[v5.15] kernel BUG in balance_leaf (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 98f47d0e9b8c Linux 5.15.184
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17ed700c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9eb2b5a65dfc4761
dashboard link: https://syzkaller.appspot.com/bug?extid=1a932d66673a8b904c5d
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d2845fb3af6c/disk-98f47d0e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1f12b743be24/vmlinux-98f47d0e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8f178b57ea38/Image-98f47d0e.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1a932d...@syzkaller.appspotmail.com

REISERFS panic (device loop4): vs-12195 balance_leaf: CFR not initialized
------------[ cut here ]------------
kernel BUG at fs/reiserfs/prints.c:390!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4787 Comm: syz.4.118 Not tainted 5.15.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __reiserfs_panic+0x13c/0x140 fs/reiserfs/prints.c:384
lr : __reiserfs_panic+0x13c/0x140 fs/reiserfs/prints.c:384
sp : ffff800020af6980
x29: ffff800020af6a20 x28: ffff800020af7200 x27: ffff800020af7218
x26: 0000000000000002 x25: dfff800000000000 x24: ffff800020af73a0
x23: ffff800020af69a0 x22: ffff8000113e1ea0 x21: ffff0000f0724000
x20: ffff8000113e1e80 x19: ffff800013870e79 x18: 0000000000000002
x17: ffff800016cdf000 x16: ffff8000111a5644 x15: ffff8000167bf4c0
x14: ffff0000cbb70a00 x13: 1ffff0000282a06b x12: 0000000000080000
x11: 000000000000b6f0 x10: ffff800028290000 x9 : aae4994a4af16900
x8 : aae4994a4af16900 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000000 x3 : ffff80000a732644
x2 : ffff0001a10fbd10 x1 : 0000000100000000 x0 : 0000000000000049
Call trace:
__reiserfs_panic+0x13c/0x140 fs/reiserfs/prints.c:384
balance_leaf+0xa0a8/0xd2f4 fs/reiserfs/do_balan.c:1439
do_balance+0x260/0x778 fs/reiserfs/do_balan.c:1888
reiserfs_insert_item+0x8a8/0x9f4 fs/reiserfs/stree.c:2261
add_save_link+0x2d4/0x4c4 fs/reiserfs/super.c:495
reiserfs_truncate_file+0x308/0x6e4 fs/reiserfs/inode.c:2317
reiserfs_setattr+0x8c8/0xd70 fs/reiserfs/inode.c:3409
notify_change+0xa08/0xcd8 fs/attr.c:505
do_truncate+0x178/0x1f0 fs/open.c:65
vfs_truncate+0x23c/0x2b0 fs/open.c:111
do_sys_truncate+0xe8/0x1b0 fs/open.c:134
__do_sys_truncate fs/open.c:146 [inline]
__se_sys_truncate fs/open.c:144 [inline]
__arm64_sys_truncate+0x5c/0x70 fs/open.c:144
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: 912800a5 911aa2a1 aa1303e4 97ffd888 (d4210000)
---[ end trace 9e48b01e4ff7db5d ]---


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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 98f47d0e9b8c Linux 5.15.184
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=122bb970580000

kernel config: https://syzkaller.appspot.com/x/.config?x=9eb2b5a65dfc4761
dashboard link: https://syzkaller.appspot.com/bug?extid=1a932d66673a8b904c5d
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=104c680c580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10922c82580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d2845fb3af6c/disk-98f47d0e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1f12b743be24/vmlinux-98f47d0e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8f178b57ea38/Image-98f47d0e.gz.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/a1eb0ec5d9f7/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=142bb970580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1a932d...@syzkaller.appspotmail.com

REISERFS panic (device loop0): vs-12195 balance_leaf: CFR not initialized

------------[ cut here ]------------
kernel BUG at fs/reiserfs/prints.c:390!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:

CPU: 1 PID: 4027 Comm: syz-executor588 Not tainted 5.15.184-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __reiserfs_panic+0x13c/0x140 fs/reiserfs/prints.c:384
lr : __reiserfs_panic+0x13c/0x140 fs/reiserfs/prints.c:384

sp : ffff80001f0f62e0
x29: ffff80001f0f6380 x28: ffff80001f0f6b80 x27: ffff80001f0f6b98
x26: 3000000000000000 x25: dfff800000000000 x24: ffff80001f0f6d20
x23: ffff80001f0f6300 x22: ffff8000113e1ea0 x21: ffff0000d66bc000

x20: ffff8000113e1e80 x19: ffff800013870e79 x18: 0000000000000002

x17: 0000000040000000 x16: ffff8000111a5644 x15: 0000000000000002
x14: 0000000000ff0100 x13: 1ffff0000282a06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000000 x9 : 4487240a33273000
x8 : 4487240a33273000 x7 : 0000000000000000 x6 : 0000000000000000

x5 : 0000000000000080 x4 : 0000000000000000 x3 : ffff80000a732644

x2 : ffff0001a111cd10 x1 : 0000000100000000 x0 : 0000000000000049

Call trace:
__reiserfs_panic+0x13c/0x140 fs/reiserfs/prints.c:384
balance_leaf+0xa0a8/0xd2f4 fs/reiserfs/do_balan.c:1439
do_balance+0x260/0x778 fs/reiserfs/do_balan.c:1888

reiserfs_paste_into_item+0x5b4/0x6d0 fs/reiserfs/stree.c:2159
reiserfs_get_block+0x1458/0x34b0 fs/reiserfs/inode.c:1077
__block_write_begin_int+0x3e4/0x1588 fs/buffer.c:2012
__block_write_begin+0x40/0x54 fs/buffer.c:2062
reiserfs_write_begin+0x3c8/0x654 fs/reiserfs/inode.c:2790
generic_perform_write+0x204/0x480 mm/filemap.c:3785
__generic_file_write_iter+0x23c/0x454 mm/filemap.c:3912
generic_file_write_iter+0xb0/0x1b4 mm/filemap.c:3944
do_iter_readv_writev+0x3a0/0x4f8 fs/read_write.c:-1
do_iter_write+0x1c4/0x670 fs/read_write.c:855
vfs_writev fs/read_write.c:928 [inline]
do_pwritev+0x1c8/0x2fc fs/read_write.c:1025
__do_sys_pwritev2 fs/read_write.c:1084 [inline]
__se_sys_pwritev2 fs/read_write.c:1075 [inline]
__arm64_sys_pwritev2+0xd4/0x108 fs/read_write.c:1075

__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: 912800a5 911aa2a1 aa1303e4 97ffd888 (d4210000)

---[ end trace 8c0dd424965e71fd ]---


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