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

syzbot
2024-03-06T12:56:19Z

Hello,

syzbot found the following issue on:

HEAD commit: 5ad3cb0ed525 Merge tag 'for-v6.8-rc2' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1687d706180000
kernel config: https://syzkaller.appspot.com/x/.config?x=80c7a82a572c0de3
dashboard link: https://syzkaller.appspot.com/bug?extid=e126b819d8187b282d44
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b865f2727884/disk-5ad3cb0e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b1c7b0d47f5c/vmlinux-5ad3cb0e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/21afab19a0ed/bzImage-5ad3cb0e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e126b819d8187b282d44@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in case_fold fs/hfsplus/unicode.c:23 [inline]
BUG: KMSAN: uninit-value in hfsplus_strcasecmp+0x1ca/0x770 fs/hfsplus/unicode.c:47
case_fold fs/hfsplus/unicode.c:23 [inline]
hfsplus_strcasecmp+0x1ca/0x770 fs/hfsplus/unicode.c:47
hfsplus_cat_case_cmp_key+0xde/0x190 fs/hfsplus/catalog.c:26
hfs_find_rec_by_key+0xb0/0x240 fs/hfsplus/bfind.c:100
__hfsplus_brec_find+0x26b/0x7b0 fs/hfsplus/bfind.c:135
hfsplus_brec_find+0x445/0x970 fs/hfsplus/bfind.c:195
hfsplus_brec_read+0x46/0x1a0 fs/hfsplus/bfind.c:222
hfsplus_fill_super+0x199a/0x26f0 fs/hfsplus/super.c:531
mount_bdev+0x38f/0x510 fs/super.c:1658
hfsplus_mount+0x4d/0x60 fs/hfsplus/super.c:647
legacy_get_tree+0x110/0x290 fs/fs_context.c:662
vfs_get_tree+0xa5/0x560 fs/super.c:1779
do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
path_mount+0x73d/0x1f20 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount+0x725/0x810 fs/namespace.c:3875
__ia32_sys_mount+0xe3/0x150 fs/namespace.c:3875
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0xb5/0x110 arch/x86/entry/common.c:321
do_fast_syscall_32+0x37/0x70 arch/x86/entry/common.c:346
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:384
entry_SYSENTER_compat_after_hwframe+0x70/0x7a

Uninit was created at:
slab_post_alloc_hook mm/slub.c:3819 [inline]
slab_alloc_node mm/slub.c:3860 [inline]
__do_kmalloc_node mm/slub.c:3980 [inline]
__kmalloc+0x919/0xf80 mm/slub.c:3994
kmalloc include/linux/slab.h:594 [inline]
hfsplus_find_init+0x91/0x250 fs/hfsplus/bfind.c:21
hfsplus_fill_super+0x1688/0x26f0 fs/hfsplus/super.c:525
mount_bdev+0x38f/0x510 fs/super.c:1658
hfsplus_mount+0x4d/0x60 fs/hfsplus/super.c:647
legacy_get_tree+0x110/0x290 fs/fs_context.c:662
vfs_get_tree+0xa5/0x560 fs/super.c:1779
do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
path_mount+0x73d/0x1f20 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount+0x725/0x810 fs/namespace.c:3875
__ia32_sys_mount+0xe3/0x150 fs/namespace.c:3875
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0xb5/0x110 arch/x86/entry/common.c:321
do_fast_syscall_32+0x37/0x70 arch/x86/entry/common.c:346
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:384
entry_SYSENTER_compat_after_hwframe+0x70/0x7a

CPU: 0 PID: 5298 Comm: syz-executor.4 Not tainted 6.8.0-rc6-syzkaller-00238-g5ad3cb0ed525 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
=====================================================

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