CVE-2023-53715

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

wifi: brcmfmac: cfg80211: Pass the PMK in binary instead of hex

Apparently the hex passphrase mechanism does not work on newer chips/firmware (e.g. BCM4387). It seems there was a simple way of passing it in binary all along, so use that and avoid the hexification.

OpenBSD has been doing it like this from the beginning, so this should work on all chips.

Also clear the structure before setting the PMK. This was leaking uninitialized stack contents to the device.

Fixes an information leak of uninitialized stack bytes in brcmfmac when setting the PMK: the structure wasn’t zeroed, so garbage beyond the key could be sent to the Wi-Fi device firmware. Impact is limited to exposure of kernel memory to a local peripheral/firmware (where exploitation generally requires a malicious/compromised Wi-Fi chipset/firmware or bus snooping during PMK provisioning). For the CVSS the PR:H because an attacker effectively needs control over the device/firmware path.

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.