This is a note to let you know that I've just added the patch titled
tap: free skb if flags error
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: tap-free-skb-if-flags-error.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Thu Dec 14 11:45:40 CET 2017
From: Wei Xu wexu@redhat.com Date: Fri, 1 Dec 2017 05:10:38 -0500 Subject: tap: free skb if flags error
From: Wei Xu wexu@redhat.com
[ Upstream commit 61d78537843e676e7f56ac6db333db0c0529b892 ]
tap_recvmsg() supports accepting skb by msg_control after commit 3b4ba04acca8 ("tap: support receiving skb from msg_control"), the skb if presented should be freed within the function, otherwise it would be leaked.
Signed-off-by: Wei Xu wexu@redhat.com Reported-by: Matthew Rosato mjrosato@linux.vnet.ibm.com Acked-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/tap.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
--- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -829,8 +829,11 @@ static ssize_t tap_do_read(struct tap_qu DEFINE_WAIT(wait); ssize_t ret = 0;
- if (!iov_iter_count(to)) + if (!iov_iter_count(to)) { + if (skb) + kfree_skb(skb); return 0; + }
if (skb) goto put; @@ -1154,11 +1157,14 @@ static int tap_recvmsg(struct socket *so size_t total_len, int flags) { struct tap_queue *q = container_of(sock, struct tap_queue, sock); + struct sk_buff *skb = m->msg_control; int ret; - if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) + if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) { + if (skb) + kfree_skb(skb); return -EINVAL; - ret = tap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT, - m->msg_control); + } + ret = tap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT, skb); if (ret > total_len) { m->msg_flags |= MSG_TRUNC; ret = flags & MSG_TRUNC ? ret : total_len;
Patches currently in stable-queue which might be from wexu@redhat.com are
queue-4.14/tun-free-skb-in-early-errors.patch queue-4.14/vhost-fix-skb-leak-in-handle_rx.patch queue-4.14/tap-free-skb-if-flags-error.patch