CVE-2022-49479: mt76: fix tx status related use-after-free race on station removal
In the Linux kernel, the following vulnerability has been resolved:
mt76: fix tx status related use-after-free race on station removal
There is a small race window where ongoing tx activity can lead to a skb getting added to the status tracking idr after that idr has already been cleaned up, which will keep the wcid linked in the status poll list. Fix this by only adding status skbs if the wcid pointer is still assigned in dev->wcid, which gets cleared early by mt76staprercuremove
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.18.5-1 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Compensating control
In mt76, only add TX status SKBs when the WCID pointer is still assigned in dev->wcid; check this before adding to the status-tracking IDR, because mt76_sta_pre_rcu_remove clears the pointer early.
Event History
Frequently Asked Questions
What is the severity of CVE-2022-49479?
CVE-2022-49479 is classified with a medium severity due to its potential impact on system stability.
How does CVE-2022-49479 affect the Linux Kernel?
CVE-2022-49479 affects the Linux Kernel by introducing a use-after-free race condition related to ongoing transmission activities.
How do I fix CVE-2022-49479?
To fix CVE-2022-49479, update the Linux Kernel to version 5.17.14 or newer.
Which versions of the Linux Kernel are affected by CVE-2022-49479?
CVE-2022-49479 affects Linux Kernel versions from 5.16 to 5.18.3.
What systems are vulnerable to CVE-2022-49479?
Systems running affected versions of the Linux Kernel are vulnerable to CVE-2022-49479.