On 03.06.19 21:43, David Miller wrote: > From: Julian Wiedmann <jwi@xxxxxxxxxxxxx> > Date: Mon, 3 Jun 2019 17:04:44 +0200 > >> While qeth_l3 uses netif_keep_dst() to hold onto the dst, a skb's dst >> may still have been obsoleted (via dst_dev_put()) by the time that we >> end up using it. The dst then points to the loopback interface, which >> means the neighbour lookup in qeth_l3_get_cast_type() determines a bogus >> cast type of RTN_BROADCAST. >> For IQD interfaces this causes us to place such skbs on the wrong >> HW queue, resulting in TX errors. >> >> Fix-up the various call sites to check whether the dst is obsolete, and >> fall back accordingly. >> >> Signed-off-by: Julian Wiedmann <jwi@xxxxxxxxxxxxx> > > Please use "dst_check()". > > Some routes have DST_OBSOLETE_FORCE_CHK set on them from the very beginning > so that uses of the route are forced through the dst->ops->check() method. > > Simply use dst_check() and then you can just retain the 'rt == NULL' logic > as-is. > > Thanks. > Alright - I was hesitant to go down that path in the context of a driver, but looks like rt6_get_cookie() should do the trick. v2 coming up... thanks.
