CWE
835
EPSS
0.045%
Advisory Published
Updated

CVE-2024-26603: x86/fpu: Stop relying on userspace for info to fault in xsave buffer

First published: Sat Feb 24 2024(Updated: )

In the Linux kernel, the following vulnerability has been resolved: x86/fpu: Stop relying on userspace for info to fault in xsave buffer Before this change, the expected size of the user space buffer was taken from fx_sw->xstate_size. fx_sw->xstate_size can be changed from user-space, so it is possible construct a sigreturn frame where: * fx_sw->xstate_size is smaller than the size required by valid bits in fx_sw->xfeatures. * user-space unmaps parts of the sigrame fpu buffer so that not all of the buffer required by xrstor is accessible. In this case, xrstor tries to restore and accesses the unmapped area which results in a fault. But fault_in_readable succeeds because buf + fx_sw->xstate_size is within the still mapped area, so it goes back and tries xrstor again. It will spin in this loop forever. Instead, fault in the maximum size which can be touched by XRSTOR (taken from fpstate->user_size). [ dhansen: tweak subject / changelog ]

Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Affected SoftwareAffected VersionHow to fix
Linux Linux kernel>=5.14.0<5.15.150
Linux Linux kernel>=5.16.0<6.1.79
Linux Linux kernel>=6.2.0<6.6.18
Linux Linux kernel>=6.7.0<6.7.6
redhat/kernel<6.1.79
6.1.79
redhat/kernel<6.6.18
6.6.18
redhat/kernel<6.7.6
6.7.6
redhat/kernel<6.8
6.8
debian/linux
5.10.223-1
5.10.226-1
6.1.115-1
6.1.119-1
6.12.5-1
6.12.6-1

Never miss a vulnerability like this again

Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2024 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203