On Sat, 2010-10-30 at 18:26 +0400, Vasiliy Kulikov wrote:
> 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 <[email protected]>
> ---
> 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;
>
Looks good. I will take this in and will send
it to Linus for 2.6.37. Thanks.
Reviewed-by: Alex Elder <[email protected]>