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

[syzbot <syzbot+2e6fb1f89ce5e13cd02d@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KMSAN: uninit-value in hfs_free_fork

loop0: detected capacity change from 0 to 64
=====================================================
BUG: KMSAN: uninit-value in __hfs_ext_read_extent fs/hfs/extent.c:160 [inline]
BUG: KMSAN: uninit-value in hfs_free_fork+0x6b4/0xa50 fs/hfs/extent.c:320
 __hfs_ext_read_extent fs/hfs/extent.c:160 [inline]
 hfs_free_fork+0x6b4/0xa50 fs/hfs/extent.c:320
 hfs_cat_delete+0x501/0xb90 fs/hfs/catalog.c:247
 hfs_remove+0x16a/0x2f0 fs/hfs/dir.c:262
 vfs_unlink+0x676/0xa90 fs/namei.c:4469
 do_unlinkat+0x823/0xe10 fs/namei.c:4533
 __do_sys_unlink fs/namei.c:4581 [inline]
 __se_sys_unlink fs/namei.c:4579 [inline]
 __x64_sys_unlink+0x76/0xa0 fs/namei.c:4579
 x64_sys_call+0x30d3/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4091 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 __do_kmalloc_node mm/slub.c:4263 [inline]
 __kmalloc_noprof+0x661/0xf30 mm/slub.c:4276
 kmalloc_noprof include/linux/slab.h:882 [inline]
 hfs_find_init+0x91/0x250 fs/hfs/bfind.c:21
 hfs_free_fork+0x3bb/0xa50 fs/hfs/extent.c:316
 hfs_cat_delete+0x501/0xb90 fs/hfs/catalog.c:247
 hfs_remove+0x16a/0x2f0 fs/hfs/dir.c:262
 vfs_unlink+0x676/0xa90 fs/namei.c:4469
 do_unlinkat+0x823/0xe10 fs/namei.c:4533
 __do_sys_unlink fs/namei.c:4581 [inline]
 __se_sys_unlink fs/namei.c:4579 [inline]
 __x64_sys_unlink+0x76/0xa0 fs/namei.c:4579
 x64_sys_call+0x30d3/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 6013 Comm: syz.0.15 Not tainted 6.12.0-rc7-syzkaller-g2d5404caa8c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
=====================================================


Tested on:

commit:         2d5404ca Linux 6.12-rc7
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12cd38c0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d1e659028faecb9
dashboard link: https://syzkaller.appspot.com/bug?extid=2e6fb1f89ce5e13cd02d
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.