From: Lorenz Bauer <lmb@cloudflare.com>
To: ast@kernel.org, yhs@fb.com, daniel@iogearbox.net, kafai@fb.com
Cc: bpf@vger.kernel.org, kernel-team@cloudflare.com,
Lorenz Bauer <lmb@cloudflare.com>
Subject: [PATCH bpf-next 09/11] bpf: check ARG_PTR_TO_SPINLOCK register type in check_func_arg
Date: Fri, 4 Sep 2020 12:23:59 +0100 [thread overview]
Message-ID: <20200904112401.667645-10-lmb@cloudflare.com> (raw)
In-Reply-To: <20200904112401.667645-1-lmb@cloudflare.com>
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 <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 734ae5af9db9..8d060da0b068 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3781,10 +3781,6 @@ 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",
@@ -4000,16 +3996,9 @@ 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
@@ -4119,6 +4108,17 @@ 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.
--
2.25.1
next prev parent reply other threads:[~2020-09-04 11:29 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-04 11:23 [PATCH bpf-next 00/11] RFC: Make check_func_arg table driven Lorenz Bauer
2020-09-04 11:23 ` [PATCH bpf-next 01/11] btf: Fix BTF_SET_START_GLOBAL macro Lorenz Bauer
2020-09-09 4:04 ` Andrii Nakryiko
2020-09-09 9:51 ` Lorenz Bauer
2020-09-04 11:23 ` [PATCH bpf-next 02/11] btf: add a global set of valid BTF socket ids Lorenz Bauer
2020-09-09 4:12 ` Andrii Nakryiko
2020-09-04 11:23 ` [PATCH bpf-next 03/11] btf: make btf_set_contains take a const pointer Lorenz Bauer
2020-09-09 4:13 ` Andrii Nakryiko
2020-09-04 11:23 ` [PATCH bpf-next 04/11] bpf: check scalar or invalid register in check_helper_mem_access Lorenz Bauer
2020-09-09 4:22 ` Andrii Nakryiko
2020-09-09 10:02 ` Lorenz Bauer
2020-09-04 11:23 ` [PATCH bpf-next 05/11] bpf: allow specifying a set of BTF IDs for helper arguments Lorenz Bauer
2020-09-06 23:04 ` Martin KaFai Lau
2020-09-07 9:15 ` Lorenz Bauer
2020-09-09 4:47 ` Andrii Nakryiko
2020-09-09 5:56 ` Martin KaFai Lau
2020-09-09 10:06 ` Lorenz Bauer
2020-09-09 10:11 ` Lorenz Bauer
2020-09-04 11:23 ` [PATCH bpf-next 06/11] bpf: make reference tracking in check_func_arg generic Lorenz Bauer
2020-09-09 4:50 ` Andrii Nakryiko
2020-09-04 11:23 ` [PATCH bpf-next 07/11] bpf: always check access to PTR_TO_CTX regardless of arg_type Lorenz Bauer
2020-09-04 11:23 ` [PATCH bpf-next 08/11] bpf: set meta->raw_mode for pointers to memory closer to it's use Lorenz Bauer
2020-09-04 11:23 ` Lorenz Bauer [this message]
2020-09-04 11:24 ` [PATCH bpf-next 10/11] bpf: hoist type checking for nullable arg types Lorenz Bauer
2020-09-09 5:07 ` Andrii Nakryiko
2020-09-04 11:24 ` [PATCH bpf-next 11/11] bpf: use a table to drive helper arg type checks Lorenz Bauer
2020-09-09 6:17 ` [PATCH bpf-next 00/11] RFC: Make check_func_arg table driven Martin KaFai Lau
2020-09-09 10:15 ` Lorenz Bauer
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