Bug 2426123 (CVE-2022-50829)

Summary: CVE-2022-50829 kernel: wifi: ath9k: hif_usb: Fix use-after-free in ath9k_hif_usb_reg_in_cb()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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A flaw was found in the ath9k USB Wi-Fi driver in the Linux kernel. In certain conditions within the ath9k_hif_usb_reg_in_cb() path, a socket buffer (skb) may be freed prematurely and then freed again on an error path, leading to a use-after-free condition. Additionally, failure to allocate a new skb can result in the URB context becoming NULL, with the associated buffer not being released, causing a memory leak.
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Description OSIDB Bzimport 2025-12-30 13:10:41 UTC 
In the Linux kernel, the following vulnerability has been resolved:

wifi: ath9k: hif_usb: Fix use-after-free in ath9k_hif_usb_reg_in_cb()

It is possible that skb is freed in ath9k_htc_rx_msg(), then
usb_submit_urb() fails and we try to free skb again. It causes
use-after-free bug. Moreover, if alloc_skb() fails, urb->context becomes
NULL but rx_buf is not freed and there can be a memory leak.

The patch removes unnecessary nskb and makes skb processing more clear: it
is supposed that ath9k_htc_rx_msg() either frees old skb or passes its
managing to another callback function.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Comment 1 Alexander B 2025-12-31 07:30:30 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025123015-CVE-2022-50829-2142@gregkh/T