In the Linux kernel, the following vulnerability has been resolved:

kprobes: Skip disarmed probes when checking optkprobe overlap

On x86, an optkprobe at A replaces five bytes with a jump. If a disabled
probe B is at A+2, get_optimized_kprobe() stops at B when arming a new
probe C at A+4. It leaves A optimized:

A A+1 A+2 A+3 A+4
A's jump | e9 | d0 | d1 | d2 | d3 |
after C | e9 | d0 | d1 | d2 | cc |

The INT3 for C overwrites the last byte of A's jump displacement, so
execution can jump to the wrong address. B can have prepared optinsns
while disarmed, but has no jump to unoptimize.

Continue past disarmed and unprepared probes to find the active optimized
probe before arming a probe in its jump.
Advisories

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Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Sun, 18 Oct 2026 21:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20

Sun, 18 Oct 2026 16:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: kprobes: Skip disarmed probes when checking optkprobe overlap On x86, an optkprobe at A replaces five bytes with a jump. If a disabled probe B is at A+2, get_optimized_kprobe() stops at B when arming a new probe C at A+4. It leaves A optimized: A A+1 A+2 A+3 A+4 A's jump | e9 | d0 | d1 | d2 | d3 | after C | e9 | d0 | d1 | d2 | cc | The INT3 for C overwrites the last byte of A's jump displacement, so execution can jump to the wrong address. B can have prepared optinsns while disarmed, but has no jump to unoptimize. Continue past disarmed and unprepared probes to find the active optimized probe before arming a probe in its jump.
Title kprobes: Skip disarmed probes when checking optkprobe overlap
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-18T15:51:12.359Z

Reserved: 2026-09-25T10:25:14.376Z

Link: CVE-2026-98856

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T16:17:40.050

Modified: 2026-10-18T16:17:40.050

Link: CVE-2026-98856

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-18T21:15:14Z

Weaknesses