On Wed, Apr 12, 2017 at 7:21 AM, Wolfgang Bumiller
<w.bumil...@proxmox.com> wrote:
> If memory allocation for nla_memdup_cookie() fails
> module_put has to be guarded by the same condition as it was
> before the TCA_ACT_COOKIE has been added as stated in the
> comment afterwards:
>
> /* module count goes up only when brand new policy is created
> * if it exists and is only bound to in a_o->init() then
> * ACT_P_CREATED is not returned (a zero is).
> */
Yeah, this patch makes sense for me too. Just one comment below.
>
> Signed-off-by: Wolfgang Bumiller <w.bumil...@proxmox.com>
> ---
>
> Note that I'm unsure about this patch. The hangups weren't very reliable
> and I couldn't actually reproduce them when building from git/master (as
> I can only test a fraction of my usual workload with it as a lot of my
> data (VMs & containers utilizing veths and tap devices) is on ZFS...).
> In any case it can't harm to take another look at the error handling
> here.
>
> net/sched/act_api.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/net/sched/act_api.c b/net/sched/act_api.c
> index 8cc883c063f0..795ac092b723 100644
> --- a/net/sched/act_api.c
> +++ b/net/sched/act_api.c
> @@ -608,15 +608,19 @@ struct tc_action *tcf_action_init_1(struct net *net,
> struct nlattr *nla,
> int cklen = nla_len(tb[TCA_ACT_COOKIE]);
>
> if (cklen > TC_COOKIE_MAX_SIZE) {
> - err = -EINVAL;
> tcf_hash_release(a, bind);
> - goto err_mod;
> + if (err != ACT_P_CREATED)
> + module_put(a_o->owner);
> + err = -EINVAL;
> + goto err_out;
> }
>
> if (nla_memdup_cookie(a, tb) < 0) {
> - err = -ENOMEM;
> tcf_hash_release(a, bind);
> - goto err_mod;
> + if (err != ACT_P_CREATED)
> + module_put(a_o->owner);
> + err = -ENOMEM;
> + goto err_out;
Instead of duplicating code, you can add the check
to the module_put() next to err_mod label? I mean:
@@ -630,7 +630,8 @@ struct tc_action *tcf_action_init_1(struct net
*net, struct nlattr *nla,
return a;
err_mod:
- module_put(a_o->owner);
+ if (err != ACT_P_CREATED)
+ module_put(a_o->owner);
err_out:
return ERR_PTR(err);
}
