CVE-2023-53641

/// Technical description

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

wifi: ath9k: hif_usb: fix memory leak of remain_skbs

hif_dev->remain_skb is allocated and used exclusively in

ath9k_hif_usb_rx_stream(). It is implied that an allocated remain_skb is

processed and subsequently freed (in error paths) only during the next

call of ath9k_hif_usb_rx_stream().

So, if the urbs are deallocated between those two calls due to the device

deinitialization or suspend, it is possible that ath9k_hif_usb_rx_stream()

is not called next time and the allocated remain_skb is leaked. Our local

Syzkaller instance was able to trigger that.

remain_skb makes sense when receiving two consecutive urbs which are

logically linked together, i.e. a specific data field from the first skb

indicates a cached skb to be allocated, memcpy'd with some data and

subsequently processed in the next call to ath9k_hif_usb_rx_stream(). Urbs

deallocation supposedly makes that link irrelevant so we need to free the

cached skb i

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References