A TOCTOU mismatch in the NFS client code in the Linux kernel before 5.8.3
could be used by local attackers to corrupt memory or possibly have
unspecified other impact because a size check is in fs/nfs/nfs4proc.c
instead of fs/nfs/nfs4xdr.c, aka CID-b4487b935452.

It was discovered that the NFS client implementation in the Linux kernel
did not properly perform bounds checking before copying security labels in
some situations. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code.