CVE-2026-43318

/* * PoC Concept for CVE-2026-43318 * This code demonstrates the logic to trigger the race condition. * Requires a system with 2 AMD GPUs (GPU0, GPU1) and no P2P support. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <drm/amdgpu_drm.h> // Mock function to simulate triggering the scenario void trigger_vulnerability() { // 1. Export linear buffer from GPU0 printf("[+] Step 1: Exporting linear buffer from GPU0...\n"); // int prime_fd = export_dmabuf(gpu0_device, bo_handle); // 2. Import buffer to GPU1 printf("[+] Step 2: Importing buffer using GPU1...\n"); // import_dmabuf(gpu1_device, prime_fd); // 3. Submit frame rendering and blit job to GPU0 printf("[+] Step 3: Submitting blit job to GPU0...\n"); // submit_blit(gpu0_device, bo_handle); // Note: The job is queued but we need to race the move notification. // 4. Trigger move notification while blit is running // This simulates the Xorg copy operation or explicit move printf("[+] Step 4: Triggering buffer move (invalidation) for GPU1...\n"); // amdgpu_dma_buf_move_notify(prime_fd); // This calls amdgpu_vm_handle_moved which updates PT immediately. // 5. Race condition occurs -> Page Fault printf("[!] Step 5: If race won, GPU0 blit job page faults.\n"); } int main() { // Check root privileges if (getuid() != 0) { printf("Privileges required.\n"); return 1; } trigger_vulnerability(); return 0; }

{"cve": {"id": "CVE-2026-43318", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-08T14:16:40.363", "lastModified": "2026-05-15T18:22:33.780", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu: fix sync handling in amdgpu_dma_buf_move_notify\n\nInvalidating a dmabuf will impact other users of the shared BO.\nIn the scenario where process A moves the BO, it needs to inform\nprocess B about the move and process B will need to update its\npage table.\n\nThe commit fixes a synchronisation bug caused by the use of the\nticket: it made amdgpu_vm_handle_moved behave as if updating\nthe page table immediately was correct but in this case it's not.\n\nAn example is the following scenario, with 2 GPUs and glxgears\nrunning on GPU0 and Xorg running on GPU1, on a system where P2P\nPCI isn't supported:\n\nglxgears:\n export linear buffer from GPU0 and import using GPU1\n submit frame rendering to GPU0\n submit tiled->linear blit\nXorg:\n copy of linear buffer\n\nThe sequence of jobs would be:\n drm_sched_job_run # GPU0, frame rendering\n drm_sched_job_queue # GPU0, blit\n drm_sched_job_done # GPU0, frame rendering\n drm_sched_job_run # GPU0, blit\n move linear buffer for GPU1 access #\n amdgpu_dma_buf_move_notify -> update pt # GPU0\n\nIt this point the blit job on GPU0 is still running and would\nlikely produce a page fault."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.12.75", "matchCriteriaId": "3E952027-3F78-4493-B648-5D99B5D396A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.16", "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/3307459eb3583115264421e859858d1f90f3694a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/82a7ea35a1526bef8ae170c33ff80e5db7728961", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/89a9389ad70d3c69538e59d87df67d407aef4c26", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/b18fc0ab837381c1a6ef28386602cd888f2d9edf", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}