CVE-2026-46245
🔶 mediumSummary
In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix dc_link NULL handling in HPD init amdgpu_dm_hpd_init() may see connectors without a valid dc_link. The code already checks dc_link for the polling decision, but later unconditionally dereferences it when setting up HPD interrupts. Assign dc_link early and skip connectors where it is NULL. Fixes the below: drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_irq.c:940 amdgpu_dm_hpd_init() error: we
Description
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix dc_link NULL handling in HPD init
amdgpu_dm_hpd_init() may see connectors without a valid dc_link.
The code already checks dc_link for the polling decision, but later
unconditionally dereferences it when setting up HPD interrupts.
Assign dc_link early and skip connectors where it is NULL.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_irq.c:940 amdgpu_dm_hpd_init()
error: we previously assumed 'dc_link' could be null (see line 931)
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_irq.c
923 /*
924 * Analog connectors may be hot-plugged unlike other connector
925 * types that don't support HPD. Only poll analog connectors.
926 */
927 use_polling |=
928 amdgpu_dm_connector->dc_link &&
^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The patch adds this NULL check but hopefully it can be removed
929 dc_connector_supports_analog(amdgpu_dm_connector->dc_link->link_id.id);
930
931 dc_link = amdgpu_dm_connector->dc_link;
dc_link assigned here.
932
933 /*
934 * Get a base driver irq reference for hpd ints for the lifetime
935 * of dm. Note that only hpd interrupt types are registered with
936 * base driver; hpd_rx types aren't. IOW, amdgpu_irq_get/put on
937 * hpd_rx isn't available. DM currently controls hpd_rx
938 * explicitly with dc_interrupt_set()
939 */
--> 940 if (dc_link->irq_source_hpd != DC_IRQ_SOURCE_INVALID) {
^^^^^^^^^^^^^^^^^^^^^^^ If it's NULL then we are trouble because we dereference it here.
941 irq_type = dc_link->irq_source_hpd - DC_IRQ_SOURCE_HPD1;
942 /*
943 * TODO: There's a mismatch between mode_info.num_hpd
944 * and what bios reports as the # of connectors with hpd
📊 Relative Risk Intelligence
This CVE is Lower Risk - more severe than 32.6% of all 326,604 vulnerabilities in our database.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H