USN-5137-2: Linux kernel vulnerabilities

11 November 2021

Several security issues were fixed in the Linux kernel.

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Details

It was discovered that the f2fs file system in the Linux kernel did not
properly validate metadata in some situations. An attacker could use this
to construct a malicious f2fs image that, when mounted and operated on,
could cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2019-19449)

It was discovered that the Infiniband RDMA userspace connection manager
implementation in the Linux kernel contained a race condition leading to a
use-after-free vulnerability. A local attacker could use this to cause a
denial of service (system crash) or possible execute arbitrary code.
(CVE-2020-36385)

Wolfgang Frisch discovered that the ext4 file system implementation in the
Linux kernel contained an integer overflow when handling metadata inode
extents. An attacker could use this to construct a malicious ext4 file
system image that, when mounted, could cause a denial of service (system
crash). (CVE-2021-3428)

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 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)

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Update instructions

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

Ubuntu 20.04
Ubuntu 18.04

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.

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