[PATCH] can: etas_es58x: fix error handling

Pavel Skripkin
2021-11-14T20:59:41Z

When register_candev() fails there are 2 possible device states:
NETREG_UNINITIALIZED and NETREG_UNREGISTERED. None of them are suitable
for calling unregister_candev(), because of following checks in
unregister_netdevice_many():

if (dev->reg_state == NETREG_UNINITIALIZED)
WARN_ON(1);
...
BUG_ON(dev->reg_state != NETREG_REGISTERED);

To avoid possible BUG_ON or WARN_ON let's free current netdev before
returning from es58x_init_netdev() and leave others (registered)
net devices for es58x_free_netdevs().

Fixes: 004653f0abf2 ("can: etas_es58x: add es58x_free_netdevs() to factorize code")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
drivers/net/can/usb/etas_es58x/es58x_core.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c
index 96a13c770e4a..41c721f2fbbe 100644
--- a/drivers/net/can/usb/etas_es58x/es58x_core.c
+++ b/drivers/net/can/usb/etas_es58x/es58x_core.c
@@ -2098,8 +2098,11 @@ static int es58x_init_netdev(struct es58x_device *es58x_dev, int channel_idx)
netdev->flags |= IFF_ECHO; /* We support local echo */

ret = register_candev(netdev);
- if (ret)
+ if (ret) {
+ free_candev(netdev);
+ es58x_dev->netdev[channel_idx] = NULL;
return ret;
+ }

netdev_queue_set_dql_min_limit(netdev_get_tx_queue(netdev, 0),
es58x_dev->param->dql_min_limit);
--
2.33.1