CVE-2025-38348

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

wifi: p54: prevent buffer-overflow in p54_rx_eeprom_readback()

Robert Morris reported:

|If a malicious USB device pretends to be an Intersil p54 wifi |interface and generates an eeprom_readback message with a large |eeprom->v1.len, p54_rx_eeprom_readback() will copy data from the |message beyond the end of priv->eeprom. | |static void p54_rx_eeprom_readback(struct p54_common *priv, | struct sk_buff *skb) |{ | struct p54_hdr *hdr = (struct p54_hdr *) skb->data; | struct p54_eeprom_lm86 *eeprom = (struct p54_eeprom_lm86 *) hdr->data; | | if (priv->fw_var >= 0x509) { | memcpy(priv->eeprom, eeprom->v2.data, | le16_to_cpu(eeprom->v2.len)); | } else { | memcpy(priv->eeprom, eeprom->v1.data, | le16_to_cpu(eeprom->v1.len)); | } | […]

The eeprom->v{1,2}.len is set by the driver in p54_download_eeprom(). The device is supposed to provide the same length back to the driver. But yes, its possible (like shown in the report) to alter the value to something that causes a crash/panic due to overrun.

This patch addresses the issue by adding the size to the common device context, so p54_rx_eeprom_readback no longer relies on possibly tampered values… That said, it also checks if the firmware altered the value and no longer copies them.

The one, small saving grace is: Before the driver tries to read the eeprom, it needs to upload >a< firmware. the vendor firmware has a proprietary license and as a reason, it is not present on most distributions by default.

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/0e4dc150423b829c35cbcf399481ca11594fc036
• https://git.kernel.org/stable/c/12134f79e53eb56b0b0b7447fa0c512acf6a8422
• https://git.kernel.org/stable/c/1f7f8168abe8cbe845ab8bb557228d44784a6b57
• https://git.kernel.org/stable/c/6d05390d20f110de37d051a3e063ef0a542d01fb
• https://git.kernel.org/stable/c/714afb4c38edd19a057d519c1f9c5d164b43de94
• https://git.kernel.org/stable/c/9701f842031b825e2fd5f22d064166f8f13f6e4d
• https://git.kernel.org/stable/c/da1b9a55ff116cb040528ef664c70a4eec03ae99
• https://git.kernel.org/stable/c/f39b2f8c1549a539846e083790fad396ef6cd802
• https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
• https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html