diff options
| author | Andreas Ziegler <ziegler.andreas@siemens.com> | 2024-07-03 10:34:36 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2024-07-08 18:13:07 +0200 |
| commit | cedc12c5b57f7efa6dbebfb2b140e8675f5a2616 (patch) | |
| tree | 3465b787ffaef87b551ab865061c932184ca5ab3 /tools/lib | |
| parent | 02480fe8a6a6d44c16900b1d3a2a66d140d0a005 (diff) | |
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
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 4a28fac4908a..30f121754d83 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/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; |