bpf: Handle allocation failure in acquire_lock_state

The acquire_lock_state function needs to handle possible NULL values
returned by acquire_reference_state, and return -ENOMEM.

Fixes: 769b0f1 ("bpf: Refactor {acquire,release}_reference_state")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250206105435.2159977-24-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Author: kkdwivedi

kernel/bpf/verifier.c

@@ -1501,6 +1501,8 @@ static int acquire_lock_state(struct bpf_verifier_env *env, int insn_idx, enum r
 	struct bpf_reference_state *s;
 
 	s = acquire_reference_state(env, insn_idx);
+	if (!s)
+		return -ENOMEM;
 	s->type = type;
 	s->id = id;
 	s->ptr = ptr;