invalid inode table block 15278364334593457450 in block_group 0
EXT4-fs error (device loop1) in ext4_reserve_inode_write:5915: Corrupt filesystem
EXT4-fs error (device loop1): ext4_rename:4030: inode #2: comm syz.1.294: mark_inode_dirty error


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 882efbdd9d34 Linux 6.1.155
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=16fe5304580000

kernel config: https://syzkaller.appspot.com/x/.config?x=68aa5a3af1cb953a
dashboard link: https://syzkaller.appspot.com/bug?extid=ee9c1340f1991b5b827f
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10dda9e2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1440f458580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ace97ceaac60/disk-882efbdd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/88315d1cd2fa/vmlinux-882efbdd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5e607a61f425/Image-882efbdd.gz.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/4ef6b493636c/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=13ad5892580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ee9c13...@syzkaller.appspotmail.com

EXT4-fs (loop0): This should not happen!! Data will be lost
EXT4-fs warning (device loop0): ext4_dirblock_csum_set:427: inode #2: comm syz.0.17: No space for directory leaf checksum. Please run e2fsck -D.
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4509 at fs/ext4/ext4.h:2827 ext4_update_dx_flag+0x14c/0x1b0 fs/ext4/ext4.h:2827
Modules linked in:
CPU: 1 PID: 4509 Comm: syz.0.17 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : ext4_update_dx_flag+0x14c/0x1b0 fs/ext4/ext4.h:2827
lr : ext4_update_dx_flag+0x14c/0x1b0 fs/ext4/ext4.h:2827

sp : ffff8000224a76a0
x29: ffff8000224a76b0 x28: ffff700004494ee0 x27: ffff0000e9e22b40
x26: dfff800000000000 x25: 0000000024f47300 x24: ffff0000e9e22b38

x23: 0000000000000001 x22: 000000000008d200 x21: dfff800000000000

x20: 00000000ffeffffe x19: ffff0000e9e22870 x18: 0000000000000000

x17: ffff8000181f8000 x16: ffff8000082d22e0 x15: ffff800017cd8fc0

x14: ffff0000cd38a658 x13: 0000000024f47300 x12: 0000000000ff0100
x11: ff00800008dc2284 x10: 0000000000000000 x9 : ffff800008dc2284
x8 : ffff0000cd389bc0 x7 : 0000000024f47300 x6 : 0000000000000033
x5 : ffff0000e9e22b58 x4 : ffff0000e9e22b48 x3 : ffff800008dc82c8

x2 : 0000000000000010 x1 : 0000000000000400 x0 : 0000000000000000
Call trace:
ext4_update_dx_flag+0x14c/0x1b0 fs/ext4/ext4.h:2827
ext4_rename fs/ext4/namei.c:4010 [inline]
ext4_rename2+0x1954/0x24a0 fs/ext4/namei.c:4258
vfs_rename+0x954/0xdcc fs/namei.c:4874
do_renameat2+0x738/0xa54 fs/namei.c:5027
__do_sys_renameat2 fs/namei.c:5060 [inline]
__se_sys_renameat2 fs/namei.c:5057 [inline]
__arm64_sys_renameat2+0xe0/0xfc fs/namei.c:5057
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 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: 12158
hardirqs last enabled at (12157): [<ffff8000083bf2e4>] seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline]
hardirqs last enabled at (12157): [<ffff8000083bf2e4>] ktime_get_coarse_real_ts64+0x114/0x244 kernel/time/timekeeping.c:2261
hardirqs last disabled at (12158): [<ffff80001195a4d8>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (12000): [<ffff80000803092c>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (11998): [<ffff8000080308f8>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19

---[ end trace 0000000000000000 ]---

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