Add the __counted_by compiler attribute to the flexible array member cands to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE.
Increment cnt before adding a new struct to the cands array. Signed-off-by: Thorsten Blum <[email protected]> --- kernel/bpf/btf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 520f49f422fe..42bc70a56fcd 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -7240,7 +7240,7 @@ struct bpf_cand_cache { struct { const struct btf *btf; u32 id; - } cands[]; + } cands[] __counted_by(cnt); }; static DEFINE_MUTEX(cand_cache_mutex); @@ -8784,9 +8784,9 @@ bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf, memcpy(new_cands, cands, sizeof_cands(cands->cnt)); bpf_free_cands(cands); cands = new_cands; - cands->cands[cands->cnt].btf = targ_btf; - cands->cands[cands->cnt].id = i; cands->cnt++; + cands->cands[cands->cnt - 1].btf = targ_btf; + cands->cands[cands->cnt - 1].id = i; } return cands; } -- 2.46.0
