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Oracle Linux: CVE-2021-47383: ELSA-2024-7000: kernel security update (IMPORTANT) (Multiple Advisories)

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Oracle Linux: CVE-2021-47383: ELSA-2024-7000:kernel security update (IMPORTANT) (Multiple Advisories)

Severity
6
CVSS
(AV:L/AC:L/Au:S/C:P/I:P/A:C)
Published
05/21/2024
Created
10/18/2024
Added
10/16/2024
Modified
01/07/2025

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.

Solution(s)

  • oracle-linux-upgrade-kernel

References

  • https://attackerkb.com/topics/cve-2021-47383
  • CVE - 2021-47383
  • ELSA-2024-7000
  • ELSA-2024-8617
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