Vulnerabilities > CVE-2021-47111 - Use After Free vulnerability in Linux Kernel
Attack vector
LOCAL Attack complexity
LOW Privileges required
LOW Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
In the Linux kernel, the following vulnerability has been resolved: xen-netback: take a reference to the RX task thread Do this in order to prevent the task from being freed if the thread returns (which can be triggered by the frontend) before the call to kthread_stop done as part of the backend tear down. Not taking the reference will lead to a use-after-free in that scenario. Such reference was taken before but dropped as part of the rework done in 2ac061ce97f4. Reintroduce the reference taking and add a comment this time explaining why it's needed. This is XSA-374 / CVE-2021-28691.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
References
- https://git.kernel.org/stable/c/107866a8eb0b664675a260f1ba0655010fac1e08
- https://git.kernel.org/stable/c/107866a8eb0b664675a260f1ba0655010fac1e08
- https://git.kernel.org/stable/c/6b53db8c4c14b4e7256f058d202908b54a7b85b4
- https://git.kernel.org/stable/c/6b53db8c4c14b4e7256f058d202908b54a7b85b4
- https://git.kernel.org/stable/c/caec9bcaeb1a5f03f2d406305355c853af10c13e
- https://git.kernel.org/stable/c/caec9bcaeb1a5f03f2d406305355c853af10c13e