Description
The restore_fpu_checking function in arch/x86/include/asm/fpu-internal.h in the Linux kernel before 3.12.8 on the AMD K7 and K8 platforms does not clear pending exceptions before proceeding to an EMMS instruction, which allows local users to cause a denial of service (task kill) or possibly gain privileges via a crafted application.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 3.12.8-1 | — |
| Debian 13 | linux | 3.12.8-1 | — |
| Debian 12 | linux | 3.12.8-1 | — |
| Debian 6.0 | linux-2.6 | 2.6.32-48squeeze7 | DLA-0007-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat MRG 2 | kernel-rt +10 | 3.10.33-rt32.33.el6rt | RHSA-2014:0439 |
Advisories 2
- DLA-0007-1 linux-2.6 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RHSA-2014:0439 Red Hat Security Advisory: kernel-rt security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jan 7, 2026
References
- USN-2135-1 vendor-advisory
- USN-2138-1 vendor-advisory
- USN-2113-1 vendor-advisory
- USN-2141-1 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1052914
- [oss-security] 20140114 Re: Linux kernel: missing CPU-state sanitation during task-switch causes DOS / privilege escalation mailing-list
- USN-2136-1 vendor-advisory
- 64781 vdb-entry
- USN-2139-1 vendor-advisory
- FEDORA-2014-1062 vendor-advisory
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=26bef1318adc1b3a530ecc807ef99346db2aa8b0
- USN-2134-1 vendor-advisory
- http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.12.8
- MDVSA-2014:038 vendor-advisory
- USN-2117-1 vendor-advisory
- https://github.com/torvalds/linux/commit/26bef1318adc1b3a530ecc807ef99346db2aa8b0
- USN-2133-1 vendor-advisory
- 1029592 vdb-entry
- FEDORA-2014-1072 vendor-advisory
- [linux-kernel] 20140110 Re: Sanitize CPU-state when switching tasks (was sanitize CPU-state when switching from virtual-8086 mode to other task) mailing-list
- http://www.halfdog.net/Security/2013/Vm86SyscallTaskSwitchKernelPanic/