From: Andrii Nakryiko Date: Mon, 28 Oct 2019 23:37:27 +0000 (-0700) Subject: libbpf: Fix off-by-one error in ELF sanity check X-Git-Tag: v5.5-rc1~174^2~249^2~12 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=d3a3aa0c59e83d8c13a758128b10dd459ce0d866;p=linux.git libbpf: Fix off-by-one error in ELF sanity check libbpf's bpf_object__elf_collect() does simple sanity check after iterating over all ELF sections, if checks that .strtab index is correct. Unfortunately, due to section indices being 1-based, the check breaks for cases when .strtab ends up being the very last section in ELF. Fixes: 77ba9a5b48a7 ("tools lib bpf: Fetch map names from correct strtab") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191028233727.1286699-1-andriin@fb.com --- diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index d71631a01926..5d15cc4dfcd6 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1664,7 +1664,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, bool relaxed_maps) } } - if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) { + if (!obj->efile.strtabidx || obj->efile.strtabidx > idx) { pr_warn("Corrupted ELF file: index of strtab invalid\n"); return -LIBBPF_ERRNO__FORMAT; }