CVE-2022-50221
Description
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 min_off/max_off in drm_fb_helper_deferred_io(). This avoids confusion with the macros of the same name.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2022-50221
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2022-50221.html
Vendor advisory: redhat — https://access.redhat.com/errata/RHSA-2023:2458
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| rhel | 9 | fixed | |
| sles | affected | | |
| debian | bookworm | fixed | 6.0.2-1 |
| debian | bullseye | fixed | 0 |
| debian | forky | fixed | 6.0.2-1 |
| debian | sid | fixed | 6.0.2-1 |
| debian | trixie | fixed | 6.0.2-1 |
References
Verify integrity in audit chain (admin only). AS-IS.