Bug 2492451 (CVE-2026-53058)

Summary: CVE-2026-53058 kernel: drm/bridge: cadence: cdns-mhdp8546-core: Set the mhdp connector earlier in atomic_enable()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the `drm/bridge: cadence: cdns-mhdp8546-core` component of the Linux kernel. This vulnerability allows for a NULL pointer dereference during error handling within the `atomic_enable()` function. If `cdns_mhdp_link_up()` or `cdns_mhdp_reg_read()` encounter errors, a subsequent attempt to access a mutex in `cdns_mhdp_modeset_retry_fn()` can result in a NULL pointer dereference. This can lead to a system crash, causing a denial of service (DoS).
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Description OSIDB Bzimport 2026-06-24 18:12:47 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/bridge: cadence: cdns-mhdp8546-core: Set the mhdp connector earlier in atomic_enable()

In case if we get errors in cdns_mhdp_link_up() or cdns_mhdp_reg_read()
in atomic_enable, we will go to cdns_mhdp_modeset_retry_fn() and will hit
NULL pointer while trying to access the mutex. We need the connector to
be set before that. Unlike in legacy cases with flag
!DRM_BRIDGE_ATTACH_NO_CONNECTOR, we do not have connector initialised
in bridge_attach(), so add the mhdp->connector_ptr in device structure
to handle both cases with DRM_BRIDGE_ATTACH_NO_CONNECTOR and
!DRM_BRIDGE_ATTACH_NO_CONNECTOR, set it in atomic_enable() earlier to
avoid possible NULL pointer dereference in recovery paths like
modeset_retry_fn() with the DRM_BRIDGE_ATTACH_NO_CONNECTOR flag set.
Comment 1 Mauro Matteo Cascella 2026-06-25 08:50:19 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062401-CVE-2026-53058-d89c@gregkh/T