Linux Kernel: optkprobe Overlap Skip Disarmed Probes Vulnerability
CVE-2026-98856 Published on October 18, 2026
kprobes: Skip disarmed probes when checking optkprobe overlap
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.
Products Associated with CVE-2026-98856
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Affected Versions
Linux:- Version afd66255b9a48f5851326ddae50e2203fbf71dc9 and below 985a568171e7bdba6dcde3420d0e5bb515813457 is affected.
- Version afd66255b9a48f5851326ddae50e2203fbf71dc9 and below 6745fa65f4115045431c0c15610e876855a04625 is affected.
- Version afd66255b9a48f5851326ddae50e2203fbf71dc9 and below 526fac219e8b7d3369b43026bd0a1df51b811cd4 is affected.
- Version afd66255b9a48f5851326ddae50e2203fbf71dc9 and below 7a39c732a22ec4a369af9e19fbe3d666ec83eec4 is affected.
- Version 2.6.34 is affected.
- Before 2.6.34 is unaffected.
- Version 6.12.113, <= 6.12.* is unaffected.
- Version 6.18.56, <= 6.18.* is unaffected.
- Version 7.2.10, <= 7.2.* is unaffected.
- Version 7.3-rc6, <= * is unaffected.