CVE-2021-47383

7.1 HIGH
Published: May 21, 2024 Modified: December 10, 2025

Description

In the Linux kernel, the following vulnerability has been resolved: tty: Fix out-of-bound vmalloc access in imageblit This issue happens when a userspace program does an ioctl FBIOPUT_VSCREENINFO passing the fb_var_screeninfo struct containing only the fields xres, yres, and bits_per_pixel with values. If this struct is the same as the previous ioctl, the vc_resize() detects it and doesn't call the resize_screen(), leaving the fb_var_screeninfo incomplete. And this leads to the updatescrollmode() calculates a wrong value to fbcon_display->vrows, which makes the real_y() return a wrong value of y, and that value, eventually, causes the imageblit to access an out-of-bound address value. To solve this issue I made the resize_screen() be called even if the screen does not need any resizing, so it will "fix and fill" the fb_var_screeninfo independently.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://git.kernel.org/stable/c/067c694d06040db6f0c65281bb358452ca6d85b9
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/3b0c406124719b625b1aba431659f5cdc24a982c
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/699d926585daa6ec44be556cdc1ab89e5d54557b
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/70aed03b1d5a5df974f456cdc8eedb213c94bb8b
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/7e71fcedfda6f7de18f850a6b36e78d78b04476f
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/883f7897a25e3ce14a7f274ca4c73f49ac84002a
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/8a6a240f52e14356386030d8958ae8b1761d2325
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/d570c48dd37dbe8fc6875d4461d01a9554ae2560
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/067c694d06040db6f0c65281bb358452ca6d85b9
Source: af854a3a-2127-422b-91ae-364da2661108
Patch
https://git.kernel.org/stable/c/3b0c406124719b625b1aba431659f5cdc24a982c
Source: af854a3a-2127-422b-91ae-364da2661108
Patch
https://git.kernel.org/stable/c/699d926585daa6ec44be556cdc1ab89e5d54557b
Source: af854a3a-2127-422b-91ae-364da2661108
Patch
https://git.kernel.org/stable/c/70aed03b1d5a5df974f456cdc8eedb213c94bb8b
Source: af854a3a-2127-422b-91ae-364da2661108
Patch
https://git.kernel.org/stable/c/7e71fcedfda6f7de18f850a6b36e78d78b04476f
Source: af854a3a-2127-422b-91ae-364da2661108
Patch
https://git.kernel.org/stable/c/883f7897a25e3ce14a7f274ca4c73f49ac84002a
Source: af854a3a-2127-422b-91ae-364da2661108
Patch
https://git.kernel.org/stable/c/8a6a240f52e14356386030d8958ae8b1761d2325
Source: af854a3a-2127-422b-91ae-364da2661108
Patch
https://git.kernel.org/stable/c/d570c48dd37dbe8fc6875d4461d01a9554ae2560
Source: af854a3a-2127-422b-91ae-364da2661108
Patch

16 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.1 / 10.0
EPSS (Exploit Probability)
0.0%
0th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

linux