From: Victor Nogueira victor@mojatatu.com
commit 76b39b94382f9e0a639e1c70c3253de248cc4c83 upstream.
If during an action flush operation one of the actions is still being referenced, the flush operation is aborted and the kernel returns to user space with an error. However, if the kernel was able to flush, for example, 3 actions and failed on the fourth, the kernel will not notify user space that it deleted 3 actions before failing.
This patch fixes that behaviour by notifying user space of how many actions were deleted before flush failed and by setting extack with a message describing what happened.
Fixes: 55334a5db5cd ("net_sched: act: refuse to remove bound action outside") Signed-off-by: Victor Nogueira victor@mojatatu.com Acked-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/act_api.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-)
--- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -588,7 +588,8 @@ static int tcf_idr_release_unsafe(struct }
static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb, - const struct tc_action_ops *ops) + const struct tc_action_ops *ops, + struct netlink_ext_ack *extack) { struct nlattr *nest; int n_i = 0; @@ -604,20 +605,25 @@ static int tcf_del_walker(struct tcf_idr if (nla_put_string(skb, TCA_KIND, ops->kind)) goto nla_put_failure;
+ ret = 0; mutex_lock(&idrinfo->lock); idr_for_each_entry_ul(idr, p, tmp, id) { if (IS_ERR(p)) continue; ret = tcf_idr_release_unsafe(p); - if (ret == ACT_P_DELETED) { + if (ret == ACT_P_DELETED) module_put(ops->owner); - n_i++; - } else if (ret < 0) { - mutex_unlock(&idrinfo->lock); - goto nla_put_failure; - } + else if (ret < 0) + break; + n_i++; } mutex_unlock(&idrinfo->lock); + if (ret < 0) { + if (n_i) + NL_SET_ERR_MSG(extack, "Unable to flush all TC actions"); + else + goto nla_put_failure; + }
ret = nla_put_u32(skb, TCA_FCNT, n_i); if (ret) @@ -638,7 +644,7 @@ int tcf_generic_walker(struct tc_action_ struct tcf_idrinfo *idrinfo = tn->idrinfo;
if (type == RTM_DELACTION) { - return tcf_del_walker(idrinfo, skb, ops); + return tcf_del_walker(idrinfo, skb, ops, extack); } else if (type == RTM_GETACTION) { return tcf_dump_walker(idrinfo, skb, cb); } else {