Debian LTS: DLA-1423-1: linux-4.9 new package
Summary
Linux 4.9 has been packaged for Debian 8 as linux-4.9. This provides
a supported upgrade path for systems that currently use kernel
packages from the "jessie-backports" suite.
There is no need to upgrade systems using Linux 3.16, as that kernel
version will also continue to be supported in the LTS period.
This backport does not include the following binary packages:
hyperv-daemons libcpupower1 libcpupower-dev libusbip-dev
linux-compiler-gcc-4.9-x86 linux-cpupower linux-libc-dev usbip
Older versions of most of those are built from other source packages
in Debian 8.
Several vulnerabilities have been discovered in the Linux kernel that
may lead to a privilege escalation, denial of service or information
leaks.
CVE-2017-5753
Further instances of code that was vulnerable to Spectre variant 1
(bounds-check bypass) have been mitigated.
CVE-2017-18255
It was discovered that the performance events subsystem did not
properly validate the value of the
kernel.perf_cpu_time_max_percent sysctl. Setting a large value
could have an unspecified security impact. However, only a
privileged user can set this sysctl.
CVE-2018-1118
The syzbot software found that the vhost driver did not initialise
message buffers which would later be read by user processes. A
user with access to the /dev/vhost-net device could use this to
read sensitive information from the kernel or other users'
processes.
CVE-2018-1120
Qualys reported that a user able to mount FUSE filesystems can
create a process such that when another process attempting to read
its command line will be blocked for an arbitrarily long time.
This could be used for denial of service, or to aid in exploiting
a race condition in the other program.
CVE-2018-1130
The syzbot software found that the DCCP implementation of
sendmsg() does not check the socket state, potentially leading
to a null pointer dereference. A local user could use this to
cause a denial of service (crash).
CVE-2018-3639
Multiple researchers have discovered that Speculative Store Bypass
(SSB), a feature implemented in many processors, could be used to
read sensitive information from another context. In particular,
code in a software sandbox may be able to read sensitive
information from outside the sandbox. This issue is also known as
Spectre variant 4.
This update allows the issue to be mitigated on some x86
processors by disabling SSB. This requires an update to the
processor's microcode, which is non-free. It may be included in
an update to the system BIOS or UEFI firmware, or in a future
update to the intel-microcode or amd64-microcode packages.
Disabling SSB can reduce performance significantly, so by default
it is only done in tasks that use the seccomp feature.
Applications that require this mitigation should request it
explicitly through the prctl() system call. Users can control
where the mitigation is enabled with the spec_store_bypass_disable
kernel parameter.
CVE-2018-5814
Jakub Jirasek reported race conditions in the USB/IP host driver.
A malicious client could use this to cause a denial of service
(crash or memory corruption), and possibly to execute code, on a
USB/IP server.
CVE-2018-10021
A physically present attacker who unplugs a SAS cable can cause a
denial of service (memory leak and WARN).
CVE-2018-10087, CVE-2018-10124
zhongjiang found that the wait4() and kill() system call
implementations did not check for the invalid pid value of
INT_MIN. If a user passed this value, the behaviour of the code
was formally undefined and might have had a security impact.
CVE-2018-10853
Andy Lutomirski and Mika Penttilä reported that KVM for x86
processors did not perform a necessary privilege check when
emulating certain instructions. This could be used by an
unprivileged user in a guest VM to escalate their privileges
within the guest.
CVE-2018-10876, CVE-2018-10877, CVE-2018-10878, CVE-2018-10879,
CVE-2018-10880, CVE-2018-10881, CVE-2018-10882, CVE-2018-10883
Wen Xu at SSLab, Gatech, reported that crafted ext4 filesystem
images could trigger a crash or memory corruption. A local user
able to mount arbitrary filesystems, or an attacker providing
filesystems to be mounted, could use this for denial of service or
possibly for privilege escalation.
CVE-2018-10940
Dan Carpenter reported that the optical disc driver (cdrom) does
not correctly validate the parameter to the CDROM_MEDIA_CHANGED
ioctl. A user with access to a cdrom device could use this to
cause a denial of service (crash).
CVE-2018-11506
Piotr Gabriel Kosinski and Daniel Shapira reported that the
SCSI optical disc driver (sr) did not allocate a sufficiently
large buffer for sense data. A user with access to a SCSI
optical disc device that can produce more than 64 bytes of
sense data could use this to cause a denial of service (crash
or memory corruption), and possibly for privilege escalation.
CVE-2018-12233
Shankara Pailoor reported that a crafted JFS filesystem image
could trigger a denial of service (memory corruption). This
could possibly also be used for privilege escalation.
CVE-2018-1000204
The syzbot software found that the SCSI generic driver (sg) would
in some circumstances allow reading data from uninitialised
buffers, which could include sensitive information from the kernel
or other tasks. However, only privileged users with the
CAP_SYS_ADMIN or CAP_SYS_RAWIO capability were allowed to do this,
so this has little or no security impact.
For Debian 8 "Jessie", these problems have been fixed in version
4.9.110-1~deb8u1. This update additionally fixes Debian bugs
#860900, #872907, #892057, #896775, #897590, and #898137; and
includes many more bug fixes from stable updates 4.9.89-4.9.110
inclusive.
We recommend that you upgrade your linux-4.9 packages.
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
--
Ben Hutchings - Debian developer, member of kernel, installer and LTS teams
Package :linux-4.9
