From c4d0c3b097f7584772316ee4d64a09fe0e4ddfca Mon Sep 17 00:00:00 2001 From: Dan Rosenberg Date: Mon, 14 Feb 2011 13:45:28 +0000 Subject: [PATCH] xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1 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 Reviewed-by: Eugene Teo Signed-off-by: Alex Elder --- fs/xfs/xfs_fsops.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index cec89dd5d7d2..85668efb3e3e 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -53,6 +53,9 @@ 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; -- 2.39.5