CVE-2022-50240: android: binder: stop saving a pointer to the VMA
In the Linux kernel, the following vulnerability has been resolved:
android: binder: stop saving a pointer to the VMA
Do not record a pointer to a VMA outside of the mmaplock for later use. This is unsafe and there are a number of failure paths after the recorded VMA pointer may be freed during setup. There is no callback to the driver to clear the saved pointer from generic mm code. Furthermore, the VMA pointer may become stale if any number of VMA operations end up freeing the VMA so saving it was fragile to being with.
Instead, change the binderalloc struct to record the start address of the VMA and use vmalookup() to get the vma when needed. Add lockdep mmaplock checks on updates to the vma pointer to ensure the lock is held and depend on that lock for synchronization of readers and writers - which was already the case anyways, so the smpwmb()/smprmb() was not necessary.
[akpm@linux-foundation.org: fix drivers/android/binderallocselftest.c]
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2022-50240?
CVE-2022-50240 has been classified as a high-severity vulnerability due to its potential impact on system stability and security.
How do I fix CVE-2022-50240?
To fix CVE-2022-50240, you should update your Linux kernel to the latest stable version containing the patch for this vulnerability.
What systems are affected by CVE-2022-50240?
CVE-2022-50240 affects the Linux kernel, particularly those instances where the binder is used.
What type of vulnerability is CVE-2022-50240?
CVE-2022-50240 is a use-after-free (UAF) vulnerability in the Linux kernel related to the binder mechanism.
Is CVE-2022-50240 being actively exploited?
As of now, there is no public indication that CVE-2022-50240 is being actively exploited in the wild, but it is advised to apply patches timely.