nsfs: validate extensible ioctls

[ Upstream commit f8527a29f4619f74bc30a9845ea87abb9a6faa1e ]

Validate extensible ioctls stricter than we do now.

Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

Author: brauner

fs/nsfs.c

@@ -169,9 +169,11 @@ static bool nsfs_ioctl_valid(unsigned int cmd)
 	/* Extensible ioctls require some extra handling. */
 	switch (_IOC_NR(cmd)) {
 	case _IOC_NR(NS_MNT_GET_INFO):
+		return extensible_ioctl_valid(cmd, NS_MNT_GET_INFO, MNT_NS_INFO_SIZE_VER0);
 	case _IOC_NR(NS_MNT_GET_NEXT):
+		return extensible_ioctl_valid(cmd, NS_MNT_GET_NEXT, MNT_NS_INFO_SIZE_VER0);
 	case _IOC_NR(NS_MNT_GET_PREV):
-		return (_IOC_TYPE(cmd) == _IOC_TYPE(cmd));
+		return extensible_ioctl_valid(cmd, NS_MNT_GET_PREV, MNT_NS_INFO_SIZE_VER0);
 	}
 
 	return false;