CVE-2024-56539

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

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

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 "wildcardssidtlv->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 mwifiexscannetworks+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 WILDCARDSSIDTLVMAXSIZE 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.