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| author | Rhys Rustad-Elliott <me@rhysre.net> | 2023-06-02 21:02:02 +0200 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2023-06-03 01:22:12 +0200 |
| commit | cba41bb78d70aad98d8e61e019fd48c561f7f396 (patch) | |
| tree | 33e2676f60ac55a526f98eacd480303ab732e469 | |
| parent | bpf: Fix UAF in task local storage (diff) | |
| download | linux-cba41bb78d70aad98d8e61e019fd48c561f7f396.tar.xz linux-cba41bb78d70aad98d8e61e019fd48c561f7f396.zip | |
bpf: Fix elem_size not being set for inner maps
Commit d937bc3449fa ("bpf: make uniform use of array->elem_size
everywhere in arraymap.c") changed array_map_gen_lookup to use
array->elem_size instead of round_up(map->value_size, 8) as the element
size when generating code to access a value in an array map.
array->elem_size, however, is not set by bpf_map_meta_alloc when
initializing an BPF_MAP_TYPE_ARRAY_OF_MAPS or BPF_MAP_TYPE_HASH_OF_MAPS.
This results in array_map_gen_lookup incorrectly outputting code that
always accesses index 0 in the array (as the index will be calculated
via a multiplication with the element size, which is incorrectly set to
0).
Set elem_size on the bpf_array object when allocating an array or hash
of maps to fix this.
Fixes: d937bc3449fa ("bpf: make uniform use of array->elem_size everywhere in arraymap.c")
Signed-off-by: Rhys Rustad-Elliott <me@rhysre.net>
Link: https://lore.kernel.org/r/20230602190110.47068-2-me@rhysre.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
| -rw-r--r-- | kernel/bpf/map_in_map.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c index 2c5c64c2a53b..cd5eafaba97e 100644 --- a/kernel/bpf/map_in_map.c +++ b/kernel/bpf/map_in_map.c @@ -69,9 +69,13 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) /* Misc members not needed in bpf_map_meta_equal() check. */ inner_map_meta->ops = inner_map->ops; if (inner_map->ops == &array_map_ops) { + struct bpf_array *inner_array_meta = + container_of(inner_map_meta, struct bpf_array, map); + struct bpf_array *inner_array = container_of(inner_map, struct bpf_array, map); + + inner_array_meta->index_mask = inner_array->index_mask; + inner_array_meta->elem_size = inner_array->elem_size; inner_map_meta->bypass_spec_v1 = inner_map->bypass_spec_v1; - container_of(inner_map_meta, struct bpf_array, map)->index_mask = - container_of(inner_map, struct bpf_array, map)->index_mask; } fdput(f); |