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.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2022-55481 | 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. |
Wed, 19 Nov 2025 13:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-125 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Metrics |
cvssV3_1
|
cvssV3_1
|
Fri, 20 Jun 2025 02:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Wed, 18 Jun 2025 11:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | drm/fb-helper: Fix out-of-bounds access | |
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T19:15:09.235Z
Reserved: 2025-06-18T10:57:27.430Z
Link: CVE-2022-50221
No data.
Status : Analyzed
Published: 2025-06-18T11:15:53.090
Modified: 2025-11-19T12:58:57.203
Link: CVE-2022-50221
OpenCVE Enrichment
Updated: 2025-06-23T08:53:47Z
EUVD