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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Andrii Nakryiko <andriin@fb.com>,
        Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH 5.4 006/102] libbpf: Make btf__resolve_size logic always check size error condition
Date:   Fri, 24 Jan 2020 10:30:07 +0100
Message-Id: <20200124092807.027215215@linuxfoundation.org>
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From: Andrii Nakryiko <andriin@fb.com>

commit 994021a7e08477f7e51285920aac99fc967fae8a upstream.

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@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-5-andriin@fb.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 tools/lib/bpf/btf.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

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