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Diffstat (limited to 'kernel/bpf/btf.c')
-rw-r--r--kernel/bpf/btf.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index ee4c82667d65..4da543d6bea2 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -5,6 +5,7 @@
#include <uapi/linux/types.h>
#include <linux/seq_file.h>
#include <linux/compiler.h>
+#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/anon_inodes.h>
@@ -426,6 +427,30 @@ static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
offset < btf->hdr.str_len;
}
+/* Only C-style identifier is permitted. This can be relaxed if
+ * necessary.
+ */
+static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
+{
+ /* offset must be valid */
+ const char *src = &btf->strings[offset];
+ const char *src_limit;
+
+ if (!isalpha(*src) && *src != '_')
+ return false;
+
+ /* set a limit on identifier length */
+ src_limit = src + KSYM_NAME_LEN;
+ src++;
+ while (*src && src < src_limit) {
+ if (!isalnum(*src) && *src != '_')
+ return false;
+ src++;
+ }
+
+ return !*src;
+}
+
static const char *btf_name_by_offset(const struct btf *btf, u32 offset)
{
if (!offset)
@@ -1143,6 +1168,22 @@ static int btf_ref_type_check_meta(struct btf_verifier_env *env,
return -EINVAL;
}
+ /* typedef type must have a valid name, and other ref types,
+ * volatile, const, restrict, should have a null name.
+ */
+ if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) {
+ if (!t->name_off ||
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+ } else {
+ if (t->name_off) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+ }
+
btf_verifier_log_type(env, t, NULL);
return 0;
@@ -1300,6 +1341,13 @@ static s32 btf_fwd_check_meta(struct btf_verifier_env *env,
return -EINVAL;
}
+ /* fwd type must have a valid name */
+ if (!t->name_off ||
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
btf_verifier_log_type(env, t, NULL);
return 0;
@@ -1356,6 +1404,12 @@ static s32 btf_array_check_meta(struct btf_verifier_env *env,
return -EINVAL;
}
+ /* array type should not have a name */
+ if (t->name_off) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
if (btf_type_vlen(t)) {
btf_verifier_log_type(env, t, "vlen != 0");
return -EINVAL;
@@ -1532,6 +1586,13 @@ static s32 btf_struct_check_meta(struct btf_verifier_env *env,
return -EINVAL;
}
+ /* struct type either no name or a valid one */
+ if (t->name_off &&
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
btf_verifier_log_type(env, t, NULL);
last_offset = 0;
@@ -1543,6 +1604,12 @@ static s32 btf_struct_check_meta(struct btf_verifier_env *env,
return -EINVAL;
}
+ /* struct member either no name or a valid one */
+ if (member->name_off &&
+ !btf_name_valid_identifier(btf, member->name_off)) {
+ btf_verifier_log_member(env, t, member, "Invalid name");
+ return -EINVAL;
+ }
/* A member cannot be in type void */
if (!member->type || !BTF_TYPE_ID_VALID(member->type)) {
btf_verifier_log_member(env, t, member,
@@ -1730,6 +1797,13 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env,
return -EINVAL;
}
+ /* enum type either no name or a valid one */
+ if (t->name_off &&
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
btf_verifier_log_type(env, t, NULL);
for (i = 0; i < nr_enums; i++) {
@@ -1739,6 +1813,14 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env,
return -EINVAL;
}
+ /* enum member must have a valid name */
+ if (!enums[i].name_off ||
+ !btf_name_valid_identifier(btf, enums[i].name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+
btf_verifier_log(env, "\t%s val=%d\n",
btf_name_by_offset(btf, enums[i].name_off),
enums[i].val);