Bug 2492714 (CVE-2026-53137)

Summary: CVE-2026-53137 kernel: drm/amd/display: Clamp HDMI HDCP2 rx_id_list read to buffer size
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's drm/amd/display component. A malicious HDMI repeater could exploit this vulnerability during HDCP 2.x repeater authentication by sending a message size larger than the allocated buffer. This could lead to an out-of-bounds write, potentially causing a denial of service or other unpredictable system behavior.
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Description OSIDB Bzimport 2026-06-25 10:01:57 UTC 
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)
Comment 1 Mauro Matteo Cascella 2026-06-26 09:44:07 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062543-CVE-2026-53137-e711@gregkh/T