Commit 3f34885c authored by Kulikov Vasiliy's avatar Kulikov Vasiliy Committed by Alex Elder
Browse files

xfs: fix unsigned underflow in xfs_free_eofblocks 



map_len is unsigned. Checking map_len <= 0 is buggy when it should be
below zero. So, check exact expression instead of map_len.

Signed-off-by: default avatarKulikov Vasiliy <segooon@gmail.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent aea1b953

fs/xfs/xfs_vnodeops.c

+2 −2
Original line number Diff line number Diff line
@@ -589,9 +589,9 @@ xfs_free_eofblocks( 
	 */

	end_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)ip->i_size));

	last_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));

	map_len = last_fsb - end_fsb;

	if (map_len <= 0)

	if (last_fsb <= end_fsb)

		return 0;

	map_len = last_fsb - end_fsb;



	nimaps = 1;

	xfs_ilock(ip, XFS_ILOCK_SHARED);