nf_tables_newset in net/netfilter/nf_tables_api.c in the Linux kernel before 5.12.13 allows local users to cause a denial of service (NULL pointer dereference and general protection fault) because of the missing initialization for nft_set_elem_expr_alloc. A local user can set a netfilter table expression in their own namespace.
https://syzkaller.appspot.com/bug?id=22c3987f75a7b90e238a26b5a5920525c2d1f345
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.13