CVE-2025-38713

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

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

The hfsplus_readdir() method is capable to crash by calling hfsplus_uni2asc():

[ 667.121659][ T9805] ================================================================== [ 667.122651][ T9805] BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0x902/0xa10 [ 667.123627][ T9805] Read of size 2 at addr ffff88802592f40c by task repro/9805 [ 667.124578][ T9805] [ 667.124876][ T9805] CPU: 3 UID: 0 PID: 9805 Comm: repro Not tainted 6.16.0-rc3 #1 PREEMPT(full) [ 667.124886][ T9805] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 667.124890][ T9805] Call Trace: [ 667.124893][ T9805] <TASK> [ 667.124896][ T9805] dump_stack_lvl+0x10e/0x1f0 [ 667.124911][ T9805] print_report+0xd0/0x660 [ 667.124920][ T9805] ? __virt_addr_valid+0x81/0x610 [ 667.124928][ T9805] ? __phys_addr+0xe8/0x180 [ 667.124934][ T9805] ? hfsplus_uni2asc+0x902/0xa10 [ 667.124942][ T9805] kasan_report+0xc6/0x100 [ 667.124950][ T9805] ? hfsplus_uni2asc+0x902/0xa10 [ 667.124959][ T9805] hfsplus_uni2asc+0x902/0xa10 [ 667.124966][ T9805] ? hfsplus_bnode_read+0x14b/0x360 [ 667.124974][ T9805] hfsplus_readdir+0x845/0xfc0 [ 667.124984][ T9805] ? __pfx_hfsplus_readdir+0x10/0x10 [ 667.124994][ T9805] ? stack_trace_save+0x8e/0xc0 [ 667.125008][ T9805] ? iterate_dir+0x18b/0xb20 [ 667.125015][ T9805] ? trace_lock_acquire+0x85/0xd0 [ 667.125022][ T9805] ? lock_acquire+0x30/0x80 [ 667.125029][ T9805] ? iterate_dir+0x18b/0xb20 [ 667.125037][ T9805] ? down_read_killable+0x1ed/0x4c0 [ 667.125044][ T9805] ? putname+0x154/0x1a0 [ 667.125051][ T9805] ? __pfx_down_read_killable+0x10/0x10 [ 667.125058][ T9805] ? apparmor_file_permission+0x239/0x3e0 [ 667.125069][ T9805] iterate_dir+0x296/0xb20 [ 667.125076][ T9805] __x64_sys_getdents64+0x13c/0x2c0 [ 667.125084][ T9805] ? __pfx___x64_sys_getdents64+0x10/0x10 [ 667.125091][ T9805] ? __x64_sys_openat+0x141/0x200 [ 667.125126][ T9805] ? __pfx_filldir64+0x10/0x10 [ 667.125134][ T9805] ? do_user_addr_fault+0x7fe/0x12f0 [ 667.125143][ T9805] do_syscall_64+0xc9/0x480 [ 667.125151][ T9805] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 667.125158][ T9805] RIP: 0033:0x7fa8753b2fc9 [ 667.125164][ T9805] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 48 [ 667.125172][ T9805] RSP: 002b:00007ffe96f8e0f8 EFLAGS: 00000217 ORIG_RAX: 00000000000000d9 [ 667.125181][ T9805] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa8753b2fc9 [ 667.125185][ T9805] RDX: 0000000000000400 RSI: 00002000000063c0 RDI: 0000000000000004 [ 667.125190][ T9805] RBP: 00007ffe96f8e110 R08: 00007ffe96f8e110 R09: 00007ffe96f8e110 [ 667.125195][ T9805] R10: 0000000000000000 R11: 0000000000000217 R12: 0000556b1e3b4260 [ 667.125199][ T9805] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 667.125207][ T9805] </TASK> [ 667.125210][ T9805] [ 667.145632][ T9805] Allocated by task 9805: [ 667.145991][ T9805] kasan_save_stack+0x20/0x40 [ 667.146352][ T9805] kasan_save_track+0x14/0x30 [ 667.146717][ T9805] __kasan_kmalloc+0xaa/0xb0 [ 667.147065][ T9805] __kmalloc_noprof+0x205/0x550 [ 667.147448][ T9805] hfsplus_find_init+0x95/0x1f0 [ 667.147813][ T9805] hfsplus_readdir+0x220/0xfc0 [ 667.148174][ T9805] iterate_dir+0x296/0xb20 [ 667.148549][ T9805] __x64_sys_getdents64+0x13c/0x2c0 [ 667.148937][ T9805] do_syscall_64+0xc9/0x480 [ 667.149291][ T9805] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 667.149809][ T9805] [ 667.150030][ T9805] The buggy address belongs to the object at ffff88802592f000 [ 667.150030][ T9805] which belongs to the cache kmalloc-2k of size 2048 [ 667.151282][ T9805] The buggy address is located 0 bytes to the right of [ 667.151282][ T9805] allocated 1036-byte region [ffff88802592f000, ffff88802592f40c) [ 667.1 ---truncated---

This vulnerability does not require elevated user privileges to trigger, but does require a corrupted HFS+ filesystem where the length values in the hfsplus_unistr data structures are invalid. This corruption must exist on disk in the filesystem metadata.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.