diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 9b898c969558..564a4d187329 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c

@@ -846,14 +846,36 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
 can_read_key:
 	ret = -EOPNOTSUPP;
 	if (key->type->read) {
-		/* Read the data with the semaphore held (since we might sleep)
+		/*
+		 * 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.
 		 */
+		char *tmpbuf = kmalloc(buflen, GFP_KERNEL);