[syzbot] [udf?] KMSAN: uninit-value in udf_name_from_CS0

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e6bc8833d80f string: use __builtin_memcpy() in strlcpy/str..
git tree: https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=16c43f97280000
kernel config: https://syzkaller.appspot.com/x/.config?x=6a7e173060c804ee
dashboard link: https://syzkaller.appspot.com/bug?extid=cd311b1e43cc25f90d18
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: i386

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/df1e5cb3acfa/disk-e6bc8833.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/55bdfe53ed68/vmlinux-e6bc8833.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3e2a33babf5f/bzImage-e6bc8833.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cd311b...@syzkaller.appspotmail.com

UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000)
=====================================================
BUG: KMSAN: uninit-value in udf_name_from_CS0+0x1581/0x1a40 fs/udf/unicode.c:250
udf_name_from_CS0+0x1581/0x1a40 fs/udf/unicode.c:250
udf_get_filename+0xa4/0x150 fs/udf/unicode.c:390
udf_fiiter_find_entry+0x77b/0xa60 fs/udf/namei.c:90
udf_unlink+0x80/0x920 fs/udf/namei.c:547
vfs_unlink+0x66f/0xa20 fs/namei.c:4327
do_unlinkat+0x3fa/0xed0 fs/namei.c:4393
__do_sys_unlink fs/namei.c:4441 [inline]
__se_sys_unlink fs/namei.c:4439 [inline]
__ia32_sys_unlink+0x77/0xa0 fs/namei.c:4439
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
entry_SYSENTER_compat_after_hwframe+0x70/0x82

Uninit was created at:
slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:716
slab_alloc_node mm/slub.c:3451 [inline]
__kmem_cache_alloc_node+0x4ff/0x8b0 mm/slub.c:3490
kmalloc_trace+0x51/0x200 mm/slab_common.c:1057
kmalloc include/linux/slab.h:559 [inline]
udf_fiiter_find_entry+0x213/0xa60 fs/udf/namei.c:66
udf_unlink+0x80/0x920 fs/udf/namei.c:547
vfs_unlink+0x66f/0xa20 fs/namei.c:4327
do_unlinkat+0x3fa/0xed0 fs/namei.c:4393
__do_sys_unlink fs/namei.c:4441 [inline]
__se_sys_unlink fs/namei.c:4439 [inline]
__ia32_sys_unlink+0x77/0xa0 fs/namei.c:4439
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
entry_SYSENTER_compat_after_hwframe+0x70/0x82

CPU: 1 PID: 5699 Comm: syz-executor.2 Not tainted 6.4.0-rc7-syzkaller-ge6bc8833d80f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
=====================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to change bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup