From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Thu, 23 Jul 2020 06:08:45 +0000 Subject: [PATCH 03/26] bpfilter: reject kernel addresses Message-Id: <20200723060908.50081-4-hch@lst.de> List-Id: References: <20200723060908.50081-1-hch@lst.de> In-Reply-To: <20200723060908.50081-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "David S. Miller" , Jakub Kicinski , Alexei Starovoitov , Daniel Borkmann , Alexey Kuznetsov , Hideaki YOSHIFUJI , Eric Dumazet Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-sctp@vger.kernel.org, linux-hams@vger.kernel.org, linux-bluetooth@vger.kernel.org, bridge@lists.linux-foundation.org, linux-can@vger.kernel.org, dccp@vger.kernel.org, linux-decnet-user@lists.sourceforge.net, linux-wpan@vger.kernel.org, linux-s390@vger.kernel.org, mptcp@lists.01.org, lvs-devel@vger.kernel.org, rds-devel@oss.oracle.com, linux-afs@lists.infradead.org, tipc-discussion@lists.sourceforge.net, linux-x25@vger.kernel.org The bpfilter user mode helper processes the optval address using process_vm_readv. Don't send it kernel addresses fed under set_fs(KERNEL_DS) as that won't work. Signed-off-by: Christoph Hellwig --- net/bpfilter/bpfilter_kern.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c index 78d561f2c54da7..00540457e5f4d3 100644 --- a/net/bpfilter/bpfilter_kern.c +++ b/net/bpfilter/bpfilter_kern.c @@ -70,6 +70,10 @@ static int bpfilter_process_sockopt(struct sock *sk, int optname, .addr = (uintptr_t)optval, .len = optlen, }; + if (uaccess_kernel()) { + pr_err("kernel access not supported\n"); + return -EFAULT; + } return bpfilter_send_req(&req); } -- 2.27.0