From: "Daniel T. Lee" <danieltimlee@gmail.com>
Date: Thu, 6 Aug 2020 07:33:59 +0900
Subject: libbf: Fix uninitialized pointer at btf__parse_raw()
Patch-mainline: v5.9-rc1
Git-commit: 932ac54a3e59335a847f7682b5124a788ab3c798
References: bsc#1177028

Recently, from commit 94a1fedd63ed ("libbpf: Add btf__parse_raw() and
generic btf__parse() APIs"), new API has been added to libbpf that
allows to parse BTF from raw data file (btf__parse_raw()).

The commit derives build failure of samples/bpf due to improper access
of uninitialized pointer at btf_parse_raw().

    btf.c: In function btf__parse_raw:
    btf.c:625:28: error: btf may be used uninitialized in this function
      625 |  return err ? ERR_PTR(err) : btf;
          |         ~~~~~~~~~~~~~~~~~~~^~~~~

This commit fixes the build failure of samples/bpf by adding code of
initializing btf pointer as NULL.

Fixes: 94a1fedd63ed ("libbpf: Add btf__parse_raw() and generic btf__parse() APIs")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200805223359.32109-1-danieltimlee@gmail.com
Acked-by: Gary Lin <glin@suse.com>
---
 tools/lib/bpf/btf.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -564,8 +564,8 @@ done:
 
 struct btf *btf__parse_raw(const char *path)
 {
+	struct btf *btf = NULL;
 	void *data = NULL;
-	struct btf *btf;
 	FILE *f = NULL;
 	__u16 magic;
 	int err = 0;