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

From: Vasiliy Kulikov
Date: Sat Oct 30 2010 - 10:26:28 EST


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

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