Commit a5d55070 authored Aug 22, 2013 by Yann Droneaud Committed by Alex Williamson Aug 22, 2013

vfio: use get_unused_fd_flags(0) instead of get_unused_fd()



Macro get_unused_fd() is used to allocate a file descriptor with
default flags. Those default flags (0) can be "unsafe":
O_CLOEXEC must be used by default to not leak file descriptor
across exec().

Instead of macro get_unused_fd(), functions anon_inode_getfd()
or get_unused_fd_flags() should be used with flags given by userspace.
If not possible, flags should be set to O_CLOEXEC to provide userspace
with a default safe behavor.

In a further patch, get_unused_fd() will be removed so that
new code start using anon_inode_getfd() or get_unused_fd_flags()
with correct flags.

This patch replaces calls to get_unused_fd() with equivalent call to
get_unused_fd_flags(0) to preserve current behavor for existing code.

The hard coded flag value (0) should be reviewed on a per-subsystem basis,
and, if possible, set to O_CLOEXEC.

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://lkml.kernel.org/r/cover.1376327678.git.ydroneaud@opteya.com


Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

parent 6cdd9782

drivers/vfio/vfio.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1109,7 +1109,7 @@ static int vfio_group_get_device_fd(struct vfio_group group, char buf)
		* We can't use anon_inode_getfd() because we need to modify
		* the f_mode flags directly to allow more than just ioctls
		*/
		ret = get_unused_fd();
		ret = get_unused_fd_flags(0);
		if (ret < 0) {
		device->ops->release(device->device_data);
		break;