From: Roberto Sassu <[email protected]>
Introduce the bpf_verify_umd_signature() kfunc, to verify UMD-parsed
signatures. The parameters and usage are the same as for
bpf_verify_pkcs7_signature().
Signed-off-by: Roberto Sassu <[email protected]>
---
kernel/trace/bpf_trace.c | 69 ++++++++++++++++++++++++++++++++--------
1 file changed, 55 insertions(+), 14 deletions(-)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index e8da032bb6f..c9cae337596 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1271,7 +1271,7 @@ __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
* The key pointer is marked as invalid, to prevent bpf_key_put() from
* attempting to decrement the key reference count on that pointer. The key
* pointer set in such way is currently understood only by
- * verify_pkcs7_signature().
+ * verify_pkcs7_signature() and verify_umd_signature().
*
* Set *id* to one of the values defined in include/linux/verification.h:
* 0 for the primary keyring (immutable keyring of system keys);
@@ -1317,6 +1317,27 @@ __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
}
#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
+static int validate_key(struct bpf_key *trusted_keyring)
+{
+ int ret = 0;
+
+ if (trusted_keyring->has_ref) {
+ /*
+ * Do the permission check deferred in bpf_lookup_user_key().
+ * See bpf_lookup_user_key() for more details.
+ *
+ * A call to key_task_permission() here would be redundant, as
+ * it is already done by keyring_search() called by
+ * find_asymmetric_key().
+ */
+ ret = key_validate(trusted_keyring->key);
+ if (ret < 0)
+ return ret;
+ }
+
+ return ret;
+}
+
/**
* bpf_verify_pkcs7_signature - verify a PKCS#7 signature
* @data_ptr: data to verify
@@ -1334,19 +1355,9 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
{
int ret;
- if (trusted_keyring->has_ref) {
- /*
- * Do the permission check deferred in bpf_lookup_user_key().
- * See bpf_lookup_user_key() for more details.
- *
- * A call to key_task_permission() here would be redundant, as
- * it is already done by keyring_search() called by
- * find_asymmetric_key().
- */
- ret = key_validate(trusted_keyring->key);
- if (ret < 0)
- return ret;
- }
+ ret = validate_key(trusted_keyring);
+ if (ret < 0)
+ return ret;
return verify_pkcs7_signature(data_ptr->data,
bpf_dynptr_get_size(data_ptr),
@@ -1356,6 +1367,35 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
NULL);
}
+
+/**
+ * bpf_verify_umd_signature - Verify a UMD-parsed signature
+ * @data_ptr: Data to verify
+ * @sig_ptr: Signature of the data
+ * @trusted_keyring: Keyring with keys trusted for signature verification
+ *
+ * Verify the UMD-parsed signature *sig_ptr* against the supplied *data_ptr*
+ * with keys in a keyring referenced by *trusted_keyring*.
+ *
+ * Return: 0 on success, a negative value on error.
+ */
+__bpf_kfunc int bpf_verify_umd_signature(struct bpf_dynptr_kern *data_ptr,
+ struct bpf_dynptr_kern *sig_ptr,
+ struct bpf_key *trusted_keyring)
+{
+ int ret;
+
+ ret = validate_key(trusted_keyring);
+ if (ret < 0)
+ return ret;
+
+ return verify_umd_signature(data_ptr->data,
+ bpf_dynptr_get_size(data_ptr),
+ sig_ptr->data, bpf_dynptr_get_size(sig_ptr),
+ trusted_keyring->key,
+ VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
+ NULL);
+}
#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
__diag_pop();
@@ -1366,6 +1406,7 @@ BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_verify_umd_signature, KF_SLEEPABLE)
#endif
BTF_SET8_END(key_sig_kfunc_set)
--
2.25.1
On 4/25/23 10:35 AM, Roberto Sassu wrote:
> From: Roberto Sassu <[email protected]>
>
> Introduce the bpf_verify_umd_signature() kfunc, to verify UMD-parsed
> signatures. The parameters and usage are the same as for
> bpf_verify_pkcs7_signature().
>
> Signed-off-by: Roberto Sassu <[email protected]>
> ---
> kernel/trace/bpf_trace.c | 69 ++++++++++++++++++++++++++++++++--------
> 1 file changed, 55 insertions(+), 14 deletions(-)
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index e8da032bb6f..c9cae337596 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1271,7 +1271,7 @@ __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
> * The key pointer is marked as invalid, to prevent bpf_key_put() from
> * attempting to decrement the key reference count on that pointer. The key
> * pointer set in such way is currently understood only by
> - * verify_pkcs7_signature().
> + * verify_pkcs7_signature() and verify_umd_signature().
> *
> * Set *id* to one of the values defined in include/linux/verification.h:
> * 0 for the primary keyring (immutable keyring of system keys);
> @@ -1317,6 +1317,27 @@ __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
> }
>
> #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
> +static int validate_key(struct bpf_key *trusted_keyring)
> +{
> + int ret = 0;
> +
> + if (trusted_keyring->has_ref) {
> + /*
> + * Do the permission check deferred in bpf_lookup_user_key().
> + * See bpf_lookup_user_key() for more details.
> + *
> + * A call to key_task_permission() here would be redundant, as
> + * it is already done by keyring_search() called by
> + * find_asymmetric_key().
> + */
> + ret = key_validate(trusted_keyring->key);
> + if (ret < 0)
> + return ret;
The above
if (ret < 0)
return ret;
can be removed.
> + }
> +
> + return ret;
> +}
> +
> /**
> * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
> * @data_ptr: data to verify
> @@ -1334,19 +1355,9 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
> {
> int ret;
>
> - if (trusted_keyring->has_ref) {
> - /*
> - * Do the permission check deferred in bpf_lookup_user_key().
> - * See bpf_lookup_user_key() for more details.
> - *
> - * A call to key_task_permission() here would be redundant, as
> - * it is already done by keyring_search() called by
> - * find_asymmetric_key().
> - */
> - ret = key_validate(trusted_keyring->key);
> - if (ret < 0)
> - return ret;
> - }
> + ret = validate_key(trusted_keyring);
> + if (ret < 0)
> + return ret;
>
> return verify_pkcs7_signature(data_ptr->data,
> bpf_dynptr_get_size(data_ptr),
> @@ -1356,6 +1367,35 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
> VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
> NULL);
> }
> +
> +/**
> + * bpf_verify_umd_signature - Verify a UMD-parsed signature
> + * @data_ptr: Data to verify
> + * @sig_ptr: Signature of the data
> + * @trusted_keyring: Keyring with keys trusted for signature verification
> + *
> + * Verify the UMD-parsed signature *sig_ptr* against the supplied *data_ptr*
> + * with keys in a keyring referenced by *trusted_keyring*.
> + *
> + * Return: 0 on success, a negative value on error.
> + */
> +__bpf_kfunc int bpf_verify_umd_signature(struct bpf_dynptr_kern *data_ptr,
> + struct bpf_dynptr_kern *sig_ptr,
> + struct bpf_key *trusted_keyring)
> +{
> + int ret;
> +
> + ret = validate_key(trusted_keyring);
> + if (ret < 0)
> + return ret;
> +
> + return verify_umd_signature(data_ptr->data,
> + bpf_dynptr_get_size(data_ptr),
> + sig_ptr->data, bpf_dynptr_get_size(sig_ptr),
> + trusted_keyring->key,
> + VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
> + NULL);
> +}
> #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
>
> __diag_pop();
> @@ -1366,6 +1406,7 @@ BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
> BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
> #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
> BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
> +BTF_ID_FLAGS(func, bpf_verify_umd_signature, KF_SLEEPABLE)
> #endif
> BTF_SET8_END(key_sig_kfunc_set)
>
On Tue, 2023-04-25 at 14:25 -0700, Yonghong Song wrote:
>
> On 4/25/23 10:35 AM, Roberto Sassu wrote:
> > From: Roberto Sassu <[email protected]>
> >
> > Introduce the bpf_verify_umd_signature() kfunc, to verify UMD-parsed
> > signatures. The parameters and usage are the same as for
> > bpf_verify_pkcs7_signature().
> >
> > Signed-off-by: Roberto Sassu <[email protected]>
> > ---
> > kernel/trace/bpf_trace.c | 69 ++++++++++++++++++++++++++++++++--------
> > 1 file changed, 55 insertions(+), 14 deletions(-)
> >
> > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> > index e8da032bb6f..c9cae337596 100644
> > --- a/kernel/trace/bpf_trace.c
> > +++ b/kernel/trace/bpf_trace.c
> > @@ -1271,7 +1271,7 @@ __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
> > * The key pointer is marked as invalid, to prevent bpf_key_put() from
> > * attempting to decrement the key reference count on that pointer. The key
> > * pointer set in such way is currently understood only by
> > - * verify_pkcs7_signature().
> > + * verify_pkcs7_signature() and verify_umd_signature().
> > *
> > * Set *id* to one of the values defined in include/linux/verification.h:
> > * 0 for the primary keyring (immutable keyring of system keys);
> > @@ -1317,6 +1317,27 @@ __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
> > }
> >
> > #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
> > +static int validate_key(struct bpf_key *trusted_keyring)
> > +{
> > + int ret = 0;
> > +
> > + if (trusted_keyring->has_ref) {
> > + /*
> > + * Do the permission check deferred in bpf_lookup_user_key().
> > + * See bpf_lookup_user_key() for more details.
> > + *
> > + * A call to key_task_permission() here would be redundant, as
> > + * it is already done by keyring_search() called by
> > + * find_asymmetric_key().
> > + */
> > + ret = key_validate(trusted_keyring->key);
> > + if (ret < 0)
> > + return ret;
>
> The above
> if (ret < 0)
> return ret;
> can be removed.
Right, thanks!
Roberto
> > + }
> > +
> > + return ret;
> > +}
> > +
> > /**
> > * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
> > * @data_ptr: data to verify
> > @@ -1334,19 +1355,9 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
> > {
> > int ret;
> >
> > - if (trusted_keyring->has_ref) {
> > - /*
> > - * Do the permission check deferred in bpf_lookup_user_key().
> > - * See bpf_lookup_user_key() for more details.
> > - *
> > - * A call to key_task_permission() here would be redundant, as
> > - * it is already done by keyring_search() called by
> > - * find_asymmetric_key().
> > - */
> > - ret = key_validate(trusted_keyring->key);
> > - if (ret < 0)
> > - return ret;
> > - }
> > + ret = validate_key(trusted_keyring);
> > + if (ret < 0)
> > + return ret;
> >
> > return verify_pkcs7_signature(data_ptr->data,
> > bpf_dynptr_get_size(data_ptr),
> > @@ -1356,6 +1367,35 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
> > VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
> > NULL);
> > }
> > +
> > +/**
> > + * bpf_verify_umd_signature - Verify a UMD-parsed signature
> > + * @data_ptr: Data to verify
> > + * @sig_ptr: Signature of the data
> > + * @trusted_keyring: Keyring with keys trusted for signature verification
> > + *
> > + * Verify the UMD-parsed signature *sig_ptr* against the supplied *data_ptr*
> > + * with keys in a keyring referenced by *trusted_keyring*.
> > + *
> > + * Return: 0 on success, a negative value on error.
> > + */
> > +__bpf_kfunc int bpf_verify_umd_signature(struct bpf_dynptr_kern *data_ptr,
> > + struct bpf_dynptr_kern *sig_ptr,
> > + struct bpf_key *trusted_keyring)
> > +{
> > + int ret;
> > +
> > + ret = validate_key(trusted_keyring);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return verify_umd_signature(data_ptr->data,
> > + bpf_dynptr_get_size(data_ptr),
> > + sig_ptr->data, bpf_dynptr_get_size(sig_ptr),
> > + trusted_keyring->key,
> > + VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
> > + NULL);
> > +}
> > #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
> >
> > __diag_pop();
> > @@ -1366,6 +1406,7 @@ BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
> > BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
> > #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
> > BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
> > +BTF_ID_FLAGS(func, bpf_verify_umd_signature, KF_SLEEPABLE)
> > #endif
> > BTF_SET8_END(key_sig_kfunc_set)
> >