From: Michael Mullin <masmullin@gmail.com>
Date: Mon, 23 May 2022 19:49:17 +0000 (-0400)
Subject: bpftool: Check for NULL ptr of btf in codegen_asserts
X-Git-Tag: block-6.0-2022-08-12~31^2~339^2~28
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=de4b4b94fad90f876ab12e87999109e31a1871b4;p=linux-block.git

bpftool: Check for NULL ptr of btf in codegen_asserts

bpf_object__btf() can return a NULL value.  If bpf_object__btf returns
null, do not progress through codegen_asserts(). This avoids a null ptr
dereference at the call btf__type_cnt() in the function find_type_for_map()

Signed-off-by: Michael Mullin <masmullin@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220523194917.igkgorco42537arb@jup
---

diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 4c9477ff748d..f158dc1c2149 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -474,6 +474,9 @@ static void codegen_asserts(struct bpf_object *obj, const char *obj_name)
 	const struct btf_type *sec;
 	char map_ident[256], var_ident[256];
 
+	if (!btf)
+		return;
+
 	codegen("\
 		\n\
 		__attribute__((unused)) static void			    \n\