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authorDan Rosenberg <drosenberg@vsecurity.com>2011-02-14 13:45:28 (GMT)
committerAlex Elder <aelder@sgi.com>2011-02-22 01:55:47 (GMT)
commitc4d0c3b097f7584772316ee4d64a09fe0e4ddfca (patch)
tree46ca0bf816086d7ac55ba0191e44119e14ef0d70
parent9681153b460006923bb1e9d39b05b80ec09d6b4e (diff)
downloadlinux-c4d0c3b097f7584772316ee4d64a09fe0e4ddfca.tar.xz
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>
-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 cec89dd..85668ef 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;