[PATCH] xfs: linux-2.6: xfs_ioctl: fix information leak to userland

[Vasiliy Kulikov <segooon@xxxxxxxxx>]

al_hreq is copied from userland.  If al_hreq.buflen is not properly aligned then
xfs_attr_list will ignore the last bytes of kbuf.  These bytes are unitialized.
It leads to leaking of contents of kernel stack memory.

Signed-off-by: Vasiliy Kulikov <segooon@xxxxxxxxx>
---
 Compile tested.

 fs/xfs/linux-2.6/xfs_ioctl.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index 2ea238f..ad442d9 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -416,7 +416,7 @@ xfs_attrlist_by_handle(
        if (IS_ERR(dentry))
                return PTR_ERR(dentry);
 
-       kbuf = kmalloc(al_hreq.buflen, GFP_KERNEL);
+       kbuf = kzalloc(al_hreq.buflen, GFP_KERNEL);
        if (!kbuf)
                goto out_dput;
 
-- 
1.7.0.4