Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/security/keys/big_key.c b/security/keys/big_key.c
index 001abe5..82008f9 100644
--- a/security/keys/big_key.c
+++ b/security/keys/big_key.c
@@ -352,7 +352,7 @@
  * read the key data
  * - the key's semaphore is read-locked
  */
-long big_key_read(const struct key *key, char __user *buffer, size_t buflen)
+long big_key_read(const struct key *key, char *buffer, size_t buflen)
 {
 	size_t datalen = (size_t)key->payload.data[big_key_len];
 	long ret;
@@ -391,9 +391,8 @@
 
 		ret = datalen;
 
-		/* copy decrypted data to user */
-		if (copy_to_user(buffer, buf->virt, datalen) != 0)
-			ret = -EFAULT;
+		/* copy out decrypted data */
+		memcpy(buffer, buf->virt, datalen);
 
 err_fput:
 		fput(file);
@@ -401,9 +400,7 @@
 		big_key_free_buffer(buf);
 	} else {
 		ret = datalen;
-		if (copy_to_user(buffer, key->payload.data[big_key_data],
-				 datalen) != 0)
-			ret = -EFAULT;
+		memcpy(buffer, key->payload.data[big_key_data], datalen);
 	}
 
 	return ret;
diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index 60720f5..f6797ba 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -902,14 +902,14 @@
 }
 
 /*
- * encrypted_read - format and copy the encrypted data to userspace
+ * encrypted_read - format and copy out the encrypted data
  *
  * The resulting datablob format is:
  * <master-key name> <decrypted data length> <encrypted iv> <encrypted data>
  *
  * On success, return to userspace the encrypted key datablob size.
  */
-static long encrypted_read(const struct key *key, char __user *buffer,
+static long encrypted_read(const struct key *key, char *buffer,
 			   size_t buflen)
 {
 	struct encrypted_key_payload *epayload;
@@ -957,8 +957,7 @@
 	key_put(mkey);
 	memzero_explicit(derived_key, sizeof(derived_key));
 
-	if (copy_to_user(buffer, ascii_buf, asciiblob_len) != 0)
-		ret = -EFAULT;
+	memcpy(buffer, ascii_buf, asciiblob_len);
 	kzfree(ascii_buf);
 
 	return asciiblob_len;
diff --git a/security/keys/internal.h b/security/keys/internal.h
index c039373..1ca8bfa 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -16,6 +16,8 @@
 #include <linux/keyctl.h>
 #include <linux/refcount.h>
 #include <linux/compat.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
 
 struct iovec;
 
@@ -348,5 +350,4 @@
 #define key_check(key) do {} while(0)
 
 #endif
-
 #endif /* _INTERNAL_H */
diff --git a/security/keys/key.c b/security/keys/key.c
index 764f4c5..623fcb4 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -302,6 +302,8 @@
 		key->flags |= 1 << KEY_FLAG_BUILTIN;
 	if (flags & KEY_ALLOC_UID_KEYRING)
 		key->flags |= 1 << KEY_FLAG_UID_KEYRING;
+	if (flags & KEY_ALLOC_SET_KEEP)
+		key->flags |= 1 << KEY_FLAG_KEEP;
 
 #ifdef KEY_DEBUGGING
 	key->magic = KEY_DEBUG_MAGIC;
@@ -381,7 +383,7 @@
 		spin_lock(&key->user->lock);
 
 		if (delta > 0 &&
-		    (key->user->qnbytes + delta >= maxbytes ||
+		    (key->user->qnbytes + delta > maxbytes ||
 		     key->user->qnbytes + delta < key->user->qnbytes)) {
 			ret = -EDQUOT;
 		}
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 9b898c9..edde63a 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -142,10 +142,7 @@
 
 	key_ref_put(keyring_ref);
  error3:
-	if (payload) {
-		memzero_explicit(payload, plen);
-		kvfree(payload);
-	}
+	kvfree_sensitive(payload, plen);
  error2:
 	kfree(description);
  error:
@@ -339,7 +336,7 @@
 	payload = NULL;
 	if (plen) {
 		ret = -ENOMEM;
-		payload = kmalloc(plen, GFP_KERNEL);
+		payload = kvmalloc(plen, GFP_KERNEL);
 		if (!payload)
 			goto error;
 
@@ -360,7 +357,7 @@
 
 	key_ref_put(key_ref);
 error2:
-	kzfree(payload);
+	kvfree_sensitive(payload, plen);
 error:
 	return ret;
 }
@@ -798,6 +795,21 @@
 }
 
 /*
+ * Call the read method
+ */
+static long __keyctl_read_key(struct key *key, char *buffer, size_t buflen)
+{
+	long ret;
+
+	down_read(&key->sem);
+	ret = key_validate(key);
+	if (ret == 0)
+		ret = key->type->read(key, buffer, buflen);
+	up_read(&key->sem);
+	return ret;
+}
+
+/*
  * Read a key's payload.
  *
  * The key must either grant the caller Read permission, or it must grant the
@@ -812,26 +824,28 @@
 	struct key *key;
 	key_ref_t key_ref;
 	long ret;
+	char *key_data = NULL;
+	size_t key_data_len;
 
 	/* find the key first */
 	key_ref = lookup_user_key(keyid, 0, 0);
 	if (IS_ERR(key_ref)) {
 		ret = -ENOKEY;
-		goto error;
+		goto out;
 	}
 
 	key = key_ref_to_ptr(key_ref);
 
 	ret = key_read_state(key);
 	if (ret < 0)
-		goto error2; /* Negatively instantiated */
+		goto key_put_out; /* Negatively instantiated */
 
 	/* see if we can read it directly */
 	ret = key_permission(key_ref, KEY_NEED_READ);
 	if (ret == 0)
 		goto can_read_key;
 	if (ret != -EACCES)
-		goto error2;
+		goto key_put_out;
 
 	/* we can't; see if it's searchable from this process's keyrings
 	 * - we automatically take account of the fact that it may be
@@ -839,26 +853,78 @@
 	 */
 	if (!is_key_possessed(key_ref)) {
 		ret = -EACCES;
-		goto error2;
+		goto key_put_out;
 	}
 
 	/* the key is probably readable - now try to read it */
 can_read_key:
-	ret = -EOPNOTSUPP;
-	if (key->type->read) {
-		/* Read the data with the semaphore held (since we might sleep)
-		 * to protect against the key being updated or revoked.
-		 */
-		down_read(&key->sem);
-		ret = key_validate(key);
-		if (ret == 0)
-			ret = key->type->read(key, buffer, buflen);
-		up_read(&key->sem);
+	if (!key->type->read) {
+		ret = -EOPNOTSUPP;
+		goto key_put_out;
 	}
 
-error2:
+	if (!buffer || !buflen) {
+		/* Get the key length from the read method */
+		ret = __keyctl_read_key(key, NULL, 0);
+		goto key_put_out;
+	}
+
+	/*
+	 * Read the data with the semaphore held (since we might sleep)
+	 * to protect against the key being updated or revoked.
+	 *
+	 * Allocating a temporary buffer to hold the keys before
+	 * transferring them to user buffer to avoid potential
+	 * deadlock involving page fault and mmap_sem.
+	 *
+	 * key_data_len = (buflen <= PAGE_SIZE)
+	 *		? buflen : actual length of key data
+	 *
+	 * This prevents allocating arbitrary large buffer which can
+	 * be much larger than the actual key length. In the latter case,
+	 * at least 2 passes of this loop is required.
+	 */
+	key_data_len = (buflen <= PAGE_SIZE) ? buflen : 0;
+	for (;;) {
+		if (key_data_len) {
+			key_data = kvmalloc(key_data_len, GFP_KERNEL);
+			if (!key_data) {
+				ret = -ENOMEM;
+				goto key_put_out;
+			}
+		}
+
+		ret = __keyctl_read_key(key, key_data, key_data_len);
+
+		/*
+		 * Read methods will just return the required length without
+		 * any copying if the provided length isn't large enough.
+		 */
+		if (ret <= 0 || ret > buflen)
+			break;
+
+		/*
+		 * The key may change (unlikely) in between 2 consecutive
+		 * __keyctl_read_key() calls. In this case, we reallocate
+		 * a larger buffer and redo the key read when
+		 * key_data_len < ret <= buflen.
+		 */
+		if (ret > key_data_len) {
+			if (unlikely(key_data))
+				kvfree_sensitive(key_data, key_data_len);
+			key_data_len = ret;
+			continue;	/* Allocate buffer */
+		}
+
+		if (copy_to_user(buffer, key_data, ret))
+			ret = -EFAULT;
+		break;
+	}
+	kvfree_sensitive(key_data, key_data_len);
+
+key_put_out:
 	key_put(key);
-error:
+out:
 	return ret;
 }
 
@@ -937,8 +1003,8 @@
 				key_quota_root_maxbytes : key_quota_maxbytes;
 
 			spin_lock(&newowner->lock);
-			if (newowner->qnkeys + 1 >= maxkeys ||
-			    newowner->qnbytes + key->quotalen >= maxbytes ||
+			if (newowner->qnkeys + 1 > maxkeys ||
+			    newowner->qnbytes + key->quotalen > maxbytes ||
 			    newowner->qnbytes + key->quotalen <
 			    newowner->qnbytes)
 				goto quota_overrun;
@@ -1156,10 +1222,7 @@
 		keyctl_change_reqkey_auth(NULL);
 
 error2:
-	if (payload) {
-		memzero_explicit(payload, plen);
-		kvfree(payload);
-	}
+	kvfree_sensitive(payload, plen);
 error:
 	return ret;
 }
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index febf36c..5ca620d 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -459,7 +459,6 @@
 {
 	struct keyring_read_iterator_context *ctx = data;
 	const struct key *key = keyring_ptr_to_key(object);
-	int ret;
 
 	kenter("{%s,%d},,{%zu/%zu}",
 	       key->type->name, key->serial, ctx->count, ctx->buflen);
@@ -467,10 +466,7 @@
 	if (ctx->count >= ctx->buflen)
 		return 1;
 
-	ret = put_user(key->serial, ctx->buffer);
-	if (ret < 0)
-		return ret;
-	ctx->buffer++;
+	*ctx->buffer++ = key->serial;
 	ctx->count += sizeof(key->serial);
 	return 0;
 }
diff --git a/security/keys/proc.c b/security/keys/proc.c
index 415f3f1..d0cde66 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -139,6 +139,8 @@
 	n = key_serial_next(p, v);
 	if (n)
 		*_pos = key_node_serial(n);
+	else
+		(*_pos)++;
 	return n;
 }
 
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index ecba39c..41e9735 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -22,7 +22,7 @@
 static void request_key_auth_describe(const struct key *, struct seq_file *);
 static void request_key_auth_revoke(struct key *);
 static void request_key_auth_destroy(struct key *);
-static long request_key_auth_read(const struct key *, char __user *, size_t);
+static long request_key_auth_read(const struct key *, char *, size_t);
 
 /*
  * The request-key authorisation key type definition.
@@ -80,7 +80,7 @@
  * - the key's semaphore is read-locked
  */
 static long request_key_auth_read(const struct key *key,
-				  char __user *buffer, size_t buflen)
+				  char *buffer, size_t buflen)
 {
 	struct request_key_auth *rka = dereference_key_locked(key);
 	size_t datalen;
@@ -97,8 +97,7 @@
 		if (buflen > datalen)
 			buflen = datalen;
 
-		if (copy_to_user(buffer, rka->callout_info, buflen) != 0)
-			ret = -EFAULT;
+		memcpy(buffer, rka->callout_info, buflen);
 	}
 
 	return ret;
diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index 1fbd778..92a14ab 100644
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -805,7 +805,7 @@
 		case Opt_migratable:
 			if (*args[0].from == '0')
 				pay->migratable = 0;
-			else
+			else if (*args[0].from != '1')
 				return -EINVAL;
 			break;
 		case Opt_pcrlock:
@@ -1144,11 +1144,10 @@
  * trusted_read - copy the sealed blob data to userspace in hex.
  * On success, return to userspace the trusted key datablob size.
  */
-static long trusted_read(const struct key *key, char __user *buffer,
+static long trusted_read(const struct key *key, char *buffer,
 			 size_t buflen)
 {
 	const struct trusted_key_payload *p;
-	char *ascii_buf;
 	char *bufp;
 	int i;
 
@@ -1157,18 +1156,9 @@
 		return -EINVAL;
 
 	if (buffer && buflen >= 2 * p->blob_len) {
-		ascii_buf = kmalloc_array(2, p->blob_len, GFP_KERNEL);
-		if (!ascii_buf)
-			return -ENOMEM;
-
-		bufp = ascii_buf;
+		bufp = buffer;
 		for (i = 0; i < p->blob_len; i++)
 			bufp = hex_byte_pack(bufp, p->blob[i]);
-		if (copy_to_user(buffer, ascii_buf, 2 * p->blob_len) != 0) {
-			kzfree(ascii_buf);
-			return -EFAULT;
-		}
-		kzfree(ascii_buf);
 	}
 	return 2 * p->blob_len;
 }
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index 6f12de4..07d4287 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -168,7 +168,7 @@
  * read the key data
  * - the key's semaphore is read-locked
  */
-long user_read(const struct key *key, char __user *buffer, size_t buflen)
+long user_read(const struct key *key, char *buffer, size_t buflen)
 {
 	const struct user_key_payload *upayload;
 	long ret;
@@ -181,8 +181,7 @@
 		if (buflen > upayload->datalen)
 			buflen = upayload->datalen;
 
-		if (copy_to_user(buffer, upayload->data, buflen) != 0)
-			ret = -EFAULT;
+		memcpy(buffer, upayload->data, buflen);
 	}
 
 	return ret;