diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index 5f9373ee47cec05fd55660ced15d7339359228b7..266fcb34fefe0189acf8f4b17f7decf0b78bd13e 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -163,6 +163,23 @@ static inline u32 tcf_auto_prio(struct tcf_proto *tp) return TC_H_MAJ(first); } +static bool tcf_proto_is_unlocked(const char *kind) +{ + const struct tcf_proto_ops *ops; + bool ret; + + ops = tcf_proto_lookup_ops(kind, false, NULL); + /* On error return false to take rtnl lock. Proto lookup/create + * functions will perform lookup again and properly handle errors. + */ + if (IS_ERR(ops)) + return false; + + ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED); + module_put(ops->owner); + return ret; +} + static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol, u32 prio, struct tcf_chain *chain, bool rtnl_held, @@ -1312,8 +1329,12 @@ static void tcf_block_release(struct Qdisc *q, struct tcf_block *block, if (!IS_ERR_OR_NULL(block)) tcf_block_refcnt_put(block, rtnl_held); - if (q) - qdisc_put(q); + if (q) { + if (rtnl_held) + qdisc_put(q); + else + qdisc_put_unlocked(q); + } } struct tcf_block_owner_item { @@ -1966,7 +1987,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *fh; int err; int tp_created; - bool rtnl_held = true; + bool rtnl_held = false; if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; @@ -1985,6 +2006,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n, parent = t->tcm_parent; tp = NULL; cl = 0; + block = NULL; if (prio == 0) { /* If no priority is provided by the user, @@ -2001,8 +2023,27 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n, /* Find head of filter chain. */ - block = tcf_block_find(net, &q, &parent, &cl, - t->tcm_ifindex, t->tcm_block_index, extack); + err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack); + if (err) + return err; + + /* Take rtnl mutex if rtnl_held was set to true on previous iteration, + * block is shared (no qdisc found), qdisc is not unlocked, classifier + * type is not specified, classifier is not unlocked. + */ + if (rtnl_held || + (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) || + !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) { + rtnl_held = true; + rtnl_lock(); + } + + err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack); + if (err) + goto errout; + + block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index, + extack); if (IS_ERR(block)) { err = PTR_ERR(block); goto errout; @@ -2123,9 +2164,18 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n, tcf_chain_put(chain); } tcf_block_release(q, block, rtnl_held); - if (err == -EAGAIN) + + if (rtnl_held) + rtnl_unlock(); + + if (err == -EAGAIN) { + /* Take rtnl lock in case EAGAIN is caused by concurrent flush + * of target chain. + */ + rtnl_held = true; /* Replay the request. */ goto replay; + } return err; errout_locked: @@ -2146,12 +2196,12 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n, struct Qdisc *q = NULL; struct tcf_chain_info chain_info; struct tcf_chain *chain = NULL; - struct tcf_block *block; + struct tcf_block *block = NULL; struct tcf_proto *tp = NULL; unsigned long cl = 0; void *fh = NULL; int err; - bool rtnl_held = true; + bool rtnl_held = false; if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; @@ -2172,8 +2222,27 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n, /* Find head of filter chain. */ - block = tcf_block_find(net, &q, &parent, &cl, - t->tcm_ifindex, t->tcm_block_index, extack); + err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack); + if (err) + return err; + + /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc + * found), qdisc is not unlocked, classifier type is not specified, + * classifier is not unlocked. + */ + if (!prio || + (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) || + !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) { + rtnl_held = true; + rtnl_lock(); + } + + err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack); + if (err) + goto errout; + + block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index, + extack); if (IS_ERR(block)) { err = PTR_ERR(block); goto errout; @@ -2255,6 +2324,10 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n, tcf_chain_put(chain); } tcf_block_release(q, block, rtnl_held); + + if (rtnl_held) + rtnl_unlock(); + return err; errout_locked: @@ -2275,12 +2348,12 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n, struct Qdisc *q = NULL; struct tcf_chain_info chain_info; struct tcf_chain *chain = NULL; - struct tcf_block *block; + struct tcf_block *block = NULL; struct tcf_proto *tp = NULL; unsigned long cl = 0; void *fh = NULL; int err; - bool rtnl_held = true; + bool rtnl_held = false; err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, rtm_tca_policy, extack); if (err < 0) @@ -2298,8 +2371,26 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n, /* Find head of filter chain. */ - block = tcf_block_find(net, &q, &parent, &cl, - t->tcm_ifindex, t->tcm_block_index, extack); + err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack); + if (err) + return err; + + /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not + * unlocked, classifier type is not specified, classifier is not + * unlocked. + */ + if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) || + !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) { + rtnl_held = true; + rtnl_lock(); + } + + err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack); + if (err) + goto errout; + + block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index, + extack); if (IS_ERR(block)) { err = PTR_ERR(block); goto errout; @@ -2352,6 +2443,10 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n, tcf_chain_put(chain); } tcf_block_release(q, block, rtnl_held); + + if (rtnl_held) + rtnl_unlock(); + return err; } @@ -3214,10 +3309,12 @@ static int __init tc_filter_init(void) if (err) goto err_rhash_setup_block_ht; - rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL, 0); - rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL, 0); + rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL, + RTNL_FLAG_DOIT_UNLOCKED); + rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL, + RTNL_FLAG_DOIT_UNLOCKED); rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter, - tc_dump_tfilter, 0); + tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED); rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0); rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0); rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,