CVE-2021-47383

Advisory lineage Upstream: 0 Downstream: 78
Modified
Published: 21 May 2024, 15:03
Last modified:11 May 2026, 13:53

Vulnerability Summary

Overall Risk (default)
medium
28/100
CVSS Score
7.1 HIGH
v3.1 (nvd)
EPSS Score
<0.01% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

21 May 2024, 15:03
Published
Vulnerability first disclosed
11 May 2026, 13:53
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.1•HIGH•Score: 7.1CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 1%

Techniques & Countermeasures

  • CWE-125•Out-of-bounds Read

    The product reads data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • linux•linux

    ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 7e71fcedfda6f7de18f850a6b36e78d78b04476f | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 70aed03b1d5a5df974f456cdc8eedb213c94bb8b | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 067c694d06040db6f0c65281bb358452ca6d85b9 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 8a6a240f52e14356386030d8958ae8b1761d2325 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 883f7897a25e3ce14a7f274ca4c73f49ac84002a | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < d570c48dd37dbe8fc6875d4461d01a9554ae2560 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 699d926585daa6ec44be556cdc1ab89e5d54557b | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 3b0c406124719b625b1aba431659f5cdc24a982c | 2.6.12

  • linux•linux_kernel

    < 4.4.286 | ≥ 4.5, < 4.9.285 | ≥ 4.10, < 4.14.249 | ≥ 4.15, < 4.19.209 | ≥ 4.20, < 5.4.151 | ≥ 5.5, < 5.10.71 | ≥ 5.11, < 5.14.10

References (8)