发布于3月6日3月6日 Members Ubuntu: (CVE-2021-47383): linux vulnerability Severity 4 CVSS (AV:L/AC:M/Au:N/C:P/I:P/A:P) Published 05/21/2024 Created 11/21/2024 Added 11/19/2024 Modified 02/11/2025 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) ubuntu-upgrade-linux ubuntu-upgrade-linux-aws ubuntu-upgrade-linux-aws-5-4 ubuntu-upgrade-linux-aws-fips ubuntu-upgrade-linux-aws-hwe ubuntu-upgrade-linux-azure ubuntu-upgrade-linux-azure-4-15 ubuntu-upgrade-linux-azure-5-4 ubuntu-upgrade-linux-azure-fips ubuntu-upgrade-linux-bluefield ubuntu-upgrade-linux-fips ubuntu-upgrade-linux-gcp ubuntu-upgrade-linux-gcp-4-15 ubuntu-upgrade-linux-gcp-5-4 ubuntu-upgrade-linux-gcp-fips ubuntu-upgrade-linux-gkeop ubuntu-upgrade-linux-hwe ubuntu-upgrade-linux-hwe-5-4 ubuntu-upgrade-linux-ibm ubuntu-upgrade-linux-kvm ubuntu-upgrade-linux-oracle ubuntu-upgrade-linux-oracle-5-4 ubuntu-upgrade-linux-raspi ubuntu-upgrade-linux-raspi-5-4 References https://attackerkb.com/topics/cve-2021-47383 CVE - 2021-47383 https://git.kernel.org/linus/3b0c406124719b625b1aba431659f5cdc24a982c 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 https://www.cve.org/CVERecord?id=CVE-2021-47383 View more
