CVE-2025-39809

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

HID: intel-thc-hid: intel-quicki2c: Fix ACPI dsd ICRS/ISUB length

The QuickI2C ACPI _DSD methods return ICRS and ISUB data with a trailing byte, making the actual length is one more byte than the structs defined.

It caused stack-out-of-bounds and kernel crash:

kernel: BUG: KASAN: stack-out-of-bounds in quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c] kernel: Write of size 12 at addr ffff888106d1f900 by task kworker/u33:2/75 kernel: kernel: CPU: 3 UID: 0 PID: 75 Comm: kworker/u33:2 Not tainted 6.16.0+ #3 PREEMPT(voluntary) kernel: Workqueue: async async_run_entry_fn kernel: Call Trace: kernel: kernel: dump_stack_lvl+0x76/0xa0 kernel: print_report+0xd1/0x660 kernel: ? __pfx__raw_spin_lock_irqsave+0x10/0x10 kernel: ? __kasan_slab_free+0x5d/0x80 kernel: ? kasan_addr_to_slab+0xd/0xb0 kernel: kasan_report+0xe1/0x120 kernel: ? quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c] kernel: ? quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c] kernel: kasan_check_range+0x11c/0x200 kernel: __asan_memcpy+0x3b/0x80 kernel: quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c] kernel: ? __pfx_quicki2c_acpi_get_dsd_property.constprop.0+0x10/0x10 [intel_quicki2c] kernel: quicki2c_get_acpi_resources+0x237/0x730 [intel_quicki2c] […] kernel: kernel: kernel: The buggy address belongs to stack of task kworker/u33:2/75 kernel: and is located at offset 48 in frame: kernel: quicki2c_get_acpi_resources+0x0/0x730 [intel_quicki2c] kernel: kernel: This frame has 3 objects: kernel: [32, 36) hid_desc_addr kernel: [48, 59) i2c_param kernel: [80, 224) i2c_config

ACPI DSD methods return:

_SB.PC00.THC0.ICRS Buffer 000000003fdc947b 001 Len 0C = 0A 00 80 1A 06 00 00 00 00 00 00 00 _SB.PC00.THC0.ISUB Buffer 00000000f2fcbdc4 001 Len 91 = 00 00 00 00 00 00 00 00 00 00 00 00

Adding reserved padding to quicki2c_subip_acpi_parameter/config.

Weakness

The product writes data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

• For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer.

• Be wary that a language’s interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

• Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.

• Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.

• D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.

• Consider adhering to the following rules when allocating and managing an application’s memory:

• Run or compile the software using features or extensions that randomly arrange the positions of a program’s executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.

• Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as “rebasing” (for Windows) and “prelinking” (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.

• For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].

• Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment.

• For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].

References

• https://git.kernel.org/stable/c/1db9df89a213318a48d958385dc1b17b379dc32b
• https://git.kernel.org/stable/c/4adce86d4b13d15dec7810967839b931b1598700