On Wed, Mar 14, 2018 at 3:43 PM, Davide Caratti <dcara...@redhat.com> wrote:
> hello Cong, thank you for reviewing this.
>
> On Wed, 2018-03-14 at 11:41 -0700, Cong Wang wrote:
>> On Tue, Mar 13, 2018 at 7:13 PM, Davide Caratti <dcara...@redhat.com> wrote:
>>
>> Looks like we just need to replace the tcf_idr_cleanup() with
>> tcf_idr_release()? Which is also simpler.
>
> I just tried it on act_simple, and I can confirm: 'index' does not leak
> anymore if alloc_defdata() fails to kzalloc(), and then tcf_idr_release()
> is called in place of of tcf_idr_cleanup().
Good.
>
>> Looks like all other callers of tcf_idr_cleanup() need to be replaced too,
>> but I don't audit all of them...
>
> no problem, I can try to do that, it's not going to be a big series
> anyway.
Please audit all of them.
>
> while at it, I will also fix other spots where the same bug can be
> reproduced, even if tcf_idr_cleanup() is not there: for example, when
> tcf_vlan_init() fails allocating struct tcf_vlan_params *p,
>
> ASSERT_RTNL();
> p = kzalloc(sizeof(*p), GFP_KERNEL);
> if (!p) {
> if (ovr)
> tcf_idr_release(*a, bind);
> return -ENOMEM;
> }
>
> the followinng behavior can be observed:
>
> # tc actions flush action vlan
> # tc actions add action vlan pop index 5
> RTNETLINK answers: Cannot allocate memory
> We have an error talking to the kernel
> # tc actions add action vlan pop index 5
> RTNETLINK answers: No space left on device
> We have an error talking to the kernel
> # tc actions add action vlan pop index 5
> RTNETLINK answers: No space left on device
> We have an error talking to the kernel
>
> Probably testing the value of 'ovr' here is wrong, or maybe it's
> not enough: I will also verify what happens using 'replace'
> keyword instead of 'add'.
Please fix it separately if really needed, and it would be nicer
if you can add your test cases to tools/testing/selftests/tc-testing/.
Thanks!
