libbpf/backport-libbpf-Add-NULL-checks-to-bpf_object__prev_map,next_.patch
zhang-mingyi66 246f68069b backport patches from upstream:
backport-libbpf-Add-NULL-checks-to-bpf_object__prev_map,next_.patch
backport-libbpf-Apply-map_set_def_max_entries-for-inner_maps-.patch

Signed-off-by: zhang-mingyi66 <zhangmingyi5@huawei.com>
(cherry picked from commit 036cf1a87e3060b88baacc592c7e96a57f88fa5b)
2024-10-12 09:13:32 +08:00

54 lines
1.9 KiB
Diff

From 1867490d8fc635c552569d51c48debff588d2191 Mon Sep 17 00:00:00 2001
From: Andreas Ziegler <ziegler.andreas@siemens.com>
Date: Wed, 3 Jul 2024 10:34:36 +0200
Subject: [PATCH] libbpf: Add NULL checks to bpf_object__{prev_map,next_map}
In the current state, an erroneous call to
bpf_object__find_map_by_name(NULL, ...) leads to a segmentation
fault through the following call chain:
bpf_object__find_map_by_name(obj = NULL, ...)
-> bpf_object__for_each_map(pos, obj = NULL)
-> bpf_object__next_map((obj = NULL), NULL)
-> return (obj = NULL)->maps
While calling bpf_object__find_map_by_name with obj = NULL is
obviously incorrect, this should not lead to a segmentation
fault but rather be handled gracefully.
As __bpf_map__iter already handles this situation correctly, we
can delegate the check for the regular case there and only add
a check in case the prev or next parameter is NULL.
Signed-off-by: Andreas Ziegler <ziegler.andreas@siemens.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240703083436.505124-1-ziegler.andreas@siemens.com
---
src/libbpf.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/libbpf.c b/src/libbpf.c
index 4a28fac49..30f121754 100644
--- a/src/libbpf.c
+++ b/src/libbpf.c
@@ -10375,7 +10375,7 @@ __bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i)
struct bpf_map *
bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev)
{
- if (prev == NULL)
+ if (prev == NULL && obj != NULL)
return obj->maps;
return __bpf_map__iter(prev, obj, 1);
@@ -10384,7 +10384,7 @@ bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev)
struct bpf_map *
bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *next)
{
- if (next == NULL) {
+ if (next == NULL && obj != NULL) {
if (!obj->nr_maps)
return NULL;
return obj->maps + obj->nr_maps - 1;
--
2.33.0