Medium [CVE-2026-68275] Linux kernel: drm/amdgpu null pointer dereference via unmapped buffer object
This medium-severity Red Hat Linux advisory covers CVE-2026-68275.
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Summary
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: check amdgpu_vm_bo_find() result in GET_MAPPING_INFO The AMDGPU_GEM_OP_GET_MAPPING_INFO path of amdgpu_gem_op_ioctl() looks up the bo_va for the buffer object in the caller's VM via amdgpu_vm_bo_find(), but uses the returned pointer without checking it. amdgpu_vm_bo_find() returns NULL when the BO has no bo_va in that VM, which is the normal case for a BO that has never been mapped.
The result is fed straight into amdgpu_vm_bo_va_for_each_valid_mapping(), which expands to list_for_each_entry(mapping, &(bo_va)->valids, list) and dereferences bo_va, causing a NULL pointer dereference. This is reachable by any process able to issue the ioctl (render group) simply by requesting mapping info for an unmapped BO.
Return -ENOENT when no bo_va is found, jumping to out_exec so the drm_exec context and GEM object reference are released. (cherry picked from commit 528b19377affc1cc7362a70a254c1dda793595f9) A local attacker, with the ability to issue ioctl commands to the render group, could trigger a null pointer dereference by requesting mapping information for an unmapped buffer object.
This could lead to a system crash, resulting in a denial of service. Red Hat severity: Moderate — CVSS 4.7 (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H).
Weakness: CWE-476.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source
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