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authorDan Rosenberg <drosenberg@vsecurity.com>2011-02-14 13:45:28 +0000
committerPaul Gortmaker <paul.gortmaker@windriver.com>2011-06-26 12:47:19 -0400
commit5658d0e0d4830af95fcde40bc7c6db2dec8ebddf (patch)
tree63db5d2fb2631ae79481d74ed8714d1ef4d909d2
parent11c66be05f49f70a635a6eb63e6cffea520b22c5 (diff)
downloadlinux-rt-5658d0e0d4830af95fcde40bc7c6db2dec8ebddf.tar.gz
xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1
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 <drosenberg@vsecurity.com> Reviewed-by: Eugene Teo <eugeneteo@kernel.org> Signed-off-by: Alex Elder <aelder@sgi.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
-rw-r--r--fs/xfs/xfs_fsops.c3
1 files changed, 3 insertions, 0 deletions
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;