diff options
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/btf.c | 50 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 25 |
2 files changed, 15 insertions, 60 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index be2104e5f2f5..33d9a1c73f6e 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6768,8 +6768,7 @@ int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *pr static int btf_check_func_arg_match(struct bpf_verifier_env *env, const struct btf *btf, u32 func_id, struct bpf_reg_state *regs, - bool ptr_to_mem_ok, - bool processing_call) + bool ptr_to_mem_ok) { enum bpf_prog_type prog_type = resolve_prog_type(env->prog); struct bpf_verifier_log *log = &env->log; @@ -6842,7 +6841,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, i, btf_type_str(t)); return -EINVAL; } - } else if (ptr_to_mem_ok && processing_call) { + } else if (ptr_to_mem_ok) { const struct btf_type *resolve_ret; u32 type_size; @@ -6867,55 +6866,12 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, return 0; } -/* Compare BTF of a function declaration with given bpf_reg_state. - * Returns: - * EFAULT - there is a verifier bug. Abort verification. - * EINVAL - there is a type mismatch or BTF is not available. - * 0 - BTF matches with what bpf_reg_state expects. - * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. - */ -int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, - struct bpf_reg_state *regs) -{ - struct bpf_prog *prog = env->prog; - struct btf *btf = prog->aux->btf; - bool is_global; - u32 btf_id; - int err; - - if (!prog->aux->func_info) - return -EINVAL; - - btf_id = prog->aux->func_info[subprog].type_id; - if (!btf_id) - return -EFAULT; - - if (prog->aux->func_info_aux[subprog].unreliable) - return -EINVAL; - - is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; - err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, false); - - /* Compiler optimizations can remove arguments from static functions - * or mismatched type can be passed into a global function. - * In such cases mark the function as unreliable from BTF point of view. - */ - if (err) - prog->aux->func_info_aux[subprog].unreliable = true; - return err; -} - /* Compare BTF of a function call with given bpf_reg_state. * Returns: * EFAULT - there is a verifier bug. Abort verification. * EINVAL - there is a type mismatch or BTF is not available. * 0 - BTF matches with what bpf_reg_state expects. * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. - * - * NOTE: the code is duplicated from btf_check_subprog_arg_match() - * because btf_check_func_arg_match() is still doing both. Once that - * function is split in 2, we can call from here btf_check_subprog_arg_match() - * first, and then treat the calling part in a new code path. */ int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog, struct bpf_reg_state *regs) @@ -6937,7 +6893,7 @@ int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog, return -EINVAL; is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; - err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, true); + err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global); /* Compiler optimizations can remove arguments from static functions * or mismatched type can be passed into a global function. diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 6555785b9f63..c26e9ab5226c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -19904,6 +19904,7 @@ static void free_states(struct bpf_verifier_env *env) static int do_check_common(struct bpf_verifier_env *env, int subprog) { bool pop_log = !(env->log.level & BPF_LOG_LEVEL2); + struct bpf_subprog_info *sub = subprog_info(env, subprog); struct bpf_verifier_state *state; struct bpf_reg_state *regs; int ret, i; @@ -19930,9 +19931,9 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog) state->first_insn_idx = env->subprog_info[subprog].start; state->last_insn_idx = -1; + regs = state->frame[state->curframe]->regs; if (subprog || env->prog->type == BPF_PROG_TYPE_EXT) { - struct bpf_subprog_info *sub = subprog_info(env, subprog); const char *sub_name = subprog_name(env, subprog); struct bpf_subprog_arg_info *arg; struct bpf_reg_state *reg; @@ -19979,21 +19980,19 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog) } } } else { + /* if main BPF program has associated BTF info, validate that + * it's matching expected signature, and otherwise mark BTF + * info for main program as unreliable + */ + if (env->prog->aux->func_info_aux) { + ret = btf_prepare_func_args(env, 0); + if (ret || sub->arg_cnt != 1 || sub->args[0].arg_type != ARG_PTR_TO_CTX) + env->prog->aux->func_info_aux[0].unreliable = true; + } + /* 1st arg to a function */ regs[BPF_REG_1].type = PTR_TO_CTX; mark_reg_known_zero(env, regs, BPF_REG_1); - ret = btf_check_subprog_arg_match(env, subprog, regs); - if (ret == -EFAULT) - /* unlikely verifier bug. abort. - * ret == 0 and ret < 0 are sadly acceptable for - * main() function due to backward compatibility. - * Like socket filter program may be written as: - * int bpf_prog(struct pt_regs *ctx) - * and never dereference that ctx in the program. - * 'struct pt_regs' is a type mismatch for socket - * filter that should be using 'struct __sk_buff'. - */ - goto out; } ret = do_check(env); |