xfrm: release all offloaded policy memory

BugLink: https://bugs.launchpad.net/bugs/2028808
[ Upstream commit 94b95dfaa814f565d92f5a65f0ff12a483095522 ]

Failure to add offloaded policy will cause to the following
error once user will try to reload driver.

Unregister_netdevice: waiting for eth3 to become free. Usage count = 2

This was caused by xfrm_dev_policy_add() which increments reference
to net_device. That reference was supposed to be decremented
in xfrm_dev_policy_free(). However the latter wasn't called.

 unregister_netdevice: waiting for eth3 to become free. Usage count = 2
 leaked reference.
  xfrm_dev_policy_add+0xff/0x3d0
  xfrm_policy_construct+0x352/0x420
  xfrm_add_policy+0x179/0x320
  xfrm_user_rcv_msg+0x1d2/0x3d0
  netlink_rcv_skb+0xe0/0x210
  xfrm_netlink_rcv+0x45/0x50
  netlink_unicast+0x346/0x490
  netlink_sendmsg+0x3b0/0x6c0
  sock_sendmsg+0x73/0xc0
  sock_write_iter+0x13b/0x1f0
  vfs_write+0x528/0x5d0
  ksys_write+0x120/0x150
  do_syscall_64+0x3d/0x90
  entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fixes: 919e43fad516 ("xfrm: add an interface to offload policy")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 051c4c45658c17518d454d945b915bb8edd70ba5..6794b9dea27aadae31d52d85716dfddfdceef7bf 100644 (file)
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1982,6 +1982,7 @@ static int xfrm_add_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
 
        if (err) {
                xfrm_dev_policy_delete(xp);
+               xfrm_dev_policy_free(xp);
                security_xfrm_policy_free(xp->security);
                kfree(xp);
                return err;