From: Dan Rosenberg <[email protected]> ------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. -------------------
commit 3a3675b7f23f83ca8c67c9c2b6edf707fd28d1ba upstream. The FSGEOMETRY_V1 ioctl (and its compat equivalent) calls out to xfs_fs_geometry() with a version number of 3. This code path does not fill in the logsunit member of the passed xfs_fsop_geom_t, leading to the leaking of four bytes of uninitialized stack data to potentially unprivileged callers. v2 switches to memset() to avoid future issues if structure members change, on suggestion of Dave Chinner. Signed-off-by: Dan Rosenberg <[email protected]> Reviewed-by: Eugene Teo <[email protected]> Signed-off-by: Alex Elder <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- fs/xfs/xfs_fsops.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index 37a6f62..4e7f02b 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -57,6 +57,9 @@ xfs_fs_geometry( xfs_fsop_geom_t *geo, int new_version) { + + memset(geo, 0, sizeof(*geo)); + geo->blocksize = mp->m_sb.sb_blocksize; geo->rtextsize = mp->m_sb.sb_rextsize; geo->agblocks = mp->m_sb.sb_agblocks; -- 1.7.4.4 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
