In the Linux kernel, the following vulnerability has been resolved: drm/dp: Fix OOB read when handling Post Cursor2 register The link_status array was not large enough to read...
Date: 2025-02
Affected: linux/linux_kernel
Attack vector: other
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2022-49218
CWE: CWE-125
CVSS: 7.1 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H)

In the Linux kernel, the following vulnerability has been resolved: drm/dp: Fix OOB read when handling Post Cursor2 register The link_status array was not large enough to read the Adjust Request Post Cursor2 register, so remove the common helper function to avoid an OOB read, found with a -Warray-bounds build: drivers/gpu/drm/drm_dp_helper.c: In function 'drm_dp_get_adjust_request_post_cursor': drivers/gpu/drm/drm_dp_helper.c:59:27: error: array subscript 10 is outside array bounds of 'const u8[6]' {aka 'const unsigned char[6]'} [-Werror=array-bounds] 59 | return link_status[r - DP_LANE0_1_STATUS]; | ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/drm_dp_helper.c:147:51: note: while referencing 'link_status' 147 | u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZE], | ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Replace the only user of the helper with an open-coded fetch and decode, similar to drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c.


Mitigations:

Architectural layers (MAESTRO):