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authorZhang Changzhong <zhangchangzhong@huawei.com>2020-09-07 14:31:48 +0800
committerMarc Kleine-Budde <mkl@pengutronix.de>2020-11-03 22:30:31 +0100
commit08c487d8d807535f509ed80c6a10ad90e6872139 (patch)
tree87d21f6b9fe3b4e9b23653fb7a8545984ef8d4dc
parenta39372c2c597d8ab0b53d953d9c4fc9ba2ed7dd6 (diff)
downloadlinux-08c487d8d807535f509ed80c6a10ad90e6872139.tar.bz2
can: j1939: j1939_sk_bind(): return failure if netdev is down
When a netdev down event occurs after a successful call to j1939_sk_bind(), j1939_netdev_notify() can handle it correctly. But if the netdev already in down state before calling j1939_sk_bind(), j1939_sk_release() will stay in wait_event_interruptible() blocked forever. Because in this case, j1939_netdev_notify() won't be called and j1939_tp_txtimer() won't call j1939_session_cancel() or other function to clear session for ENETDOWN error, this lead to mismatch of j1939_session_get/put() and jsk->skb_pending will never decrease to zero. To reproduce it use following commands: 1. ip link add dev vcan0 type vcan 2. j1939acd -r 100,80-120 1122334455667788 vcan0 3. presses ctrl-c and thread will be blocked forever This patch adds check for ndev->flags in j1939_sk_bind() to avoid this kind of situation and return with -ENETDOWN. Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com> Link: https://lore.kernel.org/r/1599460308-18770-1-git-send-email-zhangchangzhong@huawei.com Acked-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
-rw-r--r--net/can/j1939/socket.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index 1be4c898b2fa..f23966526a88 100644
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -475,6 +475,12 @@ static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len)
goto out_release_sock;
}
+ if (!(ndev->flags & IFF_UP)) {
+ dev_put(ndev);
+ ret = -ENETDOWN;
+ goto out_release_sock;
+ }
+
priv = j1939_netdev_start(ndev);
dev_put(ndev);
if (IS_ERR(priv)) {