Fix an issue with relying on netif_running() which could be true during when dev->open() handler is being called, even if it would exit with a failure. This ensures the state does not get set and removed with a narrow race for other callers to read it as open when infact it never finished opening.
Signed-off-by: Jacob Keller <jacob.e.kel...@intel.com> --- I found this as a result of debugging a race condition in the i40evf driver, in which we assumed that netif_running() would not be true until after dev->open() had been called and succeeded. Unfortunately we can't hold the rtnl_lock() while checking netif_running() because it would cause a deadlock between our reset task and our ndo_open handler. I am wondering whether the proposed change is acceptable here, or whether some ndo_open handlers rely on __LINK_STATE_START being true prior to their being called? net/core/dev.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 1d75499add72..11953af90427 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1362,8 +1362,6 @@ static int __dev_open(struct net_device *dev) if (ret) return ret; - set_bit(__LINK_STATE_START, &dev->state); - if (ops->ndo_validate_addr) ret = ops->ndo_validate_addr(dev); @@ -1372,9 +1370,8 @@ static int __dev_open(struct net_device *dev) netpoll_poll_enable(dev); - if (ret) - clear_bit(__LINK_STATE_START, &dev->state); - else { + if (!ret) + set_bit(__LINK_STATE_START, &dev->state); dev->flags |= IFF_UP; dev_set_rx_mode(dev); dev_activate(dev); -- 2.14.0.rc1.251.g593d8d6362ce