From: Luis Vieira <luisflavieira@gmail.com>
To: Andrii Nakryiko <andrii@kernel.org>,
Eduard Zingerman <eddyz87@gmail.com>,
Ihor Solodrai <ihor.solodrai@linux.dev>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Martin KaFai Lau <martin.lau@linux.dev>,
Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
Jiri Olsa <jolsa@kernel.org>,
Emil Tsalapatis <emil@etsalapatis.com>
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
Luis Vieira <luisflavieira@gmail.com>
Subject: [PATCH bpf-next] libbpf: Validate ELF symbol table entry size
Date: Wed, 16 Sep 2026 18:23:35 -0300 [thread overview]
Message-ID: <20260916-libbpf-elf-entsize-fix-v1-1-cf181da33eab@gmail.com> (raw)
elf_sym_iter_new() calculates the number of symbols by dividing the
symbol table data size by sh_entsize. A malformed ELF file with a zero
sh_entsize causes a division by zero.
Reject symbol table sections with a zero entry size before calculating
the number of symbols.
Signed-off-by: Luis Vieira <luisflavieira@gmail.com>
---
tools/lib/bpf/elf.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/tools/lib/bpf/elf.c b/tools/lib/bpf/elf.c
index fe136d025967..ba0b3df37a59 100644
--- a/tools/lib/bpf/elf.c
+++ b/tools/lib/bpf/elf.c
@@ -118,6 +118,11 @@ static int elf_sym_iter_new(struct elf_sym_iter *iter,
if (!gelf_getshdr(scn, &sh))
return -EINVAL;
+ if (!sh.sh_entsize) {
+ pr_warn("elf: symbol table section has zero entry size in '%s'\n", binary_path);
+ return -EINVAL;
+ }
+
iter->strtabidx = sh.sh_link;
iter->syms = elf_getdata(scn, 0);
if (!iter->syms) {
---
base-commit: 10c4f610b215bf961235141161992f010cf7e451
change-id: 20260916-libbpf-elf-entsize-fix-a0f9440e79c7
Best regards,
--
Luis Vieira <luisflavieira@gmail.com>
next reply other threads:[~2026-09-16 21:23 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-16 21:23 Luis Vieira [this message]
2026-09-16 22:00 ` bot+bpf-ci
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