Debian DLA-833-1 : linux security update
High Nessus Plugin ID 97332
SynopsisThe remote Debian host is missing a security update.
DescriptionSeveral vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or have other impacts.
Russell King found that on ARM systems, memory allocated for DMA buffers was mapped with executable permission. This made it easier to exploit other vulnerabilities in the kernel.
Dan Carpenter found that the MEDIA_IOC_ENUM_LINKS ioctl on media devices resulted in an information leak.
CVE-2016-6786 / CVE-2016-6787
It was discovered that the performance events subsystem does not properly manage locks during certain migrations, allowing a local attacker to escalate privileges. This can be mitigated by disabling unprivileged use of performance events: sysctl kernel.perf_event_paranoid=3
Peter Pi of Trend Micro discovered that the frame buffer video subsystem does not properly check bounds while copying color maps to userspace, causing a heap buffer out-of-bounds read, leading to information disclosure.
It was discovered that the KLSI KL5KUSB105 serial USB device driver could log the contents of uninitialised kernel memory, resulting in an information leak.
Di Shen discovered a race condition between concurrent calls to the performance events subsystem, allowing a local attacker to escalate privileges. This flaw exists because of an incomplete fix of CVE-2016-6786. This can be mitigated by disabling unprivileged use of performance events: sysctl kernel.perf_event_paranoid=3
Andrey Konovalov discovered a use-after-free vulnerability in the DCCP networking code, which could result in denial of service or local privilege escalation. On systems that do not already have the dccp module loaded, this can be mitigated by disabling it: echo >> /etc/modprobe.d/disable-dccp.conf install dccp false
For Debian 7 'Wheezy', these problems have been fixed in version 3.2.84-2.
For Debian 8 'Jessie', these problems have been fixed in version 3.16.39-1+deb8u1 or earlier.
We recommend that you upgrade your linux packages.
NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpgrade the affected linux package.