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
Published: 2026-06-03
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Wed, 03 Jun 2026 17:45:00 +0000

Type Values Removed Values Added
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
Title drm/amd/display: Fix dc_link NULL handling in HPD init
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-06-03T15:49:40.645Z

Reserved: 2026-05-13T15:03:33.107Z

Link: CVE-2026-46245

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-06-03T18:16:24.637

Modified: 2026-06-03T18:16:24.637

Link: CVE-2026-46245

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.