From: Eric Dumazet edumazet@google.com
commit 764f4eb6846f5475f1244767d24d25dd86528a4a upstream.
Whenever llc_ui_bind() and/or llc_ui_autobind() took a reference on a netdevice but subsequently fail, they must properly release their reference or risk the infamous message from unregister_netdevice() at device dismantle.
unregister_netdevice: waiting for eth0 to become free. Usage count = 3
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: 赵子轩 beraphin@gmail.com Reported-by: Stoyan Manolov smanolov@suse.de Link: https://lore.kernel.org/r/20220323004147.1990845-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/llc/af_llc.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -310,6 +310,10 @@ static int llc_ui_autobind(struct socket sock_reset_flag(sk, SOCK_ZAPPED); rc = 0; out: + if (rc) { + dev_put(llc->dev); + llc->dev = NULL; + } return rc; }
@@ -407,6 +411,10 @@ static int llc_ui_bind(struct socket *so out_put: llc_sap_put(sap); out: + if (rc) { + dev_put(llc->dev); + llc->dev = NULL; + } release_sock(sk); return rc; }