发布于3月6日3月6日 Members Red Hat: CVE-2021-47383: kernel: tty: Fix out-of-bound vmalloc access in imageblit (Multiple Advisories) Severity 6 CVSS (AV:L/AC:L/Au:S/C:P/I:P/A:C) Published 05/21/2024 Created 09/14/2024 Added 09/13/2024 Modified 12/12/2024 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) redhat-upgrade-kernel redhat-upgrade-kernel-rt References CVE-2021-47383 RHSA-2024:5364 RHSA-2024:5365 RHSA-2024:7000 RHSA-2024:7001 RHSA-2024:8617
