xfs: fix kernel memory exposure problems

commit bf9216f922612d2db7666aae01e65064da2ffb3a upstream.

Fix a memory exposure problems in inumbers where we allocate an array of
structures with holes, fail to zero the holes, then blindly copy the
kernel memory contents (junk and all) into userspace.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index 66e8817..d8a77db 100644 (file)
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -585,7 +585,7 @@ xfs_inumbers(
                return error;
 
        bcount = MIN(left, (int)(PAGE_SIZE / sizeof(*buffer)));
-       buffer = kmem_alloc(bcount * sizeof(*buffer), KM_SLEEP);
+       buffer = kmem_zalloc(bcount * sizeof(*buffer), KM_SLEEP);
        do {
                struct xfs_inobt_rec_incore     r;
                int                             stat;