[SECURITY] [DSA 4699-1] linux security update

Debian Security Advisory DSA-4699-1 [email protected]
https://www.debian.org/security/ Ben Hutchings
June 09, 2020 https://www.debian.org/security/faq

Package : linux
CVE ID : CVE-2019-3016 CVE-2019-19462 CVE-2020-0543 CVE-2020-10711
CVE-2020-10732 CVE-2020-10751 CVE-2020-10757 CVE-2020-12114
CVE-2020-12464 CVE-2020-12768 CVE-2020-12770 CVE-2020-13143
Debian Bug : 960271

Several vulnerabilities have been discovered in the Linux kernel that
may lead to a privilege escalation, denial of service or information
leaks.

CVE-2019-3016

It was discovered that the KVM implementation for x86 did not
always perform TLB flushes when needed, if the paravirtualised
TLB flush feature was enabled.  This could lead to disclosure of
sensitive information within a guest VM.

CVE-2019-19462

The syzkaller tool found a missing error check in the 'relay'
library used to implement various files under debugfs.  A local
user permitted to access debugfs could use this to cause a denial
of service (crash) or possibly for privilege escalation.

CVE-2020-0543

Researchers at VU Amsterdam discovered that on some Intel CPUs
supporting the RDRAND and RDSEED instructions, part of a random
value generated by these instructions may be used in a later
speculative execution on any core of the same physical CPU.
Depending on how these instructions are used by applications, a
local user or VM guest could use this to obtain sensitive
information such as cryptographic keys from other users or VMs.

This vulnerability can be mitigated by a microcode update, either
as part of system firmware (BIOS) or through the intel-microcode
package in Debian's non-free archive section.  This kernel update
only provides reporting of the vulnerability and the option to
disable the mitigation if it is not needed.

CVE-2020-10711

Matthew Sheets reported NULL pointer dereference issues in the
SELinux subsystem while receiving CIPSO packet with null category. A
remote attacker can take advantage of this flaw to cause a denial of
service (crash). Note that this issue does not affect the binary
packages distributed in Debian as CONFIG_NETLABEL is not enabled.

CVE-2020-10732

An information leak of kernel private memory to userspace was found
in the kernel's implementation of core dumping userspace processes.

CVE-2020-10751

Dmitry Vyukov reported that the SELinux subsystem did not properly
handle validating multiple messages, which could allow a privileged
attacker to bypass SELinux netlink restrictions.

CVE-2020-10757

Fan Yang reported a flaw in the way mremap handled DAX hugepages,
allowing a local user to escalate their privileges.

CVE-2020-12114

Piotr Krysiuk discovered a race condition between the umount and
pivot_root operations in the filesystem core (vfs).  A local user
with the CAP_SYS_ADMIN capability in any user namespace could use
this to cause a denial of service (crash).

CVE-2020-12464

Kyungtae Kim reported a race condition in the USB core that can
result in a use-after-free.  It is not clear how this can be
exploited, but it could result in a denial of service (crash or
memory corruption) or privilege escalation.

CVE-2020-12768

A bug was discovered in the KVM implementation for AMD processors,
which could result in a memory leak.  The security impact of this
is unclear.

CVE-2020-12770

It was discovered that the sg (SCSI generic) driver did not
correctly release internal resources in a particular error case.
A local user permitted to access an sg device could possibly use
this to cause a denial of service (resource exhaustion).

CVE-2020-13143

Kyungtae Kim reported a potential heap out-of-bounds write in
the USB gadget subsystem.  A local user permitted to write to
the gadget configuration filesystem could use this to cause a
denial of service (crash or memory corruption) or potentially
for privilege escalation.

For the stable distribution (buster), these problems have been fixed
in version 4.19.118-2+deb10u1. This version also fixes some related
bugs that do not have their own CVE IDs, and a regression in the
<linux/swab.h> UAPI header introduced in the previous point release
(bug #960271).

We recommend that you upgrade your linux packages.

For the detailed security status of linux please refer to its security
tracker page at:
https://security-tracker.debian.org/tracker/linux

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/

Mailing list: [email protected]