In the Linux kernel, following vulnerability has been resolved: rseq: Fix segfault on registration when rseq_cs is non-zero The field documented as being set to 0 by user-space prior to registration, however this not currently enforced kernel. This can result in a return if value stored in the doesn't point valid struct rseq_cs. The correct solution would be fail rseq when the non-zero. However, some older versions of glibc will reuse area previous threads without clearing the rseq_cs and will also terminate process rseq registration fails secondary thread. This wasn't caught testing because case leftover does struct rseq_cs. What we can do clear it's non-zero which prevent segfaults won't break the glibc that areas thread creation.