CVE-2026-53136drm/amd/display: Clamp VBIOS HDMI retimer register count to array size

Official description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Clamp VBIOS HDMI retimer register count to array size [Why & How] The VBIOS integrated info tables (v1_11 and v2_1) contain HdmiRegNum and Hdmi6GRegNum fields that are used as loop bounds when copying retimer I2C register settings into fixed-size arrays (dp*_ext_hdmi_reg_settings[9] and dp*_ext_hdmi_6g_reg_settings[3]). These u8 fields are not validated before use, so a malformed VBIOS can specify values up to 255, causing an out-of-bounds heap write during driver probe. Clamp each register count to the destination array size using min_t() before the copy loops, in both get_integrated_info_v11() and get_integrated_info_v2_1(). (cherry picked from commit 5a7f0ef90195940c54b0f5bb85b87da55f038c69)

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/029571d51140650783be4fb98fe7cb4754752086
• https://git.kernel.org/stable/c/5f8b39452fb16f507c9e4d8b4a83ce27e893307c
• https://git.kernel.org/stable/c/4d1c3c26c2ab1842e139e61983395d64bd2e518b
• https://git.kernel.org/stable/c/d6be8e59af412623e3d874be3a048406c0edfe60
• https://git.kernel.org/stable/c/3f32d52ec604c659725d865cf8cc6a17a33f9c6a
• https://git.kernel.org/stable/c/8aaa7e317fbd4beb9c6a9f77aa4cf52fae78b117
• https://git.kernel.org/stable/c/fb0707ce00eef4e2d60c3020e1c0432739703e4a