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From: Andrii Nakryiko <andriin@fb.com>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>,
	<daniel@iogearbox.net>
Cc: <andrii.nakryiko@gmail.com>, <kernel-team@fb.com>,
	Andrii Nakryiko <andriin@fb.com>
Subject: [PATCH bpf-next 4/5] libbpf: make btf__resolve_size logic always check size error condition
Date: Wed, 6 Nov 2019 18:08:54 -0800	[thread overview]
Message-ID: <20191107020855.3834758-5-andriin@fb.com> (raw)
In-Reply-To: <20191107020855.3834758-1-andriin@fb.com>

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>
---
 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


  parent reply	other threads:[~2019-11-07  2:09 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-07  2:08 [PATCH bpf-next 0/5] Fix bugs and issues found by static analysis in libbpf Andrii Nakryiko
2019-11-07  2:08 ` [PATCH bpf-next 1/5] libbpf: fix memory leak/double free issue Andrii Nakryiko
2019-11-07  2:08 ` [PATCH bpf-next 2/5] libbpf: fix potential overflow issue Andrii Nakryiko
2019-11-07  2:08 ` [PATCH bpf-next 3/5] libbpf: fix another potential overflow issue in bpf_prog_linfo Andrii Nakryiko
2019-11-07  2:08 ` Andrii Nakryiko [this message]
2019-11-07  2:08 ` [PATCH bpf-next 5/5] libbpf: improve handling of corrupted ELF during map initialization Andrii Nakryiko
2019-11-07 16:35 ` [PATCH bpf-next 0/5] Fix bugs and issues found by static analysis in libbpf Daniel Borkmann

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