Commit e181d3f1 authored Nov 21, 2022 by Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov Nov 20, 2022

bpf: Disallow bpf_obj_new_impl call when bpf_mem_alloc_init fails



In the unlikely event that bpf_global_ma is not correctly initialized,
instead of checking the boolean everytime bpf_obj_new_impl is called,
simply check it while loading the program and return an error if
bpf_global_ma_set is false.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221120212610.2361700-1-memxor@gmail.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>

parent efc1970d

kernel/bpf/helpers.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -1760,8 +1760,6 @@ void bpf_obj_new_impl(u64 local_type_id__k, void meta__ign)
		u64 size = local_type_id__k;
		void *p;

		if (unlikely(!bpf_global_ma_set))
		return NULL;
		p = bpf_mem_alloc(&bpf_global_ma, size);
		if (!p)
		return NULL;

kernel/bpf/verifier.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -8878,6 +8878,9 @@ static int check_kfunc_call(struct bpf_verifier_env env, struct bpf_insn insn,
		struct btf *ret_btf;
		u32 ret_btf_id;

		if (unlikely(!bpf_global_ma_set))
		return -ENOMEM;

		if (((u64)(u32)meta.arg_constant.value) != meta.arg_constant.value) {
		verbose(env, "local type ID argument must be in range [0, U32_MAX]\n");
		return -EINVAL;