CVE-2022-50222
tty: vt: initialize unicode screen buffer
Published Jun 18, 2025
CVSS 3.1 · 5.5 Medium
EPSS < 1%
KEV · Not listed
Description
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;
}
----------
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 Products
-
CVE record
-
NVD configurations
-
Red Hat packages
No data
-
OpenCVE enrichment
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
Configuration 1 [-]
|
No data.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | — |
Remediation
Tracking
Advisories
| Source | ID | Title |
|---|---|---|
 EUVD |
EUVD-2022-55217 | 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; } ---------- |
Metrics
No CVSS v4.0
Attack Vector Local
Attack Complexity Low
Privileges Required Low
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact High
User Interaction None
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.236% probability within 30 days)
Exploitation none
Automatable no
Technical Impact partial
References
History
Nov 6, 2026 7:30 PM
Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Nov 19, 2025 1:00 PM
Weaknesses updated. Affected versions updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | NVD-CWE-noinfo | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
Jun 19, 2025 3:15 PM
Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Jun 18, 2025 11:15 AM
Description updated. Title updated. Added references
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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; } ---------- | |
| Title | tty: vt: initialize unicode screen buffer | |
| References |
|
|
Subscriptions
Weaknesses
