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

hfsplus: fix slab-out-of-bounds read in hfsplus_uni2asc()

BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0xa71/0xb90 fs/hfsplus/unicode.c:186
Read of size 2 at addr ffff8880289ef218 by task syz.6.248/14290

CPU: 0 UID: 0 PID: 14290 Comm: syz.6.248 Not tainted 6.16.4 #1 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x5f0 mm/kasan/report.c:482
kasan_report+0xca/0x100 mm/kasan/report.c:595
hfsplus_uni2asc+0xa71/0xb90 fs/hfsplus/unicode.c:186
hfsplus_listxattr+0x5b6/0xbd0 fs/hfsplus/xattr.c:738
vfs_listxattr+0xbe/0x140 fs/xattr.c:493
listxattr+0xee/0x190 fs/xattr.c:924
filename_listxattr fs/xattr.c:958 [inline]
path_listxattrat+0x143/0x360 fs/xattr.c:988
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcb/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe0e9fae16d
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe0eae67f98 EFLAGS: 00000246 ORIG_RAX: 00000000000000c3
RAX: ffffffffffffffda RBX: 00007fe0ea205fa0 RCX: 00007fe0e9fae16d
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007fe0ea0480f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe0ea206038 R14: 00007fe0ea205fa0 R15: 00007fe0eae48000
</TASK>

Allocated by task 14290:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4333 [inline]
__kmalloc_noprof+0x219/0x540 mm/slub.c:4345
kmalloc_noprof include/linux/slab.h:909 [inline]
hfsplus_find_init+0x95/0x1f0 fs/hfsplus/bfind.c:21
hfsplus_listxattr+0x331/0xbd0 fs/hfsplus/xattr.c:697
vfs_listxattr+0xbe/0x140 fs/xattr.c:493
listxattr+0xee/0x190 fs/xattr.c:924
filename_listxattr fs/xattr.c:958 [inline]
path_listxattrat+0x143/0x360 fs/xattr.c:988
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcb/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

When hfsplus_uni2asc is called from hfsplus_listxattr,
it actually passes in a struct hfsplus_attr_unistr*.
The size of the corresponding structure is different from that of hfsplus_unistr,
so the previous fix (94458781aee6) is insufficient.
The pointer on the unicode buffer is still going beyond the allocated memory.

This patch introduces two warpper functions hfsplus_uni2asc_xattr_str and
hfsplus_uni2asc_str to process two unicode buffers,
struct hfsplus_attr_unistr* and struct hfsplus_unistr* respectively.
When ustrlen value is bigger than the allocated memory size,
the ustrlen value is limited to an safe size.

Metrics

No CVSS v4.0

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00018.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

No data.

No data.

No data.

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/857aefc70d4ae3b9bf1ae67434d27d0f79f80c9e cve-icon cve-icon
https://git.kernel.org/stable/c/bea3e1d4467bcf292c8e54f080353d556d355e26 cve-icon cve-icon
History

Tue, 28 Oct 2025 12:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: hfsplus: fix slab-out-of-bounds read in hfsplus_uni2asc() BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0xa71/0xb90 fs/hfsplus/unicode.c:186 Read of size 2 at addr ffff8880289ef218 by task syz.6.248/14290 CPU: 0 UID: 0 PID: 14290 Comm: syz.6.248 Not tainted 6.16.4 #1 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x5f0 mm/kasan/report.c:482 kasan_report+0xca/0x100 mm/kasan/report.c:595 hfsplus_uni2asc+0xa71/0xb90 fs/hfsplus/unicode.c:186 hfsplus_listxattr+0x5b6/0xbd0 fs/hfsplus/xattr.c:738 vfs_listxattr+0xbe/0x140 fs/xattr.c:493 listxattr+0xee/0x190 fs/xattr.c:924 filename_listxattr fs/xattr.c:958 [inline] path_listxattrat+0x143/0x360 fs/xattr.c:988 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcb/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe0e9fae16d Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe0eae67f98 EFLAGS: 00000246 ORIG_RAX: 00000000000000c3 RAX: ffffffffffffffda RBX: 00007fe0ea205fa0 RCX: 00007fe0e9fae16d RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000 RBP: 00007fe0ea0480f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe0ea206038 R14: 00007fe0ea205fa0 R15: 00007fe0eae48000 </TASK> Allocated by task 14290: kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4333 [inline] __kmalloc_noprof+0x219/0x540 mm/slub.c:4345 kmalloc_noprof include/linux/slab.h:909 [inline] hfsplus_find_init+0x95/0x1f0 fs/hfsplus/bfind.c:21 hfsplus_listxattr+0x331/0xbd0 fs/hfsplus/xattr.c:697 vfs_listxattr+0xbe/0x140 fs/xattr.c:493 listxattr+0xee/0x190 fs/xattr.c:924 filename_listxattr fs/xattr.c:958 [inline] path_listxattrat+0x143/0x360 fs/xattr.c:988 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcb/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f When hfsplus_uni2asc is called from hfsplus_listxattr, it actually passes in a struct hfsplus_attr_unistr*. The size of the corresponding structure is different from that of hfsplus_unistr, so the previous fix (94458781aee6) is insufficient. The pointer on the unicode buffer is still going beyond the allocated memory. This patch introduces two warpper functions hfsplus_uni2asc_xattr_str and hfsplus_uni2asc_str to process two unicode buffers, struct hfsplus_attr_unistr* and struct hfsplus_unistr* respectively. When ustrlen value is bigger than the allocated memory size, the ustrlen value is limited to an safe size.
Title hfsplus: fix slab-out-of-bounds read in hfsplus_uni2asc()
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-10-28T11:48:45.975Z

Reserved: 2025-04-16T07:20:57.161Z

Link: CVE-2025-40082

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-10-28T12:15:42.840

Modified: 2025-10-28T12:15:42.840

Link: CVE-2025-40082

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.