{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72095","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-09T03:40:39.905Z","datePublished":"2026-08-15T05:52:41.470Z","dateUpdated":"2026-08-17T05:40:12.383Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T05:40:12.383Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndma-fence: Make dma_fence_dedup_array() robust against 0-count input\n\ndma_fence_dedup_array() returns 1 when called with num_fences == 0:\nthe for-loop body never executes, j stays at 0, and the final\n`return ++j` yields 1. This contradicts both the kernel-doc (\"Return:\nNumber of unique fences remaining in the array\") and the natural\nexpectation that 0 input gives 0 output.\n\nThe caller __dma_fence_unwrap_merge() bails out via the\n`if (count == 0 || count == 1)` fast path and so is save.\n\nBut amdgpu_userq_wait_*() could reach the dedup call with a zero local\ncount and dereference an uninitialized fence slot in the array.\n\nMake the contract match the documentation by returning 0 early. This\nalso skips an unnecessary sort() call on an empty array."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only via the AMDGPU_USERQ_WAIT DRM ioctl on /dev/dri/renderD*, requiring local access to an AMD GPU render node; it is not reachable from network protocols or remote packet handling.\nAC:L - An attacker with render-node access can reliably trigger the bug by creating a userq, calling AMDGPU_USERQ_WAIT with num_fences>0 and zero syncobj/BO handles so local num_fences stays 0 and dma_fence_dedup_array() incorrectly returns 1.\nPR:L - Exploitation requires only an authenticated DRM client on a render node (DRM_AUTH|DRM_RENDER_ALLOW), which unprivileged users commonly obtain via the render group on workstations, cloud GPU instances, and shared compute nodes.\nUI:N - No victim interaction is required; the attacker drives the vulnerable AMDGPU_USERQ_WAIT ioctl directly after creating their own user queue.\nS:U - Impact remains within the host kernel security domain (local privilege escalation/DoS on the GPU server); it does not cross VM, container, or IOMMU boundaries.\nC:H - When num_fences is 0 the dedup helper returns 1, causing iteration over uninitialized kmalloc slots whose stale contents are then dereferenced via to_amdgpu_userq_fence()/dma_fence_wait(), enabling kernel memory reads and pointer disclosure.\nI:H - The uninitialized fences[0] pointer is passed into dma_fence_enable_sw_signaling() and dma_fence_wait(), which invoke fence ops and locking on attacker-influenced addresses, creating a plausible path to control-flow hijacking via heap grooming.\nA:H - Dereferencing an uninitialized or attacker-influenced dma_fence pointer in kernel context can cause an oops, BUG, or panic, producing a repeatable local denial of service on affected AMDGPU userq systems."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dma-buf/dma-fence-unwrap.c"],"versions":[{"version":"575ec9b0c2f11f40535ea737ed5a64792780d1ef","lessThan":"7aa8f3dba53422465dbe1be8dbb7240304462bb2","status":"affected","versionType":"git"},{"version":"575ec9b0c2f11f40535ea737ed5a64792780d1ef","lessThan":"e2d9a2ea178a5da0b4a6693e8ebca5c7fc4d7051","status":"affected","versionType":"git"},{"version":"575ec9b0c2f11f40535ea737ed5a64792780d1ef","lessThan":"77a9298741f8f9e8b963c977f5582ab21c6d3427","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dma-buf/dma-fence-unwrap.c"],"versions":[{"version":"6.16","status":"affected"},{"version":"0","lessThan":"6.16","status":"unaffected","versionType":"semver"},{"version":"6.18.40","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.5","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/7aa8f3dba53422465dbe1be8dbb7240304462bb2"},{"url":"https://git.kernel.org/stable/c/e2d9a2ea178a5da0b4a6693e8ebca5c7fc4d7051"},{"url":"https://git.kernel.org/stable/c/77a9298741f8f9e8b963c977f5582ab21c6d3427"}],"title":"dma-fence: Make dma_fence_dedup_array() robust against 0-count input","x_generator":{"engine":"bippy-1.2.0"}}}}