CVE-2026-31777

#include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <stdio.h> #include <stdlib.h> // This is a conceptual Proof of Concept for CVE-2026-31777. // It attempts to interact with the ALSA device to trigger the bug. #define DEVICE_PATH "/dev/snd/controlC0" // Common ALSA device path int main() { int fd; // Open the ALSA control device fd = open(DEVICE_PATH, O_RDWR); if (fd < 0) { perror("Failed to open device"); return EXIT_FAILURE; } printf("Device opened successfully. Triggering vulnerability...\n"); // In a real exploit scenario, specific IOCTLs or sequence of operations // would be crafted to force daio_device_index() to return an error code // that the driver does not handle, leading to a crash. // Since specific IOCTL numbers are hardware/driver specific, // this represents the interaction point. // Example placeholder for triggering logic: // ioctl(fd, SNDRV_CTL_IOCTL_ELEM_..., ...); close(fd); printf("Interaction completed. Check kernel logs for instability.\n"); return 0; }

{"cve": {"id": "CVE-2026-31777", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-01T15:16:41.087", "lastModified": "2026-05-07T02:27:02.030", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: ctxfi: Check the error for index mapping\n\nThe ctxfi driver blindly assumed a proper value returned from\ndaio_device_index(), but it's not always true. Add a proper error\ncheck to deal with the error from the function."}], "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": "2.6.31", "versionEndExcluding": "6.19.12", "matchCriteriaId": "B5A73A70-0997-4187-B1E3-6AF168E6E50F"}, {"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"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/277c6960d4ddb94d16198afd70c92c3d4593d131", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d4d3b8cbb70a2de247cbfe99bdb232aef9ed59bc", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}