Bug 2492829 (CVE-2026-53135)

Summary: CVE-2026-53135 kernel: drm/amd/display: Fix NULL deref and buffer over-read in SDP debugfs
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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A flaw was found in the Linux kernel's `drm/amd/display` module. A local user could exploit this vulnerability by writing to the `sdp_message` debugfs node. The system may experience a kernel crash due to a null pointer dereference, leading to a denial of service (DoS). Additionally, the flaw could result in a buffer over-read, potentially exposing sensitive information or leading to further instability.
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Description OSIDB Bzimport 2026-06-25 10:07:57 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Fix NULL deref and buffer over-read in SDP debugfs

[Why & How]
dp_sdp_message_debugfs_write() dereferences connector->base.state->crtc
without checking for NULL. A connector can be connected but not bound to
any CRTC (e.g. after hot-plug before the next atomic commit), causing a
kernel crash when writing to the sdp_message debugfs node.

The function also ignores the user-provided size argument and always
passes 36 bytes to copy_from_user(), reading past the user buffer when
size < 36.

Fix both issues by:
- Returning -ENODEV when connector->base.state or state->crtc is NULL
- Clamping write_size to min(size, sizeof(data))

(cherry picked from commit 6ab4c36a522842ff70474a1c0af2e40e50fc8300)
Comment 1 TEJ RATHI 2026-06-26 06:53:00 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062542-CVE-2026-53135-2c56@gregkh/T