x86/fpu: Stop relying on userspace for info to fault in xsave buffer
Priority LOW 25CWE-835Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-835.
Summary
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 ]
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00278 20th percentileScored 2026-11-07
Fix Fixed Linux (Linux): 5.15.150, 6.1.79, 6.6.18 +2Red Hat: 4 advisories
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.14 and later | 5.15.150, 6.1.79, 6.6.18, 6.7.6, 6.8 | Patch available | CNA |
- Linux VendorLinux Affected 5.14 and later Fixed in 5.15.150, 6.1.79, 6.6.18, 6.7.6, 6.8 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.14.0 to before 5.15.150; 5.16.0 to before 6.1.79; 6.2.0 to before 6.6.18; 6.7.0 to before 6.7.6 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.14.0 to before 5.15.150; 5.16.0 to before 6.1.79; 6.2.0 to before 6.6.18; 6.7.0 to before 6.7.6 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.15.150, 6.1.79, 6.6.18, 6.7.6, 6.8
Red Hat 4 advisories
- RHSA-2025:2490 Released 2025-03-10 · Red Hat rating Importantkernel security update
- Red Hat CodeReady Linux Builder EUS (v.9.4) kernel-tools-libs-devel-5.14.0-427.59.1.el9_4, libperf-5.14.0-427.59.1.el9_4
- Red Hat Enterprise Linux AppStream EUS (v.9.4) kernel-64k-debug-devel-5.14.0-427.59.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.59.1.el9_4, kernel-64k-devel-5.14.0-427.59.1.el9_4 +11
- Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool-7.3.0-427.59.1.el9_4, kernel-5.14.0-427.59.1.el9_4, kernel-64k-5.14.0-427.59.1.el9_4 +29
- Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt-5.14.0-427.59.1.el9_4, kernel-rt-core-5.14.0-427.59.1.el9_4, kernel-rt-debug-5.14.0-427.59.1.el9_4 +9
- Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt-5.14.0-427.59.1.el9_4, kernel-rt-core-5.14.0-427.59.1.el9_4, kernel-rt-debug-5.14.0-427.59.1.el9_4 +11
- RHSA-2024:9315 Released 2024-11-12 · Red Hat rating Moderatekernel security update
- Red Hat CodeReady Linux Builder (v. 9) kernel-cross-headers-5.14.0-503.11.1.el9_5, kernel-tools-libs-devel-5.14.0-503.11.1.el9_5, libperf-5.14.0-503.11.1.el9_5
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-503.11.1.el9_5, kernel-64k-debug-devel-matched-5.14.0-503.11.1.el9_5, kernel-64k-devel-5.14.0-503.11.1.el9_5 +12
- Red Hat Enterprise Linux BaseOS (v. 9) bpftool-7.4.0-503.11.1.el9_5, kernel-5.14.0-503.11.1.el9_5, kernel-64k-5.14.0-503.11.1.el9_5 +30
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-503.11.1.el9_5, kernel-rt-core-5.14.0-503.11.1.el9_5, kernel-rt-debug-5.14.0-503.11.1.el9_5 +9
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-503.11.1.el9_5, kernel-rt-core-5.14.0-503.11.1.el9_5, kernel-rt-debug-5.14.0-503.11.1.el9_5 +11
- RHSA-2024:3627 Released 2024-06-05 · Red Hat rating Moderatekernel-rt security and bug fix update
- Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-core-4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-debug-4.18.0-553.5.1.rt7.346.el8_10 +9
- Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-core-4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-debug-4.18.0-553.5.1.rt7.346.el8_10 +7
Show 1 more Red Hat advisories
- RHSA-2024:3618 Released 2024-06-05 · Red Hat rating Moderatekernel update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.5.1.el8_10, kernel-4.18.0-553.5.1.el8_10, kernel-abi-stablelists-4.18.0-553.5.1.el8_10 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.5.1.el8_10
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat CodeReady Linux Builder (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat CodeReady Linux Builder EUS (v.9.4) | Fixed | RHSA-2025:2490 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux AppStream EUS (v.9.4) | Fixed | RHSA-2025:2490 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2024:3618 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux BaseOS EUS (v.9.4) | Fixed | RHSA-2025:2490 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2024:3618 |
| Red Hat Enterprise Linux NFV (v. 8) | Fixed | RHSA-2024:3627 |
| Red Hat Enterprise Linux RT (v. 8) | Fixed | RHSA-2024:3627 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux Real Time EUS (v.9.4) | Fixed | RHSA-2025:2490 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) | Fixed | RHSA-2025:2490 |
Not affected: 4 products
- Red Hat CodeReady Linux Builder (v. 9)
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux AppStream (v. 9)
Timeline
- 2026-10-02 Threatist record created from CVE-2024-26603
- 2026-10-03 Alias added: GHSA-fq97-hv4f-crm6
- 2026-10-29 Affected versions changed · Red Hat
References
Patch 5
- https://git.kernel.org/stable/c/8bd3eee7720c14b59a206bd05b98d7586bccf99a
- https://git.kernel.org/stable/c/627339cccdc9166792ecf96bc3c9f711a60ce996
- https://git.kernel.org/stable/c/b2479ab426cef7ab79a13005650eff956223ced2
- https://git.kernel.org/stable/c/627e28cbb65564e55008315d9e02fbb90478beda
- https://git.kernel.org/stable/c/d877550eaf2dc9090d782864c96939397a3c6835
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2024-26603 · CVE Program
- CVE-2024-26603 · NVD
- FIRST EPSS
- GHSA-fq97-hv4f-crm6 · GitHub Advisory Database · CC BY 4.0
- CVE-2024-26603 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences