This is a note to let you know that I've just added the patch titled

net: hns: Fix a skb used after free bug

to the 4.9-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: net-hns-fix-a-skb-used-after-free-bug.patch and it can be found in the queue-4.9 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 27463ad99f738ed93c7c8b3e2e5bc8c4853a2ff2 Mon Sep 17 00:00:00 2001

From: Yunsheng Lin linyunsheng@huawei.com Date: Thu, 6 Jul 2017 10:22:00 +0800 Subject: net: hns: Fix a skb used after free bug

From: Yunsheng Lin linyunsheng@huawei.com

commit 27463ad99f738ed93c7c8b3e2e5bc8c4853a2ff2 upstream.

skb maybe freed in hns_nic_net_xmit_hw() and return NETDEV_TX_OK, which cause hns_nic_net_xmit to use a freed skb.

BUG: KASAN: use-after-free in hns_nic_net_xmit_hw+0x62c/0x940... [17659.112635] alloc_debug_processing+0x18c/0x1a0 [17659.117208] __slab_alloc+0x52c/0x560 [17659.120909] kmem_cache_alloc_node+0xac/0x2c0 [17659.125309] __alloc_skb+0x6c/0x260 [17659.128837] tcp_send_ack+0x8c/0x280 [17659.132449] __tcp_ack_snd_check+0x9c/0xf0 [17659.136587] tcp_rcv_established+0x5a4/0xa70 [17659.140899] tcp_v4_do_rcv+0x27c/0x620 [17659.144687] tcp_prequeue_process+0x108/0x170 [17659.149085] tcp_recvmsg+0x940/0x1020 [17659.152787] inet_recvmsg+0x124/0x180 [17659.156488] sock_recvmsg+0x64/0x80 [17659.160012] SyS_recvfrom+0xd8/0x180 [17659.163626] __sys_trace_return+0x0/0x4 [17659.167506] INFO: Freed in kfree_skbmem+0xa0/0xb0 age=23 cpu=1 pid=13 [17659.174000] free_debug_processing+0x1d4/0x2c0 [17659.178486] __slab_free+0x240/0x390 [17659.182100] kmem_cache_free+0x24c/0x270 [17659.186062] kfree_skbmem+0xa0/0xb0 [17659.189587] __kfree_skb+0x28/0x40 [17659.193025] napi_gro_receive+0x168/0x1c0 [17659.197074] hns_nic_rx_up_pro+0x58/0x90 [17659.201038] hns_nic_rx_poll_one+0x518/0xbc0 [17659.205352] hns_nic_common_poll+0x94/0x140 [17659.209576] net_rx_action+0x458/0x5e0 [17659.213363] __do_softirq+0x1b8/0x480 [17659.217062] run_ksoftirqd+0x64/0x80 [17659.220679] smpboot_thread_fn+0x224/0x310 [17659.224821] kthread+0x150/0x170 [17659.228084] ret_from_fork+0x10/0x40

BUG: KASAN: use-after-free in hns_nic_net_xmit+0x8c/0xc0... [17751.080490] __slab_alloc+0x52c/0x560 [17751.084188] kmem_cache_alloc+0x244/0x280 [17751.088238] __build_skb+0x40/0x150 [17751.091764] build_skb+0x28/0x100 [17751.095115] __alloc_rx_skb+0x94/0x150 [17751.098900] __napi_alloc_skb+0x34/0x90 [17751.102776] hns_nic_rx_poll_one+0x180/0xbc0 [17751.107097] hns_nic_common_poll+0x94/0x140 [17751.111333] net_rx_action+0x458/0x5e0 [17751.115123] __do_softirq+0x1b8/0x480 [17751.118823] run_ksoftirqd+0x64/0x80 [17751.122437] smpboot_thread_fn+0x224/0x310 [17751.126575] kthread+0x150/0x170 [17751.129838] ret_from_fork+0x10/0x40 [17751.133454] INFO: Freed in kfree_skbmem+0xa0/0xb0 age=19 cpu=7 pid=43 [17751.139951] free_debug_processing+0x1d4/0x2c0 [17751.144436] __slab_free+0x240/0x390 [17751.148051] kmem_cache_free+0x24c/0x270 [17751.152014] kfree_skbmem+0xa0/0xb0 [17751.155543] __kfree_skb+0x28/0x40 [17751.159022] napi_gro_receive+0x168/0x1c0 [17751.163074] hns_nic_rx_up_pro+0x58/0x90 [17751.167041] hns_nic_rx_poll_one+0x518/0xbc0 [17751.171358] hns_nic_common_poll+0x94/0x140 [17751.175585] net_rx_action+0x458/0x5e0 [17751.179373] __do_softirq+0x1b8/0x480 [17751.183076] run_ksoftirqd+0x64/0x80 [17751.186691] smpboot_thread_fn+0x224/0x310 [17751.190826] kthread+0x150/0x170 [17751.194093] ret_from_fork+0x10/0x40

Fixes: 13ac695e7ea1 ("net:hns: Add support of Hip06 SoC to the Hislicon Network Subsystem") Signed-off-by: Yunsheng Lin linyunsheng@huawei.com Signed-off-by: lipeng lipeng321@huawei.com Reported-by: Jun He hjat2005@huawei.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Erick Reyes erickreyes@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/net/ethernet/hisilicon/hns/hns_enet.c | 22 ++++++++++------------ drivers/net/ethernet/hisilicon/hns/hns_enet.h | 6 +++--- 2 files changed, 13 insertions(+), 15 deletions(-)

--- a/drivers/net/ethernet/hisilicon/hns/hns_enet.c +++ b/drivers/net/ethernet/hisilicon/hns/hns_enet.c @@ -299,9 +299,9 @@ static void fill_tso_desc(struct hnae_ri mtu); }

-int hns_nic_net_xmit_hw(struct net_device *ndev, - struct sk_buff *skb, - struct hns_nic_ring_data *ring_data) +netdev_tx_t hns_nic_net_xmit_hw(struct net_device *ndev, + struct sk_buff *skb, + struct hns_nic_ring_data *ring_data) { struct hns_nic_priv *priv = netdev_priv(ndev); struct hnae_ring *ring = ring_data->ring; @@ -360,6 +360,10 @@ int hns_nic_net_xmit_hw(struct net_devic dev_queue = netdev_get_tx_queue(ndev, skb->queue_mapping); netdev_tx_sent_queue(dev_queue, skb->len);

+ netif_trans_update(ndev); + ndev->stats.tx_bytes += skb->len; + ndev->stats.tx_packets++; + wmb(); /* commit all data before submit */ assert(skb->queue_mapping < priv->ae_handle->q_num); hnae_queue_xmit(priv->ae_handle->qs[skb->queue_mapping], buf_num); @@ -1408,17 +1412,11 @@ static netdev_tx_t hns_nic_net_xmit(stru struct net_device *ndev) { struct hns_nic_priv *priv = netdev_priv(ndev); - int ret;

assert(skb->queue_mapping < ndev->ae_handle->q_num); - ret = hns_nic_net_xmit_hw(ndev, skb, - &tx_ring_data(priv, skb->queue_mapping)); - if (ret == NETDEV_TX_OK) { - netif_trans_update(ndev); - ndev->stats.tx_bytes += skb->len; - ndev->stats.tx_packets++; - } - return (netdev_tx_t)ret; + + return hns_nic_net_xmit_hw(ndev, skb, + &tx_ring_data(priv, skb->queue_mapping)); }

static int hns_nic_change_mtu(struct net_device *ndev, int new_mtu) --- a/drivers/net/ethernet/hisilicon/hns/hns_enet.h +++ b/drivers/net/ethernet/hisilicon/hns/hns_enet.h @@ -91,8 +91,8 @@ void hns_ethtool_set_ops(struct net_devi void hns_nic_net_reset(struct net_device *ndev); void hns_nic_net_reinit(struct net_device *netdev); int hns_nic_init_phy(struct net_device *ndev, struct hnae_handle *h); -int hns_nic_net_xmit_hw(struct net_device *ndev, - struct sk_buff *skb, - struct hns_nic_ring_data *ring_data); +netdev_tx_t hns_nic_net_xmit_hw(struct net_device *ndev, + struct sk_buff *skb, + struct hns_nic_ring_data *ring_data);

#endif /**__HNS_ENET_H */

Patches currently in stable-queue which might be from linyunsheng@huawei.com are

queue-4.9/net-hns-fix-a-skb-used-after-free-bug.patch