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

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    8d025e2092e2 Merge tag 'erofs-for-6.9-rc2-fixes' of git://..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=14fa8019180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e2599baf258ef795
dashboard link: https://syzkaller.appspot.com/bug?extid=e126b819d8187b282d44
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=105065c6180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1034025e180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5ccde1a19e22/disk-8d025e20.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/45420817e7d9/vmlinux-8d025e20.xz
kernel image: https://storage.googleapis.com/syzbot-assets/354bdafd8c8f/bzImage-8d025e20.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/417a5560bbaa/mount_0.gz

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

loop0: detected capacity change from 0 to 1024
=====================================================
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+0xb1/0x240 fs/hfsplus/bfind.c:100
 __hfsplus_brec_find+0x26f/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+0x199e/0x2700 fs/hfsplus/super.c:531
 mount_bdev+0x397/0x520 fs/super.c:1676
 hfsplus_mount+0x4d/0x60 fs/hfsplus/super.c:647
 legacy_get_tree+0x114/0x290 fs/fs_context.c:662
 vfs_get_tree+0xa7/0x570 fs/super.c:1797
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
 path_mount+0x742/0x1f20 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
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:3804 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 __do_kmalloc_node mm/slub.c:3965 [inline]
 __kmalloc+0x6e4/0x1000 mm/slub.c:3979
 kmalloc include/linux/slab.h:632 [inline]
 hfsplus_find_init+0x91/0x250 fs/hfsplus/bfind.c:21
 hfsplus_fill_super+0x1688/0x2700 fs/hfsplus/super.c:525
 mount_bdev+0x397/0x520 fs/super.c:1676
 hfsplus_mount+0x4d/0x60 fs/hfsplus/super.c:647
 legacy_get_tree+0x114/0x290 fs/fs_context.c:662
 vfs_get_tree+0xa7/0x570 fs/super.c:1797
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
 path_mount+0x742/0x1f20 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
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

CPU: 1 PID: 5017 Comm: syz-executor416 Not tainted 6.9.0-rc1-syzkaller-00061-g8d025e2092e2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
=====================================================


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