fs/nfsd/trace.h in the Linux kernel before 5.13.4 might allow remote attackers to cause a denial of service (out-of-bounds read in strlen) by sending NFS traffic when the trace event framework is being used for nfsd.
https://security.netapp.com/advisory/ntap-20210902-0010/
https://github.com/torvalds/linux/commit/7b08cf62b1239a4322427d677ea9363f0ab677c6
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4