CVE-2022-50221: drm/fb-helper: Fix out-of-bounds access
In the Linux kernel, the following vulnerability has been resolved:
drm/fb-helper: Fix out-of-bounds access
Clip memory range to screen-buffer size to avoid out-of-bounds access in fbdev deferred I/O's damage handling.
Fbdev's deferred I/O can only track pages. From the range of pages, the damage handler computes the clipping rectangle for the display update. If the fbdev screen buffer ends near the beginning of a page, that page could contain more scanlines. The damage handler would then track these non-existing scanlines as dirty and provoke an out-of-bounds access during the screen update. Hence, clip the maximum memory range to the size of the screen buffer.
While at it, rename the variables min/max to minoff/maxoff in drmfbhelperdeferredio(). This avoids confusion with the macros of the same name.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2022-50221?
CVE-2022-50221 is classified as a medium severity vulnerability due to its potential for causing out-of-bounds access.
How do I fix CVE-2022-50221?
To mitigate CVE-2022-50221, ensure you update the Linux kernel to a version that includes the security fix.
What does CVE-2022-50221 affect?
CVE-2022-50221 affects the Linux kernel, specifically the fbdev subsystem handling deferred I/O.
What type of vulnerability is CVE-2022-50221?
CVE-2022-50221 is an out-of-bounds access vulnerability that can lead to potential memory corruption.
Is CVE-2022-50221 present in all Linux kernel versions?
CVE-2022-50221 is not present in the patched versions of the Linux kernel; earlier versions may be affected.