diff options
| author | Andreas Ziegler <ziegler.andreas@siemens.com> | 2024-07-03 10:34:36 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-09-12 11:13:00 +0200 |
| commit | 9feed1c5260cf1d161dea7a56a28d2dfa0cfa48a (patch) | |
| tree | f21d99e12ed0d7c98e9640aa8628460bcdbc541e | |
| parent | 899eddc06e026ec6e4ebe13fe76f503caad89f80 (diff) | |
libbpf: Add NULL checks to bpf_object__{prev_map,next_map}
[ Upstream commit cedc12c5b57f7efa6dbebfb2b140e8675f5a2616 ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 5401f2df463d2..5edb717647847 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -10336,7 +10336,7 @@ __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); @@ -10345,7 +10345,7 @@ 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; |