==========================================================================
Ubuntu Security Notice USN-4948-1
May 11, 2021

linux-oem-5.10 vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-oem-5.10: Linux kernel for OEM systems

Details:

Ryota Shiga discovered that the eBPF implementation in the Linux kernel did
not properly verify that a BPF program only reserved as much memory for a
ring buffer as was allocated. A local attacker could use this to cause a
denial of service (system crash) or execute arbitrary code. (CVE-2021-3489)

Manfred Paul discovered that the eBPF implementation in the Linux kernel
did not properly track bounds on bitwise operations. A local attacker could
use this to cause a denial of service (system crash) or execute arbitrary
code. (CVE-2021-3490)

Billy Jheng Bing-Jhong discovered that the io_uring implementation of the
Linux kernel did not properly enforce the MAX_RW_COUNT limit in some
situations. A local attacker could use this to cause a denial of service
(system crash) or execute arbitrary code. (CVE-2021-3491)

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the
Linux kernel contained a reference counting error. A local attacker could
use this to cause a denial of service (system crash). (CVE-2020-25670)

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the
Linux kernel did not properly deallocate memory in certain error
situations. A local attacker could use this to cause a denial of service
(memory exhaustion). (CVE-2020-25671, CVE-2020-25672)

It was discovered that the Xen paravirtualization backend in the Linux
kernel did not properly deallocate memory in some situations. A local
attacker could use this to cause a denial of service (memory exhaustion).
(CVE-2021-28688)

It was discovered that the io_uring subsystem in the Linux kernel contained
a race condition leading to a deadlock condition. A local attacker could
use this to cause a denial of service. (CVE-2021-28951)

John Stultz discovered that the audio driver for Qualcomm SDM845 systems in
the Linux kernel did not properly validate port ID numbers. A local
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2021-28952)

Zygo Blaxell discovered that the btrfs file system implementation in the
Linux kernel contained a race condition during certain cloning operations.
A local attacker could possibly use this to cause a denial of service
(system crash). (CVE-2021-28964)

Vince Weaver discovered that the perf subsystem in the Linux kernel did
not properly handle certain PEBS records properly for some Intel Haswell
processors. A local attacker could use this cause a denial of service
(system crash). (CVE-2021-28971)

It was discovered that the RPA PCI Hotplug driver implementation in the
Linux kernel did not properly handle device name writes via sysfs, leading
to a buffer overflow. A privileged attacker could use this to cause a
denial of service (system crash) or possibly execute arbitrary code.
(CVE-2021-28972)

It was discovered that the Freescale Gianfar Ethernet driver for the Linux
kernel did not properly handle receive queue overrun when jumbo frames were
enabled in some situations. An attacker could use this to cause a denial of
service (system crash). (CVE-2021-29264)

It was discovered that the vDPA backend virtio driver in the Linux kernel
contained a use-after-free vulnerability. An attacker could use this to
cause a denial of service (system crash) or possibly execute arbitrary
code. (CVE-2021-29266)

It was discovered that the TIPC protocol implementation in the Linux kernel
did not properly validate passed encryption key sizes. A local attacker
could use this to cause a denial of service (system crash).
(CVE-2021-29646)

It was discovered that the Qualcomm IPC router implementation in the Linux
kernel did not properly initialize memory passed to user space. A local
attacker could use this to expose sensitive information (kernel memory).
(CVE-2021-29647)

It was discovered that the BPF user mode driver implementation in the Linux
kernel did not properly deallocate memory in some situations. A local
attacker could use this to cause a denial of service (memory exhaustion).
(CVE-2021-29649)

It was discovered that a race condition existed in the netfilter subsystem
of the Linux kernel when replacing tables. A local attacker could use this
to cause a denial of service (system crash). (CVE-2021-29650)

Felix Wilhelm discovered that the KVM implementation in the Linux kernel
for AMD processors contained race conditions on nested VMCB controls. A
local attacker in a guest vm could possibly use this to gain elevated
privileges. (CVE-2021-29657)

Dan Carpenter discovered that the block device manager (dm) implementation
in the Linux kernel contained a buffer overflow in the ioctl for listing
devices. A privileged local attacker could use this to cause a denial of
service (system crash). (CVE-2021-31916)

马哲宇 discovered that the IEEE 1394 (Firewire) nosy packet sniffer
driver in the Linux kernel did not properly perform reference counting in
some situations, leading to a use-after-free vulnerability. A local
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2021-3483)

Update instructions:

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

Ubuntu 20.04 LTS:
  linux-image-5.10.0-1026-oem     5.10.0-1026.27
  linux-image-oem-20.04b          5.10.0.1026.27

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.

References:
  https://ubuntu.com/security/notices/USN-4948-1
  CVE-2020-25670, CVE-2020-25671, CVE-2020-25672, CVE-2021-28688,
  CVE-2021-28951, CVE-2021-28952, CVE-2021-28964, CVE-2021-28971,
  CVE-2021-28972, CVE-2021-29264, CVE-2021-29266, CVE-2021-29646,
  CVE-2021-29647, CVE-2021-29649, CVE-2021-29650, CVE-2021-29657,
  CVE-2021-31916, CVE-2021-3483, CVE-2021-3489, CVE-2021-3490,
  CVE-2021-3491

Package Information:
  https://launchpad.net/ubuntu/+source/linux-oem-5.10/5.10.0-1026.27