CVE-2015-7513: Divide by Zero
arch/x86/kvm/x86.c in the Linux kernel before 4.4 does not reset the PIT counter values during state restoration, which allows guest OS users to cause a denial of service (divide-by-zero error and host OS crash) via a zero value, related to the kvmvmioctlsetpit and kvmvmioctlsetpit2 functions.
Other sources
Linux kernel built with the KVM virtualisation support(CONFIGKVM) is vulnerable to a divide by zero issue. It occurs in the KVM module's Programmable Interval Timer(PIT) emulation, when PIT counters for channel 1 or 2 are set to zero(0) and a privileged user inside guest attempts to read those.
A privileged guest user with access to PIT I/O ports, could use this issue to crash the host kernel resulting in DoS.
Upstream patch: --------------- -> https://git.kernel.org/linus/0185604c2d82c560dab2f2933a18f797e74ab5a8
Reference: ---------- -> http://www.openwall.com/lists/oss-security/2016/01/07/2 -> http://wiki.osdev.org/ProgrammableIntervalTimer -> http://www.osdever.net/bkerndev/Docs/pit.htm
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.135-1Fixed in 6.12.25-1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 3.13.0-77.121 - Upgrade
Upgrade
ubuntu/linux-lts-utopicto a version that resolves this vulnerability.Fixed in 3.16.0-60.80~14.04.1 - Upgrade
Upgrade
ubuntu/linux-lts-vividto a version that resolves this vulnerability.Fixed in 3.19.0-49.55~14.04.1 - Upgrade
Upgrade
ubuntu/linux-lts-wilyto a version that resolves this vulnerability.Fixed in 4.2.0-27.32~14.04.1 - Upgrade
Upgrade
Linux kernelto a version that resolves this vulnerability.Fixed in 4.4Patch 0185604c2d82c560dab2f2933a18f797e74ab5a8
Event History
Frequently Asked Questions
What is the vulnerability ID for this vulnerability?
The vulnerability ID for this vulnerability is CVE-2015-7513.
What is the severity level of CVE-2015-7513?
CVE-2015-7513 has a severity level of medium (4).
How does CVE-2015-7513 impact the Linux kernel?
CVE-2015-7513 allows guest OS users to cause a denial of service (divide-by-zero error and host OS crash) via a zero value.
Which versions of the Linux kernel are affected by CVE-2015-7513?
The Linux kernel versions before 4.4 are affected by CVE-2015-7513.
Are there any known solutions or remedies for CVE-2015-7513?
Yes, updating to Linux kernel version 4.4~ or later can mitigate CVE-2015-7513.