In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Fix out-of-bounds stream encoder index v3

eng_id can be negative and that stream_enc_regs[]
can be indexed out of bounds.

eng_id is used directly as an index into stream_enc_regs[], which has
only 5 entries. When eng_id is 5 (ENGINE_ID_DIGF) or negative, this can
access memory past the end of the array.

Add a bounds check using ARRAY_SIZE() before using eng_id as an index.
The unsigned cast also rejects negative values.

This avoids out-of-bounds access.

Fixes the below smatch error:
dcn*_resource.c: stream_encoder_create() may index
stream_enc_regs[eng_id] out of bounds (size 5).

drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn351/dcn351_resource.c
1246 static struct stream_encoder *dcn35_stream_encoder_create(
1247 enum engine_id eng_id,
1248 struct dc_context *ctx)
1249 {

...

1255
1256 /* Mapping of VPG, AFMT, DME register blocks to DIO block instance */
1257 if (eng_id <= ENGINE_ID_DIGF) {

ENGINE_ID_DIGF is 5. should <= be <?

Unrelated but, ugh, why is Smatch saying that "eng_id" can be negative?
end_id is type signed long, but there are checks in the caller which prevent it from being negative.

1258 vpg_inst = eng_id;
1259 afmt_inst = eng_id;
1260 } else
1261 return NULL;
1262

...

1281
1282 dcn35_dio_stream_encoder_construct(enc1, ctx, ctx->dc_bios,
1283 eng_id, vpg, afmt,
--> 1284 &stream_enc_regs[eng_id],
^^^^^^^^^^^^^^^^^^^^^^^ This stream_enc_regs[] array has 5 elements so we are one element beyond the end of the array.

...

1287 return &enc1->base;
1288 }

v2: use explicit bounds check as suggested by Roman/Dan; avoid unsigned int cast

v3: The compiler already knows how to compare the two values, so the
cast (int) is not needed. (Roman)

Project Subscriptions

Vendors Products
Linux Kernel Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 03 Jun 2026 20:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-129
CWE-20

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 out-of-bounds stream encoder index v3 eng_id can be negative and that stream_enc_regs[] can be indexed out of bounds. eng_id is used directly as an index into stream_enc_regs[], which has only 5 entries. When eng_id is 5 (ENGINE_ID_DIGF) or negative, this can access memory past the end of the array. Add a bounds check using ARRAY_SIZE() before using eng_id as an index. The unsigned cast also rejects negative values. This avoids out-of-bounds access. Fixes the below smatch error: dcn*_resource.c: stream_encoder_create() may index stream_enc_regs[eng_id] out of bounds (size 5). drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn351/dcn351_resource.c 1246 static struct stream_encoder *dcn35_stream_encoder_create( 1247 enum engine_id eng_id, 1248 struct dc_context *ctx) 1249 { ... 1255 1256 /* Mapping of VPG, AFMT, DME register blocks to DIO block instance */ 1257 if (eng_id <= ENGINE_ID_DIGF) { ENGINE_ID_DIGF is 5. should <= be <? Unrelated but, ugh, why is Smatch saying that "eng_id" can be negative? end_id is type signed long, but there are checks in the caller which prevent it from being negative. 1258 vpg_inst = eng_id; 1259 afmt_inst = eng_id; 1260 } else 1261 return NULL; 1262 ... 1281 1282 dcn35_dio_stream_encoder_construct(enc1, ctx, ctx->dc_bios, 1283 eng_id, vpg, afmt, --> 1284 &stream_enc_regs[eng_id], ^^^^^^^^^^^^^^^^^^^^^^^ This stream_enc_regs[] array has 5 elements so we are one element beyond the end of the array. ... 1287 return &enc1->base; 1288 } v2: use explicit bounds check as suggested by Roman/Dan; avoid unsigned int cast v3: The compiler already knows how to compare the two values, so the cast (int) is not needed. (Roman)
Title drm/amd/display: Fix out-of-bounds stream encoder index v3
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-06-03T15:50:02.572Z

Reserved: 2026-05-13T15:03:33.108Z

Link: CVE-2026-46263

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-06-03T18:16:27.743

Modified: 2026-06-03T18:16:27.743

Link: CVE-2026-46263

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-03T20:15:26Z

Weaknesses