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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    80383273f7a0 kmsan: silence -Wmissing-prototypes warnings
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=17960fd6480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b63e082c4fda2e77
dashboard link: https://syzkaller.appspot.com/bug?extid=92ef9ee419803871020e
compiler:       clang version 15.0.0 (https://github.com/llvm/llvm-project.git 610139d2d9ce6746b3c617fb3e2f7886272d26ff), 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/f76b21f14e30/disk-80383273.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ac1c985c1983/vmlinux-80383273.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d6710cffdb38/bzImage-80383273.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+92ef9ee419803871020e@xxxxxxxxxxxxxxxxxxxxxxxxx

loop4: detected capacity change from 0 to 1024
=====================================================
BUG: KMSAN: uninit-value in strncmp+0x11b/0x180 lib/string.c:307
 strncmp+0x11b/0x180 lib/string.c:307
 hfsplus_listxattr+0x996/0x1aa0
 vfs_listxattr fs/xattr.c:472 [inline]
 listxattr+0x703/0x780 fs/xattr.c:820
 path_listxattr fs/xattr.c:844 [inline]
 __do_sys_llistxattr fs/xattr.c:862 [inline]
 __se_sys_llistxattr fs/xattr.c:859 [inline]
 __ia32_sys_llistxattr+0x16d/0x300 fs/xattr.c:859
 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+0x33/0x70 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:766 [inline]
 slab_alloc_node mm/slub.c:3452 [inline]
 __kmem_cache_alloc_node+0x71f/0xce0 mm/slub.c:3491
 kmalloc_trace+0x4d/0x1f0 mm/slab_common.c:1062
 kmalloc include/linux/slab.h:580 [inline]
 hfsplus_listxattr+0x4dc/0x1aa0 fs/hfsplus/xattr.c:702
 vfs_listxattr fs/xattr.c:472 [inline]
 listxattr+0x703/0x780 fs/xattr.c:820
 path_listxattr fs/xattr.c:844 [inline]
 __do_sys_llistxattr fs/xattr.c:862 [inline]
 __se_sys_llistxattr fs/xattr.c:859 [inline]
 __ia32_sys_llistxattr+0x16d/0x300 fs/xattr.c:859
 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+0x33/0x70 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

CPU: 1 PID: 11511 Comm: syz-executor.4 Not tainted 6.2.0-rc3-syzkaller-79341-g80383273f7a0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
=====================================================


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