DLA 2241-1: linux security update
Package : linux
Version : 3.16.84-1
CVE ID : CVE-2015-8839 CVE-2018-14610 CVE-2018-14611 CVE-2018-14612
CVE-2018-14613 CVE-2019-5108 CVE-2019-19319 CVE-2019-19447
CVE-2019-19768 CVE-2019-20636 CVE-2020-0009 CVE-2020-0543
CVE-2020-1749 CVE-2020-2732 CVE-2020-8647 CVE-2020-8648
CVE-2020-8649 CVE-2020-9383 CVE-2020-10690 CVE-2020-10751
CVE-2020-10942 CVE-2020-11494 CVE-2020-11565 CVE-2020-11608
CVE-2020-11609 CVE-2020-11668 CVE-2020-12114 CVE-2020-12464
CVE-2020-12652 CVE-2020-12653 CVE-2020-12654 CVE-2020-12769
CVE-2020-12770 CVE-2020-12826 CVE-2020-13143
Several vulnerabilities have been discovered in the Linux kernel that
may lead to a privilege escalation, denial of service or information
leaks.
CVE-2015-8839
A race condition was found in the ext4 filesystem implementation.
A local user could exploit this to cause a denial of service
(filesystem corruption).
CVE-2018-14610, CVE-2018-14611, CVE-2018-14612, CVE-2018-14613
Wen Xu from SSLab at Gatech reported that crafted Btrfs volumes
could trigger a crash (Oops) and/or out-of-bounds memory access.
An attacker able to mount such a volume could use this to cause a
denial of service or possibly for privilege escalation.
CVE-2019-5108
Mitchell Frank of Cisco discovered that when the IEEE 802.11
(WiFi) stack was used in AP mode with roaming, it would trigger
roaming for a newly associated station before the station was
authenticated. An attacker within range of the AP could use this
to cause a denial of service, either by filling up a switching
table or by redirecting traffic away from other stations.
CVE-2019-19319
Jungyeon discovered that a crafted filesystem can cause the ext4
implementation to deallocate or reallocate journal blocks. A user
permitted to mount filesystems could use this to cause a denial of
service (crash), or possibly for privilege escalation.
CVE-2019-19447
It was discovered that the ext4 filesystem driver did not safely
handle unlinking of an inode that, due to filesystem corruption,
already has a link count of 0. An attacker able to mount
arbitrary ext4 volumes could use this to cause a denial of service
(memory corruption or crash) or possibly for privilege escalation.
CVE-2019-19768
Tristan Madani reported a race condition in the blktrace debug
facility that could result in a use-after-free. A local user able
to trigger removal of block devices could possibly use this to
cause a denial of service (crash) or for privilege escalation.
CVE-2019-20636
The syzbot tool found that the input subsystem did not fully
validate keycode changes, which could result in a heap
out-of-bounds write. A local user permitted to access the device
node for an input or VT device could possibly use this to cause a
denial of service (crash or memory corruption) or for privilege
escalation.
CVE-2020-0009
Jann Horn reported that the Android ashmem driver did not prevent
read-only files from being memory-mapped and then remapped as
read-write. However, Android drivers are not enabled in Debian
kernel configurations.
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-2020-1749
Xiumei Mu reported that some network protocols that can run on top
of IPv6 would bypass the Transformation (XFRM) layer used by
IPsec, IPcomp/IPcomp6, IPIP, and IPv6 Mobility. This could result
in disclosure of information over the network, since it would not
be encrypted or routed according to the system policy.
CVE-2020-2732
Paulo Bonzini discovered that the KVM implementation for Intel
processors did not properly handle instruction emulation for L2
guests when nested virtualization is enabled. This could allow an
L2 guest to cause privilege escalation, denial of service, or
information leaks in the L1 guest.
CVE-2020-8647, CVE-2020-8649
The Hulk Robot tool found a potential MMIO out-of-bounds access in
the vgacon driver. A local user permitted to access a virtual
terminal (/dev/tty1 etc.) on a system using the vgacon driver
could use this to cause a denial of service (crash or memory
corruption) or possibly for privilege escalation.
CVE-2020-8648
The syzbot tool found a race condition in the the virtual terminal
driver, which could result in a use-after-free. A local user
permitted to access a virtual terminal could use this to cause a
denial of service (crash or memory corruption) or possibly for
privilege escalation.
CVE-2020-9383
Jordy Zomer reported an incorrect range check in the floppy driver
which could lead to a static out-of-bounds access. A local user
permitted to access a floppy drive could use this to cause a
denial of service (crash or memory corruption) or possibly for
privilege escalation.
CVE-2020-10690
It was discovered that the PTP hardware clock subsystem did not
properly manage device lifetimes. Removing a PTP hardware clock
from the system while a user process was using it could lead to a
use-after-free. The security impact of this is unclear.
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-2020-10942
It was discovered that the vhost_net driver did not properly
validate the type of sockets set as back-ends. A local user
permitted to access /dev/vhost-net could use this to cause a stack
corruption via crafted system calls, resulting in denial of
service (crash) or possibly privilege escalation.
CVE-2020-11494
It was discovered that the slcan (serial line CAN) network driver
did not fully initialise CAN headers for received packets,
resulting in an information leak from the kernel to user-space or
over the CAN network.
CVE-2020-11565
Entropy Moe reported that the shared memory filesystem (tmpfs) did
not correctly handle an "mpol" mount option specifying an empty
node list, leading to a stack-based out-of-bounds write. If user
namespaces are enabled, a local user could use this to cause a
denial of service (crash) or possibly for privilege escalation.
CVE-2020-11608, CVE-2020-11609, CVE-2020-11668
It was discovered that the ov519, stv06xx, and xirlink_cit media
drivers did not properly validate USB device descriptors. A
physically present user with a specially constructed USB device
could use this to cause a denial-of-service (crash) or possibly
for privilege escalation.
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-2020-12652
Tom Hatskevich reported a bug in the mptfusion storage drivers.
An ioctl handler fetched a parameter from user memory twice,
creating a race condition which could result in incorrect locking
of internal data structures. A local user permitted to access
/dev/mptctl could use this to cause a denial of service (crash or
memory corruption) or for privilege escalation.
CVE-2020-12653
It was discovered that the mwifiex WiFi driver did not
sufficiently validate scan requests, resulting a potential heap
buffer overflow. A local user with CAP_NET_ADMIN capability could
use this to cause a denial of service (crash or memory corruption)
or possibly for privilege escalation.
CVE-2020-12654
It was discovered that the mwifiex WiFi driver did not
sufficiently validate WMM parameters received from an access point
(AP), resulting a potential heap buffer overflow. A malicious AP
could use this to cause a denial of service (crash or memory
corruption) or possibly to execute code on a vulnerable system.
CVE-2020-12769
It was discovered that the spi-dw SPI host driver did not properly
serialise access to its internal state. The security impact of
this is unclear, and this driver is not included in Debian's
binary packages.
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-2020-12826
Adam Zabrocki reported a weakness in the signal subsystem's
permission checks. A parent process can choose an arbitary signal
for a child process to send when it exits, but if the parent has
executed a new program then the default SIGCHLD signal is sent. A
local user permitted to run a program for several days could
bypass this check, execute a setuid program, and then send an
arbitrary signal to it. Depending on the setuid programs
installed, this could have some security impact.
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 Debian 8 "Jessie", these problems have been fixed in version
3.16.84-1.
We recommend that you upgrade your linux packages. Binary packages for
the EABI ARM (armel) architecture are not yet available, and a separate
announcement will be made when they are.
Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS
A linux kernel security update has been released for Debian GNU/Linux 8 LTS to address multiple issues.
