- Debian GNU/Linux 11’s new Linux Kernel security update addressed 9 vulnerabilities that can cause a privilege escalation, leaking information, and denial of service.
- During his talk at the DebConf 22 conference, Debian developer Steve McIntyre stated that Debian might start including non-free firmware.
- The Debian project urged users to update their Debian GNU/Linux 11 “Bullseye” installation to Linux kernel 5.10.127-2 as soon as possible.
A new Linux Kernel security update for Debian GNU/Linux 11 “Bullseye” stable has been released. The update fixes 9 vulnerabilities that can cause a privilege escalation, leaking information, or denial of service. The security update was released approximately 1.5 months after the previous one it addresses nine security vulnerabilities in the Linux Kernel 5.10 LTS, the default kernel for the latest Debian release.
Information leaks and denial of service
The project advised users to update their Debian GNU/Linux 11 “Bullseye” versions to Linux kernel 5.10.127-2 to be safe. Some of the vulnerabilities addressed with this patch are:
CVE-2021-33655: When sending malicious data to kernel by ioctl cmd FBIOPUT_VSCREENINFO, the kernel will write memory out of bounds.
CVE-2022-2318: There are use-after-free vulnerabilities caused by timer handler in net/rose/rose_timer.c of Linux that allow attackers to crash the Linux kernel without any privileges.
CVE-2022-33743: Network backend may cause Linux netfront to use freed SKBs While adding logic to support XDP (eXpress Data Path), a code label was moved in a way allowing for SKBs having references (pointers) retained for further processing to nevertheless be freed.
CVE-2022-33744: Arm guests can cause Dom0 DoS via PV devices When mapping pages of guests on Arm, dom0 is using an rbtree to keep track of the foreign mappings. Updating of that rbtree is not always done completely with the related lock held, resulting in a small race window, which can be used by unprivileged guests via PV devices to cause inconsistencies of the rbtree. These inconsistencies can lead to Denial of Service (DoS) of dom0, e.g. by causing crashes or the inability to perform further mappings of other guests’ memory pages.
CVE-2022-34918: An issue was discovered in the Linux kernel through 5.18.9. A type confusion bug in nft_set_elem_init (leading to a buffer overflow) could be used by a local attacker to escalate privileges, a different vulnerability than CVE-2022-32250. The attacker can obtain root access but must start with an unprivileged user namespace to obtain CAP_NET_ADMIN access.
To update their Debian GNU/Linux 11 installations, users can use a graphical package manager, or use the following commands:
sudo apt update
sudo apt full-upgradeNon-free firmware
A former Debian project leader and a Debian developer since 1996, Steve McIntyre is discussing adding non-free firmware to the distro, which allows the latest devices and configurations to work smoothly. During his talk at the DebConf 22 conference, he shared his opinion on “Fixing the firmware mess” with the audience.
Although it contradicts the project’s policy to include free software, we may see Debian releases with non-free firmware in official releases. There are currently unofficial Debian images that include non-free firmware. When Steve asked for attendees to share their opinion, the majority of them voted in favor of including non-free firmware in images.