Subject: Re: [PATCH net 1/3] sched: cls_bpf: fix panic on filter replace

From: Alexei Starovoitov <[email-masked]>
Date: Fri, 17 Jul 2015 14:31:02 -0700

On 7/17/15 2:05 PM, John Fastabend wrote:
> On 15-07-17 01:38 PM, Daniel Borkmann wrote:
>> >The following test case causes a NULL pointer dereference in cls_bpf:
>> >
>> >   FOO="1,6 0 0 4294967295,"
>> >   tc filter add dev foo parent 1: bpf bytecode "$FOO" flowid 1:1 action ok
>> >   tc filter replace dev foo parent 1: pref 49152 handle 0x1 \
>> >             bpf bytecode "$FOO" flowid 1:1 action drop
>> >
>> >The problem is that commit 1f947bf151e9 ("net: sched: rcu'ify cls_bpf")
>> >accidentally swapped the arguments of list_replace_rcu(), the old
>> >element needs to be the first argument and the new element the second.
>> >
>> >Fixes: 1f947bf151e9 ("net: sched: rcu'ify cls_bpf")
>> >Signed-off-by: Daniel Borkmann<[email-masked]>
>> >---
> Thanks Daniel. Apparently I got this right in cls_basic but botched it
> here and in cls_flow.
>
> FWIW,
>
> Acked-by: John Fastabend<[email-masked]>

Thanks for the quick fix.
Acked-by: Alexei Starovoitov <[email-masked]>