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Commit 8d5d3fb3 authored by Darrick J. Wong's avatar Darrick J. Wong Committed by Greg Kroah-Hartman
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xfs: fix over-copying of getbmap parameters from userspace 



commit be6324c00c4d1e0e665f03ed1fc18863a88da119 upstream.

In xfs_ioc_getbmap, we should only copy the fields of struct getbmap
from userspace, or else we end up copying random stack contents into the
kernel.  struct getbmap is a strict subset of getbmapx, so a partial
structure copy should work fine.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4c890b8c

fs/xfs/xfs_ioctl.c

+3 −2
Original line number Diff line number Diff line
@@ -1378,10 +1378,11 @@ xfs_ioc_getbmap( 
	unsigned int		cmd,

	void			__user *arg)

{

	struct getbmapx		bmx;

	struct getbmapx		bmx = { 0 };

	int			error;



	if (copy_from_user(&bmx, arg, sizeof(struct getbmapx)))

	/* struct getbmap is a strict subset of struct getbmapx. */

	if (copy_from_user(&bmx, arg, offsetof(struct getbmapx, bmv_iflags)))

		return -EFAULT;



	if (bmx.bmv_count < 2)