From c18f0b6aee2aaa6ab2aefd4b9aa1d89142a48824 Mon Sep 17 00:00:00 2001 From: Lorenz Bauer Date: Mon, 21 Sep 2020 13:12:25 +0100 Subject: [PATCH] bpf: Check ARG_PTR_TO_SPINLOCK register type in check_func_arg Move the check for PTR_TO_MAP_VALUE to check_func_arg, where all other checking is done as well. Move the invocation of process_spin_lock away from the register type checking, to allow a future refactoring. Signed-off-by: Lorenz Bauer Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20200921121227.255763-10-lmb@cloudflare.com --- kernel/bpf/verifier.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 446fbe7f6b49..779091cb5bdd 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3828,10 +3828,6 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, struct bpf_map *map = reg->map_ptr; u64 val = reg->var_off.value; - if (reg->type != PTR_TO_MAP_VALUE) { - verbose(env, "R%d is not a pointer to map_value\n", regno); - return -EINVAL; - } if (!is_const) { verbose(env, "R%d doesn't have constant offset. bpf_spin_lock has to be at the constant offset\n", @@ -4040,16 +4036,9 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, if (type != expected_type) goto err_type; } else if (arg_type == ARG_PTR_TO_SPIN_LOCK) { - if (meta->func_id == BPF_FUNC_spin_lock) { - if (process_spin_lock(env, regno, true)) - return -EACCES; - } else if (meta->func_id == BPF_FUNC_spin_unlock) { - if (process_spin_lock(env, regno, false)) - return -EACCES; - } else { - verbose(env, "verifier internal error\n"); - return -EFAULT; - } + expected_type = PTR_TO_MAP_VALUE; + if (type != expected_type) + goto err_type; } else if (arg_type_is_mem_ptr(arg_type)) { expected_type = PTR_TO_STACK; /* One exception here. In case function allows for NULL to be @@ -4155,6 +4144,17 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, err = check_helper_mem_access(env, regno, meta->map_ptr->value_size, false, meta); + } else if (arg_type == ARG_PTR_TO_SPIN_LOCK) { + if (meta->func_id == BPF_FUNC_spin_lock) { + if (process_spin_lock(env, regno, true)) + return -EACCES; + } else if (meta->func_id == BPF_FUNC_spin_unlock) { + if (process_spin_lock(env, regno, false)) + return -EACCES; + } else { + verbose(env, "verifier internal error\n"); + return -EFAULT; + } } else if (arg_type_is_mem_ptr(arg_type)) { /* The access to this pointer is only checked when we hit the * next is_mem_size argument below. -- 2.17.1