[syzbot] KMSAN: uninit-value in hfsplus_delete_cat

From: syzbot
Date: Mon Dec 05 2022 - 04:20:00 EST


Hello,

syzbot found the following issue on:

HEAD commit: 49a9a20768f5 kmsan: allow using __msan_instrument_asm_stor..
git tree: https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=1412684d880000
kernel config: https://syzkaller.appspot.com/x/.config?x=d901b2d28729cb6a
dashboard link: https://syzkaller.appspot.com/bug?extid=fdedff847a0e5e84c39f
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/4a944f9f50fb/disk-49a9a207.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a2ec5594e201/vmlinux-49a9a207.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3aafc1a9ba37/bzImage-49a9a207.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fdedff847a0e5e84c39f@xxxxxxxxxxxxxxxxxxxxxxxxx

loop2: detected capacity change from 0 to 1024
=====================================================
BUG: KMSAN: uninit-value in hfsplus_subfolders_dec fs/hfsplus/catalog.c:248 [inline]
BUG: KMSAN: uninit-value in hfsplus_delete_cat+0x1207/0x14d0 fs/hfsplus/catalog.c:419
hfsplus_subfolders_dec fs/hfsplus/catalog.c:248 [inline]
hfsplus_delete_cat+0x1207/0x14d0 fs/hfsplus/catalog.c:419
hfsplus_rmdir+0x141/0x3d0 fs/hfsplus/dir.c:425
hfsplus_rename+0x102/0x2e0 fs/hfsplus/dir.c:545
vfs_rename+0x1e4c/0x2800 fs/namei.c:4779
do_renameat2+0x173d/0x1dc0 fs/namei.c:4930
__do_sys_renameat2 fs/namei.c:4963 [inline]
__se_sys_renameat2 fs/namei.c:4960 [inline]
__ia32_sys_renameat2+0x14b/0x1f0 fs/namei.c:4960
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 stored to memory at:
hfsplus_subfolders_inc fs/hfsplus/catalog.c:232 [inline]
hfsplus_create_cat+0x19e3/0x19f0 fs/hfsplus/catalog.c:314
hfsplus_mknod+0x1fd/0x560 fs/hfsplus/dir.c:494
hfsplus_mkdir+0x54/0x60 fs/hfsplus/dir.c:529
vfs_mkdir+0x62a/0x870 fs/namei.c:4036
do_mkdirat+0x466/0x7b0 fs/namei.c:4061
__do_sys_mkdirat fs/namei.c:4076 [inline]
__se_sys_mkdirat fs/namei.c:4074 [inline]
__ia32_sys_mkdirat+0xc4/0x120 fs/namei.c:4074
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:
__alloc_pages+0x9f1/0xe80 mm/page_alloc.c:5581
alloc_pages+0xaae/0xd80 mm/mempolicy.c:2285
alloc_slab_page mm/slub.c:1794 [inline]
allocate_slab+0x1b5/0x1010 mm/slub.c:1939
new_slab mm/slub.c:1992 [inline]
___slab_alloc+0x10c3/0x2d60 mm/slub.c:3180
__slab_alloc mm/slub.c:3279 [inline]
slab_alloc_node mm/slub.c:3364 [inline]
slab_alloc mm/slub.c:3406 [inline]
__kmem_cache_alloc_lru mm/slub.c:3413 [inline]
kmem_cache_alloc_lru+0x6f3/0xb30 mm/slub.c:3429
alloc_inode_sb include/linux/fs.h:3125 [inline]
hfsplus_alloc_inode+0x56/0xc0 fs/hfsplus/super.c:627
alloc_inode+0x83/0x440 fs/inode.c:259
iget_locked+0x2a1/0xe20 fs/inode.c:1286
hfsplus_iget+0x5f/0xb60 fs/hfsplus/super.c:64
hfsplus_btree_open+0x13b/0x1cf0 fs/hfsplus/btree.c:150
hfsplus_fill_super+0x12b0/0x2a80 fs/hfsplus/super.c:473
mount_bdev+0x508/0x840 fs/super.c:1401
hfsplus_mount+0x49/0x60 fs/hfsplus/super.c:641
legacy_get_tree+0x10c/0x280 fs/fs_context.c:610
vfs_get_tree+0xa1/0x500 fs/super.c:1531
do_new_mount+0x694/0x1580 fs/namespace.c:3040
path_mount+0x71a/0x1eb0 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount+0x734/0x840 fs/namespace.c:3568
__ia32_sys_mount+0xdf/0x140 fs/namespace.c:3568
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: 3898 Comm: syz-executor.2 Not tainted 6.1.0-rc7-syzkaller-63931-g49a9a20768f5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
=====================================================


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