Race condition in the netlink_dump function in net/netlink/af_netlink.c in the Linux kernel before 4.6.3 allows local users to cause a deni…

published 2016-12-28 9 y ago modified 2026-06-17 4 mo ago also EUVD-2016-10607

cvss: 7.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits: 0; none known

Race condition in the netlink_dump function in net/netlink/af_netlink.c in the Linux kernel before 4.6.3 allows local users to cause a denial of service (double free) or possibly have unspecified other impact via a crafted application that makes sendmsg system calls, leading to a free operation associated with a new dump that started earlier than anticipated.

Patch / fix

fixed in 1 distros 4 links 4

linux linux_kernel 3.12.62, 3.14.73, 3.16.37, 3.18.37, 4.1.28, 4.4.14, 4.6.3

debian ubuntu red hat suse

linux Debian 14, Debian 13, Debian 12 4.6.3-1

debian advisories DEBIAN-CVE-2016-9806

linux Ubuntu 14.04 LTS 3.13.0-107.154
linux Ubuntu 16.04 LTS 4.4.0-34.53
linux-raspi2 Ubuntu 16.04 LTS 4.4.0-1019.25
linux-lts-vivid Ubuntu 14.04 LTS 3.19.0-79.87~14.04.1
linux-lts-xenial Ubuntu 14.04 LTS 4.4.0-34.53~14.04.1
linux-snapdragon Ubuntu 16.04 LTS 4.4.0-1022.25

ubuntu advisories UBUNTU-CVE-2016-9806

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

kernel-rt enterprise mrg 2 1:3.10.0-693.2.1.rt56.585.el6rt
kernel-rt-trace enterprise mrg 2 1:3.10.0-693.2.1.rt56.585.el6rt
kernel-rt-vanilla enterprise mrg 2 1:3.10.0-693.2.1.rt56.585.el6rt
kernel-rt-firmware enterprise mrg 2 1:3.10.0-693.2.1.rt56.585.el6rt
kernel-rt-debuginfo-common-x86_64 enterprise mrg 2 1:3.10.0-693.2.1.rt56.585.el6rt
kernel-rt RHEL 7 EXTRAS_RT 3.10.0-693.rt56.617.el7
kernel-rt-kvm RHEL 7 EXTRAS_RT 3.10.0-693.rt56.617.el7
kernel-rt-trace RHEL 7 EXTRAS_RT 3.10.0-693.rt56.617.el7

red hat advisories RHSA-2017:2669 RHSA-2017:2077 RHSA-2017:1842

kernel-syms SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2, SLES 12 SP2 +1 more 4.4.49-92.11.1
kernel-source SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2, SLES 12 SP2 +1 more 4.4.49-92.11.1
kernel-default SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2, SLES 12 SP2 +3 more 4.4.49-92.11.1
kernel-obs-build SLE Software Development Kit 12 SP2 4.4.49-92.11.1
kernel-ec2 SLE Module for Public Cloud 12 3.12.61-52.66.1
kernel-ec2 SLE Module for Public Cloud 12 3.12.69-60.64.29.1
kernel-xen SLES for SAP 12 SP1, SLES 12 SP1, SLED 12 SP1 3.12.69-60.64.29.1
kernel-syms SLES for SAP 12 SP1, SLES 12 SP1, SLED 12 SP1 3.12.69-60.64.29.1

suse advisories SUSE-SU-2017:0575-1 SUSE-SU-2017:0471-1 SUSE-SU-2017:0464-1 SUSE-SU-2017:0407-1 SUSE-SU-2017:0303-1 SUSE-SU-2017:0267-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-9806 updated 2026-11-05 cvss 7.8

kernel: netlink: double-free in netlink_dump

Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-693.el7, kernel 3.10.0-693.el7, python-perf 3.10.0-693.el7, kernel-tools 3.10.0-693.el7, kernel-tools-libs 3.10.0-693.el7, kernel-abi-whitelists 3.10.0-693.el7, +1 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-693.el7 Red Hat Enterprise Linux ComputeNode (v. 7) perf 3.10.0-693.el7, kernel 3.10.0-693.el7, python-perf 3.10.0-693.el7, kernel-tools 3.10.0-693.el7, kernel-tools-libs 3.10.0-693.el7, kernel-abi-whitelists 3.10.0-693.el7, +1 more Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-693.el7
fixed: vendor fix RHSA-2017:1842
Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-693.rt56.617.el7, kernel-rt-trace 3.10.0-693.rt56.617.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-693.rt56.617.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-693.rt56.617.el7, kernel-rt-kvm 3.10.0-693.rt56.617.el7, kernel-rt-trace 3.10.0-693.rt56.617.el7, kernel-rt-debug-kvm 3.10.0-693.rt56.617.el7, kernel-rt-trace-kvm 3.10.0-693.rt56.617.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-693.rt56.617.el7
fixed: vendor fix RHSA-2017:2077
Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-693.el7, kernel 3.10.0-693.el7, python-perf 3.10.0-693.el7, kernel-kdump 3.10.0-693.el7, kernel-tools 3.10.0-693.el7, kernel-tools-libs 3.10.0-693.el7, +6 more Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-693.el7, kernel-debuginfo-common-x86_64 3.10.0-693.el7, kernel-debuginfo-common-ppc64le 3.10.0-693.el7 Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-693.el7, kernel 3.10.0-693.el7, python-perf 3.10.0-693.el7, kernel-tools 3.10.0-693.el7, kernel-tools-libs 3.10.0-693.el7, kernel-abi-whitelists 3.10.0-693.el7, +1 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-693.el7
fixed: vendor fix RHSA-2017:1842
Red Hat MRG Realtime for RHEL 6 Server v.2 kernel-rt 3.10.0-693.2.1.rt56.585.el6rt, kernel-rt-trace 3.10.0-693.2.1.rt56.585.el6rt, kernel-rt-vanilla 3.10.0-693.2.1.rt56.585.el6rt, kernel-rt-firmware 3.10.0-693.2.1.rt56.585.el6rt, kernel-rt-debuginfo-common-x86_64 3.10.0-693.2.1.rt56.585.el6rt
fixed: vendor fix RHSA-2017:2669
Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux Client (v. 7) kernel-headers 3.10.0-693.el7 Red Hat Enterprise Linux ComputeNode (v. 7) kernel-headers 3.10.0-693.el7 Red Hat Enterprise Linux Server (v. 7) kernel-headers 3.10.0-693.el7 Red Hat Enterprise Linux Workstation (v. 7) kernel-headers 3.10.0-693.el7
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.2	AV:L/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness

CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
CWE-415 Double Free

Technology feeds

Linux kernel rss critical rss

References

github.com /torvalds/linux/commit/92964c79b357efd980812c4de5c1fd2ec8bb5520
patch, third-party-advisory
git.kernel.org /cgit/linux/kernel/git/torvalds/linux.git/commit/?id=92964c79b357efd980812c4de5c1fd2ec8bb5520
patch, vendor-advisory
openwall.com /lists/oss-security/2016/12/03/4
mailing-list, patch, third-party-advisory
bugzilla.redhat.com /show_bug.cgi?id=1401502
issue-tracking, patch
access.redhat.com /errata/RHSA-2017:2669
vendor-advisory, third-party-advisory
access.redhat.com /errata/RHSA-2017:2077
vendor-advisory, third-party-advisory
access.redhat.com /errata/RHSA-2017:1842
vendor-advisory, third-party-advisory
kernel.org /pub/linux/kernel/v4.x/ChangeLog-4.6.3
release-notes, vendor-advisory
securityfocus.com /bid/94653
vdb-entry, third-party-advisory
securitytracker.com /id/1037968
vdb-entry, third-party-advisory
lists.openwall.net /netdev/2016/05/15/69
mailing-list, third-party-advisory
source.android.com /security/bulletin/2017-03-01.html
third-party-advisory

Sources

CVE List CVE-2016-9806
NVD CVE-2016-9806

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary