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| author | Zhang Changzhong <zhangchangzhong@huawei.com> | 2020-09-07 14:31:48 +0800 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2020-11-03 22:30:31 +0100 |
| commit | 08c487d8d807535f509ed80c6a10ad90e6872139 (patch) | |
| tree | 87d21f6b9fe3b4e9b23653fb7a8545984ef8d4dc /net | |
| parent | a39372c2c597d8ab0b53d953d9c4fc9ba2ed7dd6 (diff) | |
| download | linux-08c487d8d807535f509ed80c6a10ad90e6872139.tar.gz linux-08c487d8d807535f509ed80c6a10ad90e6872139.tar.bz2 linux-08c487d8d807535f509ed80c6a10ad90e6872139.zip | |
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/can/j1939/socket.c | 6 |
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)) { |