[PATCH v2] xfs: overflow in xfs_iomap_eof_align_last_fsb

Peter Watkins
2014-12-01T22:45:39Z

If extsize is set and new_last_fsb is larger than 32 bits, the
roundup to extsize will overflow the align variable. Instead,
combine alignments by rounding stripe size up to extsize.

Signed-off-by: Peter Watkins <treestem@gmail.com>
Reviewed-by: Nathaniel W. Turner <nate@houseofnate.net>
---
fs/xfs/xfs_iomap.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index afcf3c9..3fad071 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -52,7 +52,6 @@ xfs_iomap_eof_align_last_fsb(
xfs_extlen_t extsize,
xfs_fileoff_t *last_fsb)
{
- xfs_fileoff_t new_last_fsb = 0;
xfs_extlen_t align = 0;
int eof, error;

@@ -70,8 +69,8 @@ xfs_iomap_eof_align_last_fsb(
else if (mp->m_dalign)
align = mp->m_dalign;

- if (align && XFS_ISIZE(ip) >= XFS_FSB_TO_B(mp, align))
- new_last_fsb = roundup_64(*last_fsb, align);
+ if (align && XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, align))
+ align = 0;
}

/*
@@ -79,14 +78,14 @@ xfs_iomap_eof_align_last_fsb(
* (when file on a real-time subvolume or has di_extsize hint).
*/
if (extsize) {
- if (new_last_fsb)
- align = roundup_64(new_last_fsb, extsize);
+ if (align)
+ align = roundup_64(align, extsize);
else
align = extsize;
- new_last_fsb = roundup_64(*last_fsb, align);
}

- if (new_last_fsb) {
+ if (align) {
+ xfs_fileoff_t new_last_fsb = roundup_64(*last_fsb, align);
error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
if (error)
return error;
--
1.7.9.5