From f3373d71e3cbda31c253a8be1956de17ad089bb6 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 commit c4d0c3b097f7584772316ee4d64a09fe0e4ddfca 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 Signed-off-by: Andi Kleen Reviewed-by: Eugene Teo Signed-off-by: Alex Elder Signed-off-by: Greg Kroah-Hartman --- 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 37a6f62c57b6..4e7f02b22d1d 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; -- 2.39.5