From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org, netdev@vger.kernel.org,
"Toke Høiland-Jørgensen" <toke@redhat.com>
Subject: [PATCH bpf v2] libbpf: don't crash on object files with no symbol tables
Date: Wed, 1 Sep 2021 13:48:12 +0200 [thread overview]
Message-ID: <20210901114812.204720-1-toke@redhat.com> (raw)
If libbpf encounters an ELF file that has been stripped of its symbol
table, it will crash in bpf_object__add_programs() when trying to
dereference the obj->efile.symbols pointer.
Fix this by erroring out of bpf_object__elf_collect() if it is not able
able to find the symbol table.
v2:
- Move check into bpf_object__elf_collect() and add nice error message
Fixes: 6245947c1b3c ("libbpf: Allow gaps in BPF program sections to support overriden weak functions")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
---
tools/lib/bpf/libbpf.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 6f5e2757bb3c..997060182cef 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2990,6 +2990,12 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
}
}
+ if (!obj->efile.symbols) {
+ pr_warn("elf: couldn't find symbol table in %s - stripped object file?\n",
+ obj->path);
+ return -ENOENT;
+ }
+
scn = NULL;
while ((scn = elf_nextscn(elf, scn)) != NULL) {
idx++;
--
2.33.0
next reply other threads:[~2021-09-01 11:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-01 11:48 Toke Høiland-Jørgensen [this message]
2021-09-08 0:30 ` [PATCH bpf v2] libbpf: don't crash on object files with no symbol tables Andrii Nakryiko
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