CVE-2024-56539 wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_config_scan()

What is CVE-2024-56539?

CVE-2024-56539 is a medium-severity memory corruption vulnerability in Linux kernel, published on 27 Dec 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_config_scan()

Replace one-element array with a flexible-array member in `struct mwifiex_ie_types_wildcard_ssid_params` to fix the following warning on a MT8173 Chromebook (mt8173-elm-hana):

[ 356.775250] ------------[ cut here ]------------ [ 356.784543] memcpy: detected field-spanning write (size 6) of single field "wildcard_ssid_tlv->ssid" at drivers/net/wireless/marvell/mwifiex/scan.c:904 (size 1) [ 356.813403] WARNING: CPU: 3 PID: 742 at drivers/net/wireless/marvell/mwifiex/scan.c:904 mwifiex_scan_networks+0x4fc/0xf28 [mwifiex]

The "(size 6)" above is exactly the length of the SSID of the network this device was connected to. The source of the warning looks like:

ssid_len = user_scan_in->ssid_list[i].ssid_len; [...] memcpy(wildcard_ssid_tlv->ssid, user_scan_in->ssid_list[i].ssid, ssid_len);

There is a #define WILDCARD_SSID_TLV_MAX_SIZE that uses sizeof() on this struct, but it already didn't account for the size of the one-element array, so it doesn't need to be changed.

Which versions are affected by CVE-2024-56539?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-56539?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2024-56539 being exploited?

There is no known exploitation of CVE-2024-56539 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2024-56539, DEBIAN-CVE-2024-56539, GHSA-3598-6xhq-v9q3, UBUNTU-CVE-2024-56539.