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authorDan Rosenberg <drosenberg@vsecurity.com>2011-02-14 14:45:28 +0100
committerAlex Elder <aelder@sgi.com>2011-02-22 02:55:47 +0100
commitc4d0c3b097f7584772316ee4d64a09fe0e4ddfca (patch)
tree46ca0bf816086d7ac55ba0191e44119e14ef0d70
parentxfs: add lockdep annotations for the rt inodes (diff)
downloadlinux-c4d0c3b097f7584772316ee4d64a09fe0e4ddfca.tar.xz
linux-c4d0c3b097f7584772316ee4d64a09fe0e4ddfca.zip
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 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;