Bug 1529302 (CVE-2017-15537)

Summary:	CVE-2017-15537 kernel: Information leak of x86 FPU registers
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	airlied, ajax, aquini, bhu, blc, bskeggs, dhoward, dmoppert, dominik.mierzejewski, esammons, ewk, fhrbata, hdegoede, hkrzesin, hwkernel-mgr, iboverma, ichavero, itamar, jarodwilson, jforbes, jglisse, jkacur, john.j5live, jonathan, josef, jross, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, lwang, matt, mchehab, mcressma, mguzik, mjg59, mlangsdo, nmurray, plougher, rt-maint, rvrbovsk, skozina, steved, vdronov, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	The x86/fpu (Floating Point Unit) subsystem in the Linux kernel, when a processor supports the xsave feature but not the xsaves feature, does not correctly handle attempts to set reserved bits in the xstate header via the ptrace() or rt_sigreturn() system call. This allows local users to read the FPU registers of other processes on the system, related to arch/x86/kernel/fpu/regset.c and arch/x86/kernel/fpu/signal.c.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-03-19 15:31:34 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1529303
Bug Blocks:	1529304

Description Pedro Sampaio 2017-12-27 14:59:40 UTC

The x86/fpu (Floating Point Unit) subsystem in the Linux kernel, when a processor supports the xsave feature but not the xsaves feature, does not correctly handle attempts to set reserved bits in the xstate header via the ptrace() or rt_sigreturn() system call, allowing local users to read the FPU registers of other processes on the system, related to arch/x86/kernel/fpu/regset.c and arch/x86/kernel/fpu/signal.c.

References:

https://marc.info/?t=150610240800004&r=1&w=2

https://marc.info/?l=linux-kernel&m=150617182112114

An upsteam patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=814fb7bb7db5433757d76f4c4502c96fc53b0b5e

Comment 1 Pedro Sampaio 2017-12-27 15:00:15 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1529303]

Comment 2 Justin M. Forbes 2018-01-02 14:29:28 UTC

This was fixed for Fedora with the 4.13.5 stable update on 10/10/2017