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Diffstat (limited to 'kernel/bpf/btf.c')
-rw-r--r--kernel/bpf/btf.c58
1 files changed, 25 insertions, 33 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 378cef70341c..ee4c82667d65 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -2067,56 +2067,47 @@ static int btf_check_sec_info(struct btf_verifier_env *env,
return 0;
}
-static int btf_parse_hdr(struct btf_verifier_env *env, void __user *btf_data,
- u32 btf_data_size)
+static int btf_parse_hdr(struct btf_verifier_env *env)
{
+ u32 hdr_len, hdr_copy, btf_data_size;
const struct btf_header *hdr;
- u32 hdr_len, hdr_copy;
- /*
- * Minimal part of the "struct btf_header" that
- * contains the hdr_len.
- */
- struct btf_min_header {
- u16 magic;
- u8 version;
- u8 flags;
- u32 hdr_len;
- } __user *min_hdr;
struct btf *btf;
int err;
btf = env->btf;
- min_hdr = btf_data;
+ btf_data_size = btf->data_size;
- if (btf_data_size < sizeof(*min_hdr)) {
+ if (btf_data_size <
+ offsetof(struct btf_header, hdr_len) + sizeof(hdr->hdr_len)) {
btf_verifier_log(env, "hdr_len not found");
return -EINVAL;
}
- if (get_user(hdr_len, &min_hdr->hdr_len))
- return -EFAULT;
-
+ hdr = btf->data;
+ hdr_len = hdr->hdr_len;
if (btf_data_size < hdr_len) {
btf_verifier_log(env, "btf_header not found");
return -EINVAL;
}
- err = bpf_check_uarg_tail_zero(btf_data, sizeof(btf->hdr), hdr_len);
- if (err) {
- if (err == -E2BIG)
- btf_verifier_log(env, "Unsupported btf_header");
- return err;
+ /* Ensure the unsupported header fields are zero */
+ if (hdr_len > sizeof(btf->hdr)) {
+ u8 *expected_zero = btf->data + sizeof(btf->hdr);
+ u8 *end = btf->data + hdr_len;
+
+ for (; expected_zero < end; expected_zero++) {
+ if (*expected_zero) {
+ btf_verifier_log(env, "Unsupported btf_header");
+ return -E2BIG;
+ }
+ }
}
hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr));
- if (copy_from_user(&btf->hdr, btf_data, hdr_copy))
- return -EFAULT;
+ memcpy(&btf->hdr, btf->data, hdr_copy);
hdr = &btf->hdr;
- if (hdr->hdr_len != hdr_len)
- return -EINVAL;
-
btf_verifier_log_hdr(env, btf_data_size);
if (hdr->magic != BTF_MAGIC) {
@@ -2186,10 +2177,6 @@ static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size,
}
env->btf = btf;
- err = btf_parse_hdr(env, btf_data, btf_data_size);
- if (err)
- goto errout;
-
data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN);
if (!data) {
err = -ENOMEM;
@@ -2198,13 +2185,18 @@ static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size,
btf->data = data;
btf->data_size = btf_data_size;
- btf->nohdr_data = btf->data + btf->hdr.hdr_len;
if (copy_from_user(data, btf_data, btf_data_size)) {
err = -EFAULT;
goto errout;
}
+ err = btf_parse_hdr(env);
+ if (err)
+ goto errout;
+
+ btf->nohdr_data = btf->data + btf->hdr.hdr_len;
+
err = btf_parse_str_sec(env);
if (err)
goto errout;