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/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;
}