CVE-2022-50222

Summary

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 fb_var_screeninfo var = { }; const int fb_fd = open("/dev/fb0", 3); ioctl(fb_fd, FBIOGET_VSCREENINFO, &var); var.yres = 0x21; ioctl(fb_fd, FBIOPUT_VSCREENINFO, &var); return read(open("/dev/vcsu", O_RDONLY), &var, sizeof(var)) == -1; }

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxd8ae7242718738ee1bf9bfdd632d2a4b150fdd26 < e02fa87e572bb7d90dcdbce9c0f519f1eb992e96affected
LinuxLinuxd8ae7242718738ee1bf9bfdd632d2a4b150fdd26 < cc9e874dace0c89ae535230c7da19b764746811eaffected
LinuxLinuxd8ae7242718738ee1bf9bfdd632d2a4b150fdd26 < 5c6c65681f39bf71bc72ed589dec3b8b20e75cacaffected
LinuxLinuxd8ae7242718738ee1bf9bfdd632d2a4b150fdd26 < 446f123aa6021e5f75a20789f05ff3f7ae51a42faffected
LinuxLinuxd8ae7242718738ee1bf9bfdd632d2a4b150fdd26 < 777a462e1ae50a01fc4a871efa8e34d596a1e17daffected
LinuxLinuxd8ae7242718738ee1bf9bfdd632d2a4b150fdd26 < e0ef23e9b0ad18b9fd3741b0f1ad2282e4a18defaffected
LinuxLinuxd8ae7242718738ee1bf9bfdd632d2a4b150fdd26 < af77c56aa35325daa2bc2bed5c2ebf169be61b86affected
LinuxLinux4.19affected
LinuxLinux0 < 4.19unaffected
LinuxLinux4.19.256 <= 4.19.*unaffected
LinuxLinux5.4.211 <= 5.4.*unaffected
LinuxLinux5.10.137 <= 5.10.*unaffected
LinuxLinux5.15.61 <= 5.15.*unaffected
LinuxLinux5.18.18 <= 5.18.*unaffected
LinuxLinux5.19.2 <= 5.19.*unaffected
LinuxLinux6.0 <= *unaffected

Weaknesses

References