CVE-2021-47383 Affecting kernel-uki-virt package, versions <0:5.14.0-427.42.1.el9_4
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Test your applications- Snyk ID SNYK-ALMALINUX9-KERNELUKIVIRT-8333953
- published 4 Nov 2024
- disclosed 30 Oct 2024
How to fix?
Upgrade AlmaLinux:9 kernel-uki-virt to version 0:5.14.0-427.42.1.el9_4 or higher.
This issue was patched in ALSA-2024:8617.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-uki-virt package and not the kernel-uki-virt package as distributed by AlmaLinux.
See How to fix? for AlmaLinux:9 relevant fixed versions and status.
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.
References
- https://errata.almalinux.org/8/ALSA-2024-7000.html
- https://errata.almalinux.org/8/ALSA-2024-7001.html
- https://errata.almalinux.org/9/ALSA-2024-8617.html
- https://access.redhat.com/security/cve/CVE-2021-47383
- https://access.redhat.com/errata/RHSA-2024:7000
- https://access.redhat.com/errata/RHSA-2024:7001
- https://access.redhat.com/errata/RHSA-2024:8617
- https://git.kernel.org/stable/c/067c694d06040db6f0c65281bb358452ca6d85b9
- https://git.kernel.org/stable/c/3b0c406124719b625b1aba431659f5cdc24a982c
- https://git.kernel.org/stable/c/699d926585daa6ec44be556cdc1ab89e5d54557b
- https://git.kernel.org/stable/c/70aed03b1d5a5df974f456cdc8eedb213c94bb8b
- https://git.kernel.org/stable/c/7e71fcedfda6f7de18f850a6b36e78d78b04476f
- https://git.kernel.org/stable/c/883f7897a25e3ce14a7f274ca4c73f49ac84002a
- https://git.kernel.org/stable/c/8a6a240f52e14356386030d8958ae8b1761d2325
- https://git.kernel.org/stable/c/d570c48dd37dbe8fc6875d4461d01a9554ae2560