CVE-2025-39818

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

HID: intel-thc-hid: intel-thc: Fix incorrect pointer arithmetic in I2C regs save

Improper use of secondary pointer (&dev->i2c_subip_regs) caused kernel crash and out-of-bounds error:

BUG: KASAN: slab-out-of-bounds in _regmap_bulk_read+0x449/0x510 Write of size 4 at addr ffff888136005dc0 by task kworker/u33:5/5107

CPU: 3 UID: 0 PID: 5107 Comm: kworker/u33:5 Not tainted 6.16.0+ #3 PREEMPT(voluntary) Workqueue: async async_run_entry_fn Call Trace: <TASK> dump_stack_lvl+0x76/0xa0 print_report+0xd1/0x660 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? kasan_complete_mode_report_info+0x26/0x200 kasan_report+0xe1/0x120 ? _regmap_bulk_read+0x449/0x510 ? _regmap_bulk_read+0x449/0x510 __asan_report_store4_noabort+0x17/0x30 _regmap_bulk_read+0x449/0x510 ? __pfx__regmap_bulk_read+0x10/0x10 regmap_bulk_read+0x270/0x3d0 pio_complete+0x1ee/0x2c0 [intel_thc] ? __pfx_pio_complete+0x10/0x10 [intel_thc] ? __pfx_pio_wait+0x10/0x10 [intel_thc] ? regmap_update_bits_base+0x13b/0x1f0 thc_i2c_subip_pio_read+0x117/0x270 [intel_thc] thc_i2c_subip_regs_save+0xc2/0x140 [intel_thc] ? __pfx_thc_i2c_subip_regs_save+0x10/0x10 [intel_thc] [...] The buggy address belongs to the object at ffff888136005d00 which belongs to the cache kmalloc-rnd-12-192 of size 192 The buggy address is located 0 bytes to the right of allocated 192-byte region [ffff888136005d00, ffff888136005dc0)

Replaced with direct array indexing (&dev->i2c_subip_regs[i]) to ensure safe memory access.

This vulnerability is rated as Moderate because exploitation requires local access on systems equipped with specific Intel Touch Host Controller hardware, limiting the attack surface to physical platforms or environments exposing this device. While an out-of-bounds write can result in a system crash or denial of service, remote triggering without local access or appropriate device interaction is not possible. Typical enterprise server installations that lack Intel touch interface peripherals remain effectively unaffected in standard operating scenarios.

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.