hfsplus: fix KMSAN uninit-value issue in hfsplus_delete_cat()
CVE: CVE-2025-40351
Component: kernel
Severity: Low
CVSS v3: 5.6/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Release date: 2025-12-16T00:00:00+00:00

In the Linux kernel, the following vulnerability has been resolved:

hfsplus: fix KMSAN uninit-value issue in hfsplus_delete_cat()

The syzbot reported issue in hfsplus_delete_cat():

[   70.682285][ T9333] =====================================================
[   70.682943][ T9333] BUG: KMSAN: uninit-value in hfsplus_subfolders_dec+0x1d7/0x220
[   70.683640][ T9333]  hfsplus_subfolders_dec+0x1d7/0x220
[   70.684141][ T9333]  hfsplus_delete_cat+0x105d/0x12b0
[   70.684621][ T9333]  hfsplus_rmdir+0x13d/0x310
[   70.685048][ T9333]  vfs_rmdir+0x5ba/0x810
[   70.685447][ T9333]  do_rmdir+0x964/0xea0
[   70.685833][ T9333]  __x64_sys_rmdir+0x71/0xb0
[   70.686260][ T9333]  x64_sys_call+0xcd8/0x3cf0
[   70.686695][ T9333]  do_syscall_64+0xd9/0x1d0
[   70.687119][ T9333]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.687646][ T9333]
[   70.687856][ T9333] Uninit was stored to memory at:
[   70.688311][ T9333]  hfsplus_subfolders_inc+0x1c2/0x1d0
[   70.688779][ T9333]  hfsplus_create_cat+0x148e/0x1800
[   70.689231][ T9333]  hfsplus_mknod+0x27f/0x600
[   70.689730][ T9333]  hfsplus_mkdir+0x5a/0x70
[   70.690146][ T9333]  vfs_mkdir+0x483/0x7a0
[   70.690545][ T9333]  do_mkdirat+0x3f2/0xd30
[   70.690944][ T9333]  __x64_sys_mkdir+0x9a/0xf0
[   70.691380][ T9333]  x64_sys_call+0x2f89/0x3cf0
[   70.691816][ T9333]  do_syscall_64+0xd9/0x1d0
[   70.692229][ T9333]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.692773][ T9333]
[   70.692990][ T9333] Uninit was stored to memory at:
[   70.693469][ T9333]  hfsplus_subfolders_inc+0x1c2/0x1d0
[   70.693960][ T9333]  hfsplus_create_cat+0x148e/0x1800
[   70.694438][ T9333]  hfsplus_fill_super+0x21c1/0x2700
[   70.694911][ T9333]  mount_bdev+0x37b/0x530
[   70.695320][ T9333]  hfsplus_mount+0x4d/0x60
[   70.695729][ T9333]  legacy_get_tree+0x113/0x2c0
[   70.696167][ T9333]  vfs_get_tree+0xb3/0x5c0
[   70.696588][ T9333]  do_new_mount+0x73e/0x1630
[   70.697013][ T9333]  path_mount+0x6e3/0x1eb0
[   70.697425][ T9333]  __se_sys_mount+0x733/0x830
[   70.697857][ T9333]  __x64_sys_mount+0xe4/0x150
[   70.698269][ T9333]  x64_sys_call+0x2691/0x3cf0
[   70.698704][ T9333]  do_syscall_64+0xd9/0x1d0
[   70.699117][ T9333]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.699730][ T9333]
[   70.699946][ T9333] Uninit was created at:
[   70.700378][ T9333]  __alloc_pages_noprof+0x714/0xe60
[   70.700843][ T9333]  alloc_pages_mpol_noprof+0x2a2/0x9b0
[   70.701331][ T9333]  alloc_pages_noprof+0xf8/0x1f0
[   70.701774][ T9333]  allocate_slab+0x30e/0x1390
[   70.702194][ T9333]  ___slab_alloc+0x1049/0x33a0
[   70.702635][ T9333]  kmem_cache_alloc_lru_noprof+0x5ce/0xb20
[   70.703153][ T9333]  hfsplus_alloc_inode+0x5a/0xd0
[   70.703598][ T9333]  alloc_inode+0x82/0x490
[   70.703984][ T9333]  iget_locked+0x22e/0x1320
[   70.704428][ T9333]  hfsplus_iget+0x5c/0xba0
[   70.704827][ T9333]  hfsplus_btree_open+0x135/0x1dd0
[   70.705291][ T9333]  hfsplus_fill_super+0x1132/0x2700
[   70.705776][ T9333]  mount_bdev+0x37b/0x530
[   70.706171][ T9333]  hfsplus_mount+0x4d/0x60
[   70.706579][ T9333]  legacy_get_tree+0x113/0x2c0
[   70.707019][ T9333]  vfs_get_tree+0xb3/0x5c0
[   70.707444][ T9333]  do_new_mount+0x73e/0x1630
[   70.707865][ T9333]  path_mount+0x6e3/0x1eb0
[   70.708270][ T9333]  __se_sys_mount+0x733/0x830
[   70.708711][ T9333]  __x64_sys_mount+0xe4/0x150
[   70.709158][ T9333]  x64_sys_call+0x2691/0x3cf0
[   70.709630][ T9333]  do_syscall_64+0xd9/0x1d0
[   70.710053][ T9333]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.710611][ T9333]
[   70.710842][ T9333] CPU: 3 UID: 0 PID: 9333 Comm: repro Not tainted 6.12.0-rc6-dirty #17
[   70.711568][ T9333] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   70.712490][ T9333] =====================================================
[   70.713085][ T9333] Disabling lock debugging due to kernel taint
[   70.713618][ T9333] Kernel panic - not syncing: kmsan.panic set ...
[   70.714159][ T9333] 
---truncated---


Remediation: