Commit c4d0c3b0 authored Feb 14, 2011 by Dan Rosenberg Committed by Alex Elder Feb 21, 2011

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 <drosenberg@vsecurity.com>
Reviewed-by: Eugene Teo <eugeneteo@kernel.org>
Signed-off-by: Alex Elder <aelder@sgi.com>

parent 9681153b

fs/xfs/xfs_fsops.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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;

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