A linux-4.9 security update has been released for Debian GNU/Linux 8 Extended LTS to address several vulnerabilities.

ELA-577-1 linux-4.9 security update

Package linux-4.9
Version 4.9.303-1~deb8u1
Related CVEs CVE-2021-3640 CVE-2021-3752 CVE-2021-4002 CVE-2021-4083 CVE-2021-4155 CVE-2021-4202 CVE-2021-28711 CVE-2021-28712 CVE-2021-28713 CVE-2021-28714 CVE-2021-28715 CVE-2021-29264 CVE-2021-33033 CVE-2021-39685 CVE-2021-39686 CVE-2021-39698 CVE-2021-39714 CVE-2021-43976 CVE-2021-45095 CVE-2022-0001 CVE-2022-0002 CVE-2022-0330 CVE-2022-0435 CVE-2022-0487 CVE-2022-0492 CVE-2022-0617 CVE-2022-24448 CVE-2022-25258 CVE-2022-25375

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

CVE-2021-3640

LinMa of BlockSec Team discovered a race condition in the
Bluetooth SCO implementation that can lead to a use-after-free. A
local user could exploit this to cause a denial of service (memory
corruption or crash) or possibly for privilege escalation.
CVE-2021-3752

Likang Luo of NSFOCUS Security Team discovered a flaw in the
Bluetooth L2CAP implementation that can lead to a user-after-free.
A local user could exploit this to cause a denial of service
(memory corruption or crash) or possibly for privilege escalation.
CVE-2021-4002

It was discovered that hugetlbfs, the virtual filesystem used by
applications to allocate huge pages in RAM, did not flush the
CPU's TLB in one case where it was necessary. In some
circumstances a local user would be able to read and write huge
pages after they are freed and reallocated to a different process.
This could lead to privilege escalation, denial of service or
information leaks.
CVE-2021-4083

Jann Horn reported a race condition in the local (Unix) sockets
garbage collector, that can lead to use-after-free. A local user
could exploit this to cause a denial of service (memory corruption
or crash) or possibly for privilege escalation.
CVE-2021-4155

Kirill Tkhai discovered a data leak in the way the XFS_IOC_ALLOCSP
IOCTL in the XFS filesystem allowed for a size increase of files
with unaligned size. A local attacker can take advantage of this
flaw to leak data on the XFS filesystem.
CVE-2021-4202

Lin Ma discovered a race condition in the NCI (NFC Controller
Interface) driver, which could lead to a use-after-free. A local
user could exploit this to cause a denial of service (memory
corruption or crash) or possibly for privilege escalation.

This protocol is not enabled in Debian's official kernel
configurations.
CVE-2021-28711, CVE-2021-28712, CVE-2021-28713 (XSA-391)

Juergen Gross reported that malicious PV backends can cause a denial
of service to guests being serviced by those backends via high
frequency events, even if those backends are running in a less
privileged environment.
CVE-2021-28714, CVE-2021-28715 (XSA-392)

Juergen Gross discovered that Xen guests can force the Linux
netback driver to hog large amounts of kernel memory, resulting in
denial of service.
CVE-2021-29264

It was discovered that the "gianfar" Ethernet driver used with
some Freescale SoCs did not correctly handle a Rx queue overrun
when jumbo packets were enabled. On systems using this driver and
jumbo packets, an attacker on the network could exploit this to
cause a denial of service (crash).

This driver is not enabled in Debian's official kernel
configurations.
CVE-2021-33033

The syzbot tool found a reference counting bug in the CIPSO
implementation that can lead to a use-after-free.

This protocol is not enabled in Debian's official kernel
configurations.
CVE-2021-39685

Szymon Heidrich discovered a buffer overflow vulnerability in the
USB gadget subsystem, resulting in information disclosure, denial of
service or privilege escalation.
CVE-2021-39686

A race condition was discovered in the Android binder driver, that
could lead to incorrect security checks. On systems where the
binder driver is loaded, a local user could exploit this for
privilege escalation.

This driver is not enabled in Debian's official kernel
configurations.
CVE-2021-39698

Linus Torvalds reported a flaw in the file polling implementation,
which could lead to a use-after-free. A local user could exploit
this for denial of service (memory corruption or crash) or
possibly for privilege escalation.
CVE-2021-39714

A potential reference count overflow was found in the Android Ion
driver. On systems where the Ion driver is loaded, a local user
could exploit this for denial of service (memory corruption or
crash) or possibly for privilege escalation.

This driver is not enabled in Debian's official kernel
configurations.
CVE-2021-43976

Zekun Shen and Brendan Dolan-Gavitt discovered a flaw in the
mwifiex_usb_recv() function of the Marvell WiFi-Ex USB Driver. An
attacker able to connect a crafted USB device can take advantage of
this flaw to cause a denial of service.
CVE-2021-45095

It was discovered that the Phone Network protocol (PhoNet) driver
has a reference count leak in the pep_sock_accept() function.
CVE-2022-0001 (INTEL-SA-00598)

Researchers at VUSec discovered that the Branch History Buffer in
Intel processors can be exploited to create information side-
channels with speculative execution. This issue is similar to
Spectre variant 2, but requires additional mitigations on some
processors.

This can be exploited to obtain sensitive information from a
different security context, such as from user-space to the kernel,
or from a KVM guest to the kernel.
CVE-2022-0002 (INTEL-SA-00598)

This is a similar issue to CVE-2022-0001, but covers exploitation
within a security context, such as from JIT-compiled code in a
sandbox to hosting code in the same process.

This can be partly mitigated by disabling eBPF for unprivileged
users with the sysctl: kernel.unprivileged_bpf_disabled=2. This
update does that by default.
CVE-2022-0330

Sushma Venkatesh Reddy discovered a missing GPU TLB flush in the
i915 driver, resulting in denial of service or privilege escalation.
CVE-2022-0435

Samuel Page and Eric Dumazet reported a stack overflow in the
networking module for the Transparent Inter-Process Communication
(TIPC) protocol, resulting in denial of service or potentially the
execution of arbitrary code.
CVE-2022-0487

A use-after-free was discovered in the MOXART SD/MMC Host Controller
support driver. This flaw does not impact the Debian binary packages
as CONFIG_MMC_MOXART is not set.
CVE-2022-0492

Yiqi Sun and Kevin Wang reported that the cgroup-v1 subsystem does
not properly restrict access to the release-agent feature. A local
user can take advantage of this flaw for privilege escalation and
bypass of namespace isolation.
CVE-2022-0617

butt3rflyh4ck discovered a NULL pointer dereference in the UDF
filesystem. A local user that can mount a specially crafted UDF
image can use this flaw to crash the system.
CVE-2022-24448

Lyu Tao reported a flaw in the NFS implementation in the Linux
kernel when handling requests to open a directory on a regular file,
which could result in a information leak.
CVE-2022-25258

Szymon Heidrich reported the USB Gadget subsystem lacks certain
validation of interface OS descriptor requests, resulting in memory
corruption.
CVE-2022-25375

Szymon Heidrich reported that the RNDIS USB gadget lacks validation
of the size of the RNDIS_MSG_SET command, resulting in information
leak from kernel memory.
For Debian 8 jessie, these problems have been fixed in version 4.9.303-1~deb8u1.

We recommend that you upgrade your linux-4.9 packages.

Further information about Extended LTS security advisories can be found at: https://deb.freexian.com/extended-lts/

  ELA-577-1 linux-4.9 security update