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authorHeiner Kallweit <hkallweit1@gmail.com>2018-09-18 21:55:36 +0200
committerDavid S. Miller <davem@davemloft.net>2018-09-19 21:06:46 -0700
commit124eee3f6955f7aa19b9e6ff5c9b6d37cb3d1e2c (patch)
treefb42d27e933440f5295eaace7a973b3e830011d1 /net/core/link_watch.c
parent822143acf94f647aba7ed2e20e0e629485c1e43d (diff)
downloadlinux-124eee3f6955f7aa19b9e6ff5c9b6d37cb3d1e2c.tar.bz2
net: linkwatch: add check for netdevice being present to linkwatch_do_dev
When bringing down the netdevice (incl. detaching it) and calling netif_carrier_off directly or indirectly the latter triggers an asynchronous linkwatch event. This linkwatch event eventually may fail to access chip registers in the ndo_get_stats/ndo_get_stats64 callback because the device isn't accessible any longer, see call trace in [0]. To prevent this scenario don't check for IFF_UP only, but also make sure that the netdevice is present. [0] https://lists.openwall.net/netdev/2018/03/15/62 Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/link_watch.c')
-rw-r--r--net/core/link_watch.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/link_watch.c b/net/core/link_watch.c
index e38e641e98d5..7f51efb2b3ab 100644
--- a/net/core/link_watch.c
+++ b/net/core/link_watch.c
@@ -155,7 +155,7 @@ static void linkwatch_do_dev(struct net_device *dev)
clear_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state);
rfc2863_policy(dev);
- if (dev->flags & IFF_UP) {
+ if (dev->flags & IFF_UP && netif_device_present(dev)) {
if (netif_carrier_ok(dev))
dev_activate(dev);
else