From: Ihor Solodrai Date: Thu, 10 Apr 2025 18:28:23 +0000 (-0700) Subject: libbpf: Verify section type in btf_find_elf_sections X-Git-Tag: v6.16-rc1~131^2~64 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=8582d9ab3efdebb88e0cd8beed8e0b9de76443e7;p=linux-block.git libbpf: Verify section type in btf_find_elf_sections A valid ELF file may contain a SHT_NOBITS .BTF section. This case is not handled correctly in btf_parse_elf, which leads to a segfault. Before attempting to load BTF section data, check that the section type is SHT_PROGBITS, which is the expected type for BTF data. Fail with an error if the type is different. Bug report: https://github.com/libbpf/libbpf/issues/894 v1: https://lore.kernel.org/bpf/20250408184104.3962949-1-ihor.solodrai@linux.dev/ Signed-off-by: Ihor Solodrai Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250410182823.1591681-1-ihor.solodrai@linux.dev --- diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 38bc6b14b066..24fc71ce5631 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -1148,6 +1148,12 @@ static int btf_find_elf_sections(Elf *elf, const char *path, struct btf_elf_secs else continue; + if (sh.sh_type != SHT_PROGBITS) { + pr_warn("unexpected section type (%d) of section(%d, %s) from %s\n", + sh.sh_type, idx, name, path); + goto err; + } + data = elf_getdata(scn, 0); if (!data) { pr_warn("failed to get section(%d, %s) data from %s\n",