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.
https://git.kernel.org/stable/c/985a568171e7bdba6dcde3420d0e5bb515813457
https://git.kernel.org/stable/c/7a39c732a22ec4a369af9e19fbe3d666ec83eec4
https://git.kernel.org/stable/c/6745fa65f4115045431c0c15610e876855a04625
https://git.kernel.org/stable/c/526fac219e8b7d3369b43026bd0a1df51b811cd4