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

syzbot
2024-10-22T22:07:03Z

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: 0 UID: 0 PID: 6057 Comm: syz.0.15 Not tainted 6.12.0-rc4-syzkaller-gc2ee9f594da8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
=====================================================

Tested on:

commit: c2ee9f59 KVM: selftests: Fix build on on non-x86 archi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11d8ca5f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=fa3d7fc2fd6ea40d
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.