4.9-stable review patch. If anyone has any objections, please let me know.
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From: Cong Wang xiyou.wangcong@gmail.com
[ Upstream commit 3a04ce7130a7e5dad4e78d45d50313747f8c830f ]
For SOCK_ZAPPED socket, we don't need to care about llc->sap, so we should just skip these refcount functions in this case.
Fixes: f7e43672683b ("llc: hold llc_sap before release_sock()") Reported-by: kernel test robot lkp@intel.com Signed-off-by: Cong Wang xiyou.wangcong@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/llc/af_llc.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-)
--- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -187,7 +187,6 @@ static int llc_ui_release(struct socket { struct sock *sk = sock->sk; struct llc_sock *llc; - struct llc_sap *sap;
if (unlikely(sk == NULL)) goto out; @@ -198,15 +197,19 @@ static int llc_ui_release(struct socket llc->laddr.lsap, llc->daddr.lsap); if (!llc_send_disc(sk)) llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo); - sap = llc->sap; - /* Hold this for release_sock(), so that llc_backlog_rcv() could still - * use it. - */ - llc_sap_hold(sap); - if (!sock_flag(sk, SOCK_ZAPPED)) + if (!sock_flag(sk, SOCK_ZAPPED)) { + struct llc_sap *sap = llc->sap; + + /* Hold this for release_sock(), so that llc_backlog_rcv() + * could still use it. + */ + llc_sap_hold(sap); llc_sap_remove_socket(llc->sap, sk); - release_sock(sk); - llc_sap_put(sap); + release_sock(sk); + llc_sap_put(sap); + } else { + release_sock(sk); + } if (llc->dev) dev_put(llc->dev); sock_put(sk);