On 10/06, Kees Cook wrote: > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for > array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > As found with Coccinelle[1], add __counted_by for struct bpf_stack_map. > > Cc: Song Liu <song@xxxxxxxxxx> > Cc: Jiri Olsa <jolsa@xxxxxxxxxx> > Cc: Alexei Starovoitov <ast@xxxxxxxxxx> > Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx> > Cc: Andrii Nakryiko <andrii@xxxxxxxxxx> > Cc: Martin KaFai Lau <martin.lau@xxxxxxxxx> > Cc: Yonghong Song <yonghong.song@xxxxxxxxx> > Cc: John Fastabend <john.fastabend@xxxxxxxxx> > Cc: KP Singh <kpsingh@xxxxxxxxxx> > Cc: Stanislav Fomichev <sdf@xxxxxxxxxx> > Cc: Hao Luo <haoluo@xxxxxxxxxx> > Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx> > Cc: bpf@xxxxxxxxxxxxxxx > Cc: linux-hardening@xxxxxxxxxxxxxxx > Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1] > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> TIL about __counted_by :-) Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxx> > --- > kernel/bpf/stackmap.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c > index 458bb80b14d5..d6b277482085 100644 > --- a/kernel/bpf/stackmap.c > +++ b/kernel/bpf/stackmap.c > @@ -28,7 +28,7 @@ struct bpf_stack_map { > void *elems; > struct pcpu_freelist freelist; > u32 n_buckets; > - struct stack_map_bucket *buckets[]; > + struct stack_map_bucket *buckets[] __counted_by(n_buckets); > }; > > static inline bool stack_map_use_build_id(struct bpf_map *map) > -- > 2.34.1 >
