USN-5115-1: Linux kernel (OEM) vulnerabilities

20 October 2021

Several security issues were fixed in the Linux kernel.

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Releases

Packages

Details

It was discovered that a race condition existed in the Atheros Ath9k WiFi
driver in the Linux kernel. An attacker could possibly use this to expose
sensitive information (WiFi network traffic). (CVE-2020-3702)

Ofek Kirzner, Adam Morrison, Benedict Schlueter, and Piotr Krysiuk
discovered that the BPF verifier in the Linux kernel missed possible
mispredicted branches due to type confusion, allowing a side-channel
attack. An attacker could use this to expose sensitive information.
(CVE-2021-33624)

Benedict Schlueter discovered that the BPF subsystem in the Linux kernel
did not properly protect against Speculative Store Bypass (SSB) side-
channel attacks in some situations. A local attacker could possibly use
this to expose sensitive information. (CVE-2021-34556)

Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not
properly protect against Speculative Store Bypass (SSB) side-channel
attacks in some situations. A local attacker could possibly use this to
expose sensitive information. (CVE-2021-35477)

It was discovered that the tracing subsystem in the Linux kernel did not
properly keep track of per-cpu ring buffer state. A privileged attacker
could use this to cause a denial of service. (CVE-2021-3679)

It was discovered that the Option USB High Speed Mobile device driver in
the Linux kernel did not properly handle error conditions. A physically
proximate attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-37159)

Alois Wohlschlager discovered that the overlay file system in the Linux
kernel did not restrict private clones in some situations. An attacker
could use this to expose sensitive information. (CVE-2021-3732)

It was discovered that the btrfs file system in the Linux kernel did not
properly handle removing a non-existent device id. An attacker with
CAP_SYS_ADMIN could use this to cause a denial of service. (CVE-2021-3739)

It was discovered that the Qualcomm IPC Router protocol implementation in
the Linux kernel did not properly validate metadata in some situations. A
local attacker could use this to cause a denial of service (system crash)
or expose sensitive information. (CVE-2021-3743)

It was discovered that the virtual terminal (vt) device implementation in
the Linux kernel contained a race condition in its ioctl handling that led
to an out-of-bounds read vulnerability. A local attacker could possibly use
this to expose sensitive information. (CVE-2021-3753)

It was discovered that the Linux kernel did not properly account for the
memory usage of certain IPC objects. A local attacker could use this to
cause a denial of service (memory exhaustion). (CVE-2021-3759)

It was discovered that the BPF subsystem in the Linux kernel contained an
integer overflow in its hash table implementation. A local attacker could
use this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2021-38166)

It was discovered that the MAX-3421 host USB device driver in the Linux
kernel did not properly handle device removal events. A physically
proximate attacker could use this to cause a denial of service (system
crash). (CVE-2021-38204)

It was discovered that the Xilinx 10/100 Ethernet Lite device driver in the
Linux kernel could report pointer addresses in some situations. An attacker
could use this information to ease the exploitation of another
vulnerability. (CVE-2021-38205)

It was discovered that the ext4 file system in the Linux kernel contained a
race condition when writing xattrs to an inode. A local attacker could use
this to cause a denial of service or possibly gain administrative
privileges. (CVE-2021-40490)

It was discovered that the 6pack network protocol driver in the Linux
kernel did not properly perform validation checks. A privileged attacker
could use this to cause a denial of service (system crash) or execute
arbitrary code. (CVE-2021-42008)

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Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

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Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 20.04

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.