CVE-2026-53137

Description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Clamp HDMI HDCP2 rx_id_list read to buffer size [Why & How] During HDCP 2.x repeater authentication over HDMI, the driver reads the sink's RxStatus register and extracts a 10-bit message size field (max value 1023). This value is used as the read length for the ReceiverID list without being clamped to the size of the destination buffer rx_id_list[177]. A malicious HDMI repeater could advertise a message size larger than the buffer, causing an out-of-bounds write during the I2C read. Clamp the read length in mod_hdcp_read_rx_id_list() to the size of the rx_id_list buffer, matching the approach already used in the DP branch. (cherry picked from commit 229212219e4247d9486f8ba41ef087358490be09)

References

• https://git.kernel.org/stable/c/1906064d50d194a145486e5caf3db3e708b6f6ef
• https://git.kernel.org/stable/c/3c4444aec06c74fbc05661f370954ac814963c38
• https://git.kernel.org/stable/c/79e0273272a05fb26f9b1e55bf1a52eefc3b7b35
• https://git.kernel.org/stable/c/91fb41218c413989d8b6c837748751454b452d68
• https://git.kernel.org/stable/c/964e50ef7b8f09815a7d05b8326af700f8d5bc96