From 91571a515d1bcdc280bb46423bb697ea7eb42ff3 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 3 Apr 2023 21:50:25 -0700 Subject: bpf: Teach verifier that certain helpers accept NULL pointer. bpf_[sk|inode|task|cgrp]_storage_[get|delete]() and bpf_get_socket_cookie() helpers perform run-time check that sk|inode|task|cgrp pointer != NULL. Teach verifier about this fact and allow bpf programs to pass PTR_TO_BTF_ID | PTR_MAYBE_NULL into such helpers. It will be used in the subsequent patch that will do bpf_sk_storage_get(.., skb->sk, ...); Even when 'skb' pointer is trusted the 'sk' pointer may be NULL. Signed-off-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko Acked-by: David Vernet Link: https://lore.kernel.org/bpf/20230404045029.82870-5-alexei.starovoitov@gmail.com --- kernel/bpf/bpf_inode_storage.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/bpf/bpf_inode_storage.c') diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c index e17ad581b9be..a4d93df78c75 100644 --- a/kernel/bpf/bpf_inode_storage.c +++ b/kernel/bpf/bpf_inode_storage.c @@ -229,7 +229,7 @@ const struct bpf_func_proto bpf_inode_storage_get_proto = { .gpl_only = false, .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, .arg1_type = ARG_CONST_MAP_PTR, - .arg2_type = ARG_PTR_TO_BTF_ID, + .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL, .arg2_btf_id = &bpf_inode_storage_btf_ids[0], .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL, .arg4_type = ARG_ANYTHING, @@ -240,6 +240,6 @@ const struct bpf_func_proto bpf_inode_storage_delete_proto = { .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_CONST_MAP_PTR, - .arg2_type = ARG_PTR_TO_BTF_ID, + .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL, .arg2_btf_id = &bpf_inode_storage_btf_ids[0], }; -- cgit