CVE-2022-50222

In the Linux kernel, the following vulnerability has been resolved:

tty: vt: initialize unicode screen buffer

syzbot reports kernel infoleak at vcs_read() [1], for buffer can be read immediately after resize operation. Initialize buffer using kzalloc().

#include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <linux/fb.h>

int main(int argc, char *argv[]) { struct fbvarscreeninfo var = { }; const int fbfd = open("/dev/fb0", 3); ioctl(fbfd, FBIOGETVSCREENINFO, &var); var.yres = 0x21; ioctl(fbfd, FBIOPUTVSCREENINFO, &var); return read(open("/dev/vcsu", ORDONLY), &var, sizeof(var)) == -1; }