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| author | Vlad Buslov <vladbu@nvidia.com> | 2021-04-07 18:36:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-04-14 09:42:02 +0300 |
| commit | 81692c6add7e55309bdc275f59301efd4b49e958 (patch) | |
| tree | d8be56946afd81fee1a71e2d24a0f43123fb68ff /include/net | |
| parent | cdcf3829f418d9d85c720bbd25ab9fb4b6c2e056 (diff) | |
| download | linux-81692c6add7e55309bdc275f59301efd4b49e958.tar.xz | |
net: sched: fix action overwrite reference counting
commit 87c750e8c38bce706eb32e4d8f1e3402f2cebbd4 upstream.
Action init code increments reference counter when it changes an action.
This is the desired behavior for cls API which needs to obtain action
reference for every classifier that points to action. However, act API just
needs to change the action and releases the reference before returning.
This sequence breaks when the requested action doesn't exist, which causes
act API init code to create new action with specified index, but action is
still released before returning and is deleted (unless it was referenced
concurrently by cls API).
Reproduction:
$ sudo tc actions ls action gact
$ sudo tc actions change action gact drop index 1
$ sudo tc actions ls action gact
Extend tcf_action_init() to accept 'init_res' array and initialize it with
action->ops->init() result. In tcf_action_add() remove pointers to created
actions from actions array before passing it to tcf_action_put_many().
Fixes: cae422f379f3 ("net: sched: use reference counting action init")
Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/act_api.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/net/act_api.h b/include/net/act_api.h index 89b42a1e4f88..27786090ae8e 100644 --- a/include/net/act_api.h +++ b/include/net/act_api.h @@ -185,7 +185,7 @@ int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions, int nr_actions, struct tcf_result *res); int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla, struct nlattr *est, char *name, int ovr, int bind, - struct tc_action *actions[], size_t *attr_size, + struct tc_action *actions[], int init_res[], size_t *attr_size, bool rtnl_held, struct netlink_ext_ack *extack); struct tc_action_ops *tc_action_load_ops(char *name, struct nlattr *nla, bool rtnl_held, @@ -193,7 +193,8 @@ struct tc_action_ops *tc_action_load_ops(char *name, struct nlattr *nla, struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp, struct nlattr *nla, struct nlattr *est, char *name, int ovr, int bind, - struct tc_action_ops *ops, bool rtnl_held, + struct tc_action_ops *a_o, int *init_res, + bool rtnl_held, struct netlink_ext_ack *extack); int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[], int bind, int ref, bool terse); |