netdev - [PATCH bpf-next 4/5] libbpf: make btf__resolve_size logic always check size error condition

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Date:   Wed, 6 Nov 2019 18:08:54 -0800
From:   Andrii Nakryiko <andriin@...com>
To:     <bpf@...r.kernel.org>, <netdev@...r.kernel.org>, <ast@...com>,
        <daniel@...earbox.net>
CC:     <andrii.nakryiko@...il.com>, <kernel-team@...com>,
        Andrii Nakryiko <andriin@...com>
Subject: [PATCH bpf-next 4/5] libbpf: make btf__resolve_size logic always check size error condition

Perform size check always in btf__resolve_size. Makes the logic a bit more
robust against corrupted BTF and silences LGTM/Coverity complaining about
always true (size < 0) check.

Fixes: 69eaab04c675 ("btf: extract BTF type size calculation")
Signed-off-by: Andrii Nakryiko <andriin@...com>
---
 tools/lib/bpf/btf.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index d72e9a79dce1..86a1847e4a9f 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -269,10 +269,9 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
 		t = btf__type_by_id(btf, type_id);
 	}
 
+done:
 	if (size < 0)
 		return -EINVAL;
-
-done:
 	if (nelems && size > UINT32_MAX / nelems)
 		return -E2BIG;
 
-- 
2.17.1