[syzbot] [hfs?] KMSAN: uninit-value in hfsplus_listxattr (2)

[syzbot <syzbot+01ade747b16e9c8030e0@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    fec50db7033e Linux 6.9-rc3
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1467098d180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=13e7da432565d94c
dashboard link: https://syzkaller.appspot.com/bug?extid=01ade747b16e9c8030e0
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=138f4d8d180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15763da9180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/901017b36ccc/disk-fec50db7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/16bfcf5618d3/vmlinux-fec50db7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/dc9c5a1e7d02/bzImage-fec50db7.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/4dff8cc527ea/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+01ade747b16e9c8030e0@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 1024
=====================================================
BUG: KMSAN: uninit-value in strncmp+0x11e/0x180 lib/string.c:291
 strncmp+0x11e/0x180 lib/string.c:291
 hfsplus_listxattr+0x97d/0x1a60
 vfs_listxattr fs/xattr.c:493 [inline]
 listxattr+0x1f3/0x6b0 fs/xattr.c:840
 path_listxattr fs/xattr.c:864 [inline]
 __do_sys_listxattr fs/xattr.c:876 [inline]
 __se_sys_listxattr fs/xattr.c:873 [inline]
 __x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:3804 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmalloc_trace+0x578/0xba0 mm/slub.c:3992
 kmalloc include/linux/slab.h:628 [inline]
 hfsplus_listxattr+0x4cc/0x1a60 fs/hfsplus/xattr.c:701
 vfs_listxattr fs/xattr.c:493 [inline]
 listxattr+0x1f3/0x6b0 fs/xattr.c:840
 path_listxattr fs/xattr.c:864 [inline]
 __do_sys_listxattr fs/xattr.c:876 [inline]
 __se_sys_listxattr fs/xattr.c:873 [inline]
 __x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

CPU: 0 PID: 5019 Comm: syz-executor940 Not tainted 6.9.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
=====================================================


---
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 syzkaller@googlegroups.com.

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

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

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.

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

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

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