CVE-2025-38449
BaseFortify
Publication date: 2025-07-25
Last updated on: 2025-11-19
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | 6.16 |
| linux | linux_kernel | 6.16 |
| linux | linux_kernel | 6.16 |
| linux | linux_kernel | 6.16 |
| linux | linux_kernel | From 5.15.160 (inc) to 5.16 (inc) |
| linux | linux_kernel | From 5.15.160 (inc) to 5.16 (inc) |
| linux | linux_kernel | From 5.15.160 (inc) to 5.16 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-416 | The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability occurs in the Linux kernel's DRM (Direct Rendering Manager) subsystem, specifically related to GEM (Graphics Execution Manager) handles for framebuffers. A GEM handle can be released while the GEM buffer object is still attached to a DRM framebuffer, which leads to the release of the dma-buf backing the buffer object. If the framebuffer is then used in further mode-setting operations, it causes a segmentation fault (crash). This typically happens with drivers that use shadow planes for vmap-ing the dma-buf during a page flip. The fix involves acquiring references on GEM handles for framebuffers to prevent premature release and subsequent crashes.
How can this vulnerability impact me? :
This vulnerability can cause the Linux kernel to crash with a segmentation fault when using certain graphics drivers and operations involving framebuffers. This can lead to system instability, unexpected reboots, or denial of service in environments relying on graphics rendering, potentially disrupting normal operations or user experience.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by monitoring the system logs for kernel warnings or segmentation faults related to dma_buf and GEM framebuffer operations. Specifically, look for kernel log messages similar to the following pattern indicating a dma_buf_vmap warning or segmentation fault: Use the command: sudo dmesg | grep -i 'dma_buf_vmap\|drm_gem_fb_vmap\|segmentation fault' This will help identify if the system has encountered the issue described in the vulnerability.
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation involves updating the Linux kernel to a version where this vulnerability is fixed. The fix involves acquiring references on GEM handles for framebuffers to prevent premature release of dma-buf backing buffer objects. Applying the patch or upgrading to a kernel version that includes the commit "drm/gem-shmem: Use dma_buf from GEM object instance" (commit 1a148af06000) will resolve the issue. Until then, avoid workloads or drivers that trigger the use of shadow planes for vmap-ing dma-buf during page flips if possible.