CVE-2025-38674

Summary

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

Revert "drm/prime: Use dma_buf from GEM object instance"

This reverts commit f83a9b8c7fd0557b0c50784bfdc1bbe9140c9bf8.

The dma_buf field in struct drm_gem_object is not stable over the object instance's lifetime. The field becomes NULL when user space releases the final GEM handle on the buffer object. This resulted in a NULL-pointer deref.

Workarounds in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") and commit f6bfc9afc751 ("drm/framebuffer: Acquire internal references on GEM handles") only solved the problem partially. They especially don't work for buffer objects without a DRM framebuffer associated.

Hence, this revert to going back to using .import_attach->dmabuf.

v3:

  • cc stable

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxf83a9b8c7fd0557b0c50784bfdc1bbe9140c9bf8 < 5f05d83ce689a8930a70dfa73f879604aef8cc03affected
LinuxLinuxf83a9b8c7fd0557b0c50784bfdc1bbe9140c9bf8 < fb4ef4a52b79a22ad382bfe77332642d02aef773affected
LinuxLinux6.15affected
LinuxLinux0 < 6.15unaffected
LinuxLinux6.15.9 <= 6.15.*unaffected
LinuxLinux6.16 <= *unaffected

Weaknesses

References