path: root/drivers/net/macsec.c
diff options
authorXin Long <lucien.xin@gmail.com>2019-09-23 17:02:46 +0800
committerDavid S. Miller <davem@davemloft.net>2019-09-26 09:25:03 +0200
commitba56d8ce38c8252fff5b745db3899cf092578ede (patch)
tree183a59a56a2475a55570eff85e7b4501f04aff17 /drivers/net/macsec.c
parentMerge tag 'mlx5-fixes-2019-09-24' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux (diff)
macsec: drop skb sk before calling gro_cells_receive
Fei Liu reported a crash when doing netperf on a topo of macsec dev over veth: [ 448.919128] refcount_t: underflow; use-after-free. [ 449.090460] Call trace: [ 449.092895] refcount_sub_and_test+0xb4/0xc0 [ 449.097155] tcp_wfree+0x2c/0x150 [ 449.100460] ip_rcv+0x1d4/0x3a8 [ 449.103591] __netif_receive_skb_core+0x554/0xae0 [ 449.108282] __netif_receive_skb+0x28/0x78 [ 449.112366] netif_receive_skb_internal+0x54/0x100 [ 449.117144] napi_gro_complete+0x70/0xc0 [ 449.121054] napi_gro_flush+0x6c/0x90 [ 449.124703] napi_complete_done+0x50/0x130 [ 449.128788] gro_cell_poll+0x8c/0xa8 [ 449.132351] net_rx_action+0x16c/0x3f8 [ 449.136088] __do_softirq+0x128/0x320 The issue was caused by skb's true_size changed without its sk's sk_wmem_alloc increased in tcp/skb_gro_receive(). Later when the skb is being freed and the skb's truesize is subtracted from its sk's sk_wmem_alloc in tcp_wfree(), underflow occurs. macsec is calling gro_cells_receive() to receive a packet, which actually requires skb->sk to be NULL. However when macsec dev is over veth, it's possible the skb->sk is still set if the skb was not unshared or expanded from the peer veth. ip_rcv() is calling skb_orphan() to drop the skb's sk for tproxy, but it is too late for macsec's calling gro_cells_receive(). So fix it by dropping the skb's sk earlier on rx path of macsec. Fixes: 5491e7c6b1a9 ("macsec: enable GRO and RPS on macsec devices") Reported-by: Xiumei Mu <xmu@redhat.com> Reported-by: Fei Liu <feliu@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 8f46aa1ddec0..cb7637364b40 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -1235,6 +1235,7 @@ deliver:
+ skb_orphan(skb);
ret = gro_cells_receive(&macsec->gro_cells, skb);
if (ret == NET_RX_SUCCESS)
count_rx(dev, skb->len);