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 ]
Advisories
Source ID Title
Debian DSA Debian DSA DSA-5658-1 linux security update
Ubuntu USN Ubuntu USN USN-6820-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6820-2 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-3 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-4 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-6828-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-6871-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-6892-1 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6900-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6919-1 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 04 Nov 2025 19:30:00 +0000


Mon, 10 Mar 2025 15:15:00 +0000

Type Values Removed Values Added
First Time appeared Redhat rhel Eus
CPEs cpe:/a:redhat:rhel_eus:9.4
Vendors & Products Redhat rhel Eus

Wed, 13 Nov 2024 02:45:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-11-04T18:29:51.152Z

Reserved: 2024-02-19T14:20:24.129Z

Link: CVE-2024-26603

cve-icon Vulnrichment

Updated: 2024-08-02T00:07:19.584Z

cve-icon NVD

Status : Modified

Published: 2024-02-26T16:28:00.097

Modified: 2025-11-04T19:17:02.170

Link: CVE-2024-26603

cve-icon Redhat

Severity : Low

Publid Date: 2024-02-24T00:00:00Z

Links: CVE-2024-26603 - Bugzilla

cve-icon OpenCVE Enrichment

No data.