Merge tag 'char-misc-5.13-rc1-round2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver fixes from Greg KH:
 "Here are two char/misc fixes for 5.13-rc1 to resolve reported issues.

  The first is a bugfix for the nitro_enclaves driver that fixed some
  important problems. The second was a dyndbg bugfix that resolved some
  reported problems in dynamic debugging control.

  Both have been in linux-next for a while with no reported issues"

* tag 'char-misc-5.13-rc1-round2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  dyndbg: fix parsing file query without a line-range suffix
  nitro_enclaves: Fix stale file descriptors on failed usercopy

1 files changed, 17 insertions, 26 deletions

diff --git a/drivers/virt/nitro_enclaves/ne_misc_dev.c b/drivers/virt/nitro_enclaves/ne_misc_dev.c
index f1964ea4b826..e21e1e86ad15 100644
--- a/drivers/virt/nitro_enclaves/ne_misc_dev.c
+++ b/drivers/virt/nitro_enclaves/ne_misc_dev.c
@@ -1524,7 +1524,8 @@ static const struct file_operations ne_enclave_fops = {
  *			  enclave file descriptor to be further used for enclave
  *			  resources handling e.g. memory regions and CPUs.
  * @ne_pci_dev :	Private data associated with the PCI device.
- * @slot_uid:		Generated unique slot id associated with an enclave.
+ * @slot_uid:		User pointer to store the generated unique slot id
+ *			associated with an enclave to.
  *
  * Context: Process context. This function is called with the ne_pci_dev enclave
  *	    mutex held.
@@ -1532,7 +1533,7 @@ static const struct file_operations ne_enclave_fops = {
  * * Enclave fd on success.
  * * Negative return value on failure.
  */
-static int ne_create_vm_ioctl(struct ne_pci_dev *ne_pci_dev, u64 *slot_uid)
+static int ne_create_vm_ioctl(struct ne_pci_dev *ne_pci_dev, u64 __user *slot_uid)
 {
 	struct ne_pci_dev_cmd_reply cmd_reply = {};
 	int enclave_fd = -1;
@@ -1634,7 +1635,18 @@ static int ne_create_vm_ioctl(struct ne_pci_dev *ne_pci_dev, u64 *slot_uid)
 
 	list_add(&ne_enclave->enclave_list_entry, &ne_pci_dev->enclaves_list);
 
-	*slot_uid = ne_enclave->slot_uid;
+	if (copy_to_user(slot_uid, &ne_enclave->slot_uid, sizeof(ne_enclave->slot_uid))) {
+		/*
+		 * As we're holding the only reference to 'enclave_file', fput()
+		 * will call ne_enclave_release() which will do a proper cleanup
+		 * of all so far allocated resources, leaving only the unused fd
+		 * for us to free.
+		 */
+		fput(enclave_file);
+		put_unused_fd(enclave_fd);
+
+		return -EFAULT;
+	}
 
 	fd_install(enclave_fd, enclave_file);
 
@@ -1671,34 +1683,13 @@ static long ne_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	switch (cmd) {
 	case NE_CREATE_VM: {
 		int enclave_fd = -1;
-		struct file *enclave_file = NULL;
 		struct ne_pci_dev *ne_pci_dev = ne_devs.ne_pci_dev;
-		int rc = -EINVAL;
-		u64 slot_uid = 0;
+		u64 __user *slot_uid = (void __user *)arg;
 
 		mutex_lock(&ne_pci_dev->enclaves_list_mutex);
-
-		enclave_fd = ne_create_vm_ioctl(ne_pci_dev, &slot_uid);
-		if (enclave_fd < 0) {
-			rc = enclave_fd;
-
-			mutex_unlock(&ne_pci_dev->enclaves_list_mutex);
-
-			return rc;
-		}
-
+		enclave_fd = ne_create_vm_ioctl(ne_pci_dev, slot_uid);
 		mutex_unlock(&ne_pci_dev->enclaves_list_mutex);
 
-		if (copy_to_user((void __user *)arg, &slot_uid, sizeof(slot_uid))) {
-			enclave_file = fget(enclave_fd);
-			/* Decrement file refs to have release() called. */
-			fput(enclave_file);
-			fput(enclave_file);
-			put_unused_fd(enclave_fd);
-
-			return -EFAULT;
-		}
-
 		return enclave_fd;
 	}