[PATCH] aio syscalls are not checked by lsm

Another case of missing call to security_file_permission: aio functions
(namely, io_submit) does not check credentials with security modules.

Below is the simple patch to the problem.  It seems that it is enough to
check for rights at the request submission time.
Signed-off-by: NKostik Belousov <kostikbel@gmail.com>
Signed-off-by: NChris Wright <chrisw@osdl.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fs/aio.c

@@ -1397,6 +1397,9 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb)
 		if (unlikely(!access_ok(VERIFY_WRITE, kiocb->ki_buf,
 			kiocb->ki_left)))
 			break;
+		ret = security_file_permission(file, MAY_READ);
+		if (unlikely(ret))
+			break;
 		ret = -EINVAL;
 		if (file->f_op->aio_read)
 			kiocb->ki_retry = aio_pread;
@@ -1409,6 +1412,9 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb)
 		if (unlikely(!access_ok(VERIFY_READ, kiocb->ki_buf,
 			kiocb->ki_left)))
 			break;
+		ret = security_file_permission(file, MAY_WRITE);
+		if (unlikely(ret))
+			break;
 		ret = -EINVAL;
 		if (file->f_op->aio_write)
 			kiocb->ki_retry = aio_pwrite;