From 2adc6edcaec09eea9275915e9632ff916fcd0785 Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Tue, 1 Sep 2020 18:52:32 +0100 Subject: ethtool: fix error handling in ethtool_phys_id If ops->set_phys_id() returned an error, previously we would only break out of the inner loop, which neither stopped the outer loop nor returned the error to the user (since 'rc' would be overwritten on the next pass through the loop). Thus, rewrite it to use a single loop, so that the break does the right thing. Use u64 for 'count' and 'i' to prevent overflow in case of (unreasonably) large values of id.data and n. Signed-off-by: Edward Cree Signed-off-by: David S. Miller --- net/ethtool/ioctl.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) (limited to 'net/ethtool') diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index d497ca064ef7..328d15cd4006 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -1861,23 +1861,18 @@ static int ethtool_phys_id(struct net_device *dev, void __user *useraddr) id.data ? (id.data * HZ) : MAX_SCHEDULE_TIMEOUT); } else { /* Driver expects to be called at twice the frequency in rc */ - int n = rc * 2, i, interval = HZ / n; + int n = rc * 2, interval = HZ / n; + u64 count = n * id.data, i = 0; - /* Count down seconds */ do { - /* Count down iterations per second */ - i = n; - do { - rtnl_lock(); - rc = ops->set_phys_id(dev, - (i & 1) ? ETHTOOL_ID_OFF : ETHTOOL_ID_ON); - rtnl_unlock(); - if (rc) - break; - schedule_timeout_interruptible(interval); - } while (!signal_pending(current) && --i != 0); - } while (!signal_pending(current) && - (id.data == 0 || --id.data != 0)); + rtnl_lock(); + rc = ops->set_phys_id(dev, + (i++ & 1) ? ETHTOOL_ID_OFF : ETHTOOL_ID_ON); + rtnl_unlock(); + if (rc) + break; + schedule_timeout_interruptible(interval); + } while (!signal_pending(current) && (!id.data || i < count)); } rtnl_lock(); -- cgit v1.2.3