From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: bpf@vger.kernel.org
Cc: "Alexei Starovoitov" <ast@kernel.org>,
"Andrii Nakryiko" <andrii@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Toke Høiland-Jørgensen" <toke@redhat.com>,
"Jesper Dangaard Brouer" <brouer@redhat.com>
Subject: [PATCH bpf-next v4 02/13] bpf: Move check_ptr_off_reg before check_map_access
Date: Sat, 9 Apr 2022 15:02:52 +0530 [thread overview]
Message-ID: <20220409093303.499196-3-memxor@gmail.com> (raw)
In-Reply-To: <20220409093303.499196-1-memxor@gmail.com>
Some functions in next patch want to use this function, and those
functions will be called by check_map_access, hence move it before
check_map_access.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
kernel/bpf/verifier.c | 76 +++++++++++++++++++++----------------------
1 file changed, 38 insertions(+), 38 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 9c1a02b82ecd..71827d14724a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3469,6 +3469,44 @@ static int check_mem_region_access(struct bpf_verifier_env *env, u32 regno,
return 0;
}
+static int __check_ptr_off_reg(struct bpf_verifier_env *env,
+ const struct bpf_reg_state *reg, int regno,
+ bool fixed_off_ok)
+{
+ /* Access to this pointer-typed register or passing it to a helper
+ * is only allowed in its original, unmodified form.
+ */
+
+ if (reg->off < 0) {
+ verbose(env, "negative offset %s ptr R%d off=%d disallowed\n",
+ reg_type_str(env, reg->type), regno, reg->off);
+ return -EACCES;
+ }
+
+ if (!fixed_off_ok && reg->off) {
+ verbose(env, "dereference of modified %s ptr R%d off=%d disallowed\n",
+ reg_type_str(env, reg->type), regno, reg->off);
+ return -EACCES;
+ }
+
+ if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+ char tn_buf[48];
+
+ tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+ verbose(env, "variable %s access var_off=%s disallowed\n",
+ reg_type_str(env, reg->type), tn_buf);
+ return -EACCES;
+ }
+
+ return 0;
+}
+
+int check_ptr_off_reg(struct bpf_verifier_env *env,
+ const struct bpf_reg_state *reg, int regno)
+{
+ return __check_ptr_off_reg(env, reg, regno, false);
+}
+
/* check read/write into a map element with possible variable offset */
static int check_map_access(struct bpf_verifier_env *env, u32 regno,
int off, int size, bool zero_size_allowed)
@@ -3980,44 +4018,6 @@ static int get_callee_stack_depth(struct bpf_verifier_env *env,
}
#endif
-static int __check_ptr_off_reg(struct bpf_verifier_env *env,
- const struct bpf_reg_state *reg, int regno,
- bool fixed_off_ok)
-{
- /* Access to this pointer-typed register or passing it to a helper
- * is only allowed in its original, unmodified form.
- */
-
- if (reg->off < 0) {
- verbose(env, "negative offset %s ptr R%d off=%d disallowed\n",
- reg_type_str(env, reg->type), regno, reg->off);
- return -EACCES;
- }
-
- if (!fixed_off_ok && reg->off) {
- verbose(env, "dereference of modified %s ptr R%d off=%d disallowed\n",
- reg_type_str(env, reg->type), regno, reg->off);
- return -EACCES;
- }
-
- if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
- char tn_buf[48];
-
- tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
- verbose(env, "variable %s access var_off=%s disallowed\n",
- reg_type_str(env, reg->type), tn_buf);
- return -EACCES;
- }
-
- return 0;
-}
-
-int check_ptr_off_reg(struct bpf_verifier_env *env,
- const struct bpf_reg_state *reg, int regno)
-{
- return __check_ptr_off_reg(env, reg, regno, false);
-}
-
static int __check_buffer_access(struct bpf_verifier_env *env,
const char *buf_info,
const struct bpf_reg_state *reg,
--
2.35.1
next prev parent reply other threads:[~2022-04-09 9:32 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-09 9:32 [PATCH bpf-next v4 00/13] Introduce typed pointer support in BPF maps Kumar Kartikeya Dwivedi
2022-04-09 9:32 ` [PATCH bpf-next v4 01/13] bpf: Make btf_find_field more generic Kumar Kartikeya Dwivedi
2022-04-11 20:20 ` Joanne Koong
2022-04-12 19:48 ` Kumar Kartikeya Dwivedi
2022-04-09 9:32 ` Kumar Kartikeya Dwivedi [this message]
2022-04-11 20:28 ` [PATCH bpf-next v4 02/13] bpf: Move check_ptr_off_reg before check_map_access Joanne Koong
2022-04-09 9:32 ` [PATCH bpf-next v4 03/13] bpf: Allow storing unreferenced kptr in map Kumar Kartikeya Dwivedi
2022-04-12 0:32 ` Joanne Koong
2022-04-12 19:16 ` Kumar Kartikeya Dwivedi
2022-04-12 23:56 ` Joanne Koong
2022-04-13 5:50 ` Kumar Kartikeya Dwivedi
2022-04-13 5:41 ` kernel test robot
2022-04-09 9:32 ` [PATCH bpf-next v4 04/13] bpf: Tag argument to be released in bpf_func_proto Kumar Kartikeya Dwivedi
2022-04-12 18:16 ` Joanne Koong
2022-04-12 20:11 ` Kumar Kartikeya Dwivedi
2022-04-13 18:33 ` Joanne Koong
2022-04-13 18:39 ` Joanne Koong
2022-04-09 9:32 ` [PATCH bpf-next v4 05/13] bpf: Allow storing referenced kptr in map Kumar Kartikeya Dwivedi
2022-04-12 23:05 ` Joanne Koong
2022-04-13 5:36 ` Kumar Kartikeya Dwivedi
2022-04-13 5:54 ` Kumar Kartikeya Dwivedi
2022-04-09 9:32 ` [PATCH bpf-next v4 06/13] bpf: Prevent escaping of kptr loaded from maps Kumar Kartikeya Dwivedi
2022-04-09 9:32 ` [PATCH bpf-next v4 07/13] bpf: Adapt copy_map_value for multiple offset case Kumar Kartikeya Dwivedi
2022-04-09 9:32 ` [PATCH bpf-next v4 08/13] bpf: Populate pairs of btf_id and destructor kfunc in btf Kumar Kartikeya Dwivedi
2022-04-09 9:32 ` [PATCH bpf-next v4 09/13] bpf: Wire up freeing of referenced kptr Kumar Kartikeya Dwivedi
2022-04-09 9:33 ` [PATCH bpf-next v4 10/13] bpf: Teach verifier about kptr_get kfunc helpers Kumar Kartikeya Dwivedi
2022-04-09 9:33 ` [PATCH bpf-next v4 11/13] libbpf: Add kptr type tag macros to bpf_helpers.h Kumar Kartikeya Dwivedi
2022-04-09 9:33 ` [PATCH bpf-next v4 12/13] selftests/bpf: Add C tests for kptr Kumar Kartikeya Dwivedi
2022-04-09 9:33 ` [PATCH bpf-next v4 13/13] selftests/bpf: Add verifier " Kumar Kartikeya Dwivedi
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