From: Davide Caratti <dcara...@redhat.com> Date: Sat, 16 Sep 2017 14:02:21 +0200
> this script, edited from Linux Advanced Routing and Traffic Control guide > > tc q a dev en0 root handle 1: htb default a > tc c a dev en0 parent 1: classid 1:1 htb rate 6mbit burst 15k > tc c a dev en0 parent 1:1 classid 1:a htb rate 5mbit ceil 6mbit burst 15k > tc c a dev en0 parent 1:1 classid 1:b htb rate 1mbit ceil 6mbit burst 15k > tc f a dev en0 parent 1:0 prio 1 $clsname $clsargs classid 1:b > ping $address -c1 > tc -s c s dev en0 > > classifies traffic to 1:b or 1:a, depending on whether the packet matches > or not the pattern $clsargs of filter $clsname. However, when $clsname is > 'matchall', a systematic crash can be observed in htb_classify(). HTB and > classful qdiscs don't assign initial value to struct tcf_result, but then > they expect it to contain valid values after filters have been run. Thus, > current 'matchall' ignores the TCA_MATCHALL_CLASSID attribute, configured > by user, and makes HTB (and classful qdiscs) dereference random pointers. > > By assigning head->res to *res in mall_classify(), before the actions are > invoked, we fix this crash and enable TCA_MATCHALL_CLASSID functionality, > that had no effect on 'matchall' classifier since its first introduction. > > BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1460213 > Reported-by: Jiri Benc <jb...@redhat.com> > Fixes: b87f7936a932 ("net/sched: introduce Match-all classifier") > Signed-off-by: Davide Caratti <dcara...@redhat.com> Applied and queued up for -stable, thanks.
