Linux Kernel up to 6.17.2 dc_stream_set_cursor_attributes null pointer dereference

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.17.2. The affected element is the function dc_stream_set_cursor_attributes. Such manipulation leads to null pointer dereference. This vulnerability is uniquely identified as CVE-2025-40148. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.17.2. It has been rated as critical. Affected by this issue is the function dc_stream_set_cursor_attributes. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add NULL pointer checks in dc_stream cursor attribute functions The function dc_stream_set_cursor_attributes() currently dereferences the `stream` pointer and nested members `stream->ctx->dc->current_state` without checking for NULL. All callers of these functions, such as in `dcn30_apply_idle_power_optimizations()` and `amdgpu_dm_plane_handle_cursor_update()`, already perform NULL checks before calling these functions. Fixes below: drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:336 dc_stream_program_cursor_attributes() error: we previously assumed 'stream' could be null (see line 334) drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c 327 bool dc_stream_program_cursor_attributes( 328 struct dc_stream_state *stream, 329 const struct dc_cursor_attributes *attributes) 330 { 331 struct dc *dc; 332 bool reset_idle_optimizations = false; 333 334 dc = stream ? stream->ctx->dc : NULL; ^^^^^^ The old code assumed stream could be NULL. 335 --> 336 if (dc_stream_set_cursor_attributes(stream, attributes)) { ^^^^^^ The refactor added an unchecked dereference. drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c 313 bool dc_stream_set_cursor_attributes( 314 struct dc_stream_state *stream, 315 const struct dc_cursor_attributes *attributes) 316 { 317 bool result = false; 318 319 if (dc_stream_check_cursor_attributes(stream, stream->ctx->dc->current_state, attributes)) { ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Here. This function used to check for if stream as NULL and return false at the start. Probably we should add that back.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2025-40148 since 04/16/2025. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 298897 (Ubuntu 25.10 : Linux kernel vulnerabilities (USN-8029-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.17.3 or 6.18-rc1 eliminates this vulnerability. Applying the patch 01e793e7d4d402c473f1a61ca5824f086693be65/bf4e4b97d0fdc66f04fc19d807e24dd8421b8f11 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (298897) and CERT Bund (WID-SEC-2025-2579). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.17.0
• 6.17.1
• 6.17.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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