diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 4111d53f46569ceba9fd2030110a35163fcc45fa..e72d46813125e47b493164acdc706dfb5e4f7e80 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -295,6 +295,8 @@ struct netlink_callback { u32 min_dump_alloc; unsigned int prev_seq, seq; bool strict_check; + KABI_FILL_HOLE(int flags) + union { u8 ctx[48]; @@ -326,6 +328,7 @@ struct netlink_dump_control { void *data; struct module *module; u32 min_dump_alloc; + KABI_FILL_HOLE(int flags) }; int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h index 318b3168e77b9e7941ec69030c893f2c6bc82671..365e36a19c498fb53aa3c616cf3c5df516999d27 100644 --- a/include/net/rtnetlink.h +++ b/include/net/rtnetlink.h @@ -13,6 +13,7 @@ typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *); enum rtnl_link_flags { RTNL_FLAG_DOIT_UNLOCKED = BIT(0), RTNL_FLAG_BULK_DEL_SUPPORTED = BIT(1), + RTNL_FLAG_DUMP_UNLOCKED = BIT(2), }; enum rtnl_kinds { diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 71775e1e9c391a08108bec42c3ff78aef85ede0b..4acde7067519ee845a2b4460bef0d585e15eaa5b 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -6405,6 +6405,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, } owner = link->owner; dumpit = link->dumpit; + flags = link->flags; if (type == RTM_GETLINK - RTM_BASE) min_dump_alloc = rtnl_calcit(skb, nlh); @@ -6422,6 +6423,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, .dump = dumpit, .min_dump_alloc = min_dump_alloc, .module = owner, + .flags = flags, }; err = netlink_dump_start(rtnl, skb, nlh, &c); /* netlink_dump_start() will keep a reference on diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 7b609284bf78d088bb6175c092012778c56a3c60..4aa2cbe9d6fa69957fd99025ba72f5932fdc8287 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -619,7 +619,7 @@ static struct proto netlink_proto = { }; static int __netlink_create(struct net *net, struct socket *sock, - struct mutex *cb_mutex, int protocol, + struct mutex *dump_cb_mutex, int protocol, int kern) { struct sock *sk; @@ -634,15 +634,11 @@ static int __netlink_create(struct net *net, struct socket *sock, sock_init_data(sock, sk); nlk = nlk_sk(sk); - if (cb_mutex) { - nlk->cb_mutex = cb_mutex; - } else { - nlk->cb_mutex = &nlk->cb_def_mutex; - mutex_init(nlk->cb_mutex); - lockdep_set_class_and_name(nlk->cb_mutex, + mutex_init(&nlk->nl_cb_mutex); + lockdep_set_class_and_name(&nlk->nl_cb_mutex, nlk_cb_mutex_keys + protocol, nlk_cb_mutex_key_strings[protocol]); - } + nlk->dump_cb_mutex = dump_cb_mutex; init_waitqueue_head(&nlk->wait); sk->sk_destruct = netlink_sock_destruct; @@ -2197,7 +2193,7 @@ static int netlink_dump(struct sock *sk, bool lock_taken) int alloc_size; if (!lock_taken) - mutex_lock(nlk->cb_mutex); + mutex_lock(&nlk->nl_cb_mutex); if (!nlk->cb_running) { err = -EINVAL; goto errout_skb; @@ -2249,14 +2245,24 @@ static int netlink_dump(struct sock *sk, bool lock_taken) netlink_skb_set_owner_r(skb, sk); if (nlk->dump_done_errno > 0) { + struct mutex *extra_mutex = nlk->dump_cb_mutex; + cb->extack = &extack; + + if (cb->flags & RTNL_FLAG_DUMP_UNLOCKED) + extra_mutex = NULL; + if (extra_mutex) + mutex_lock(extra_mutex); nlk->dump_done_errno = cb->dump(skb, cb); + if (extra_mutex) + mutex_unlock(extra_mutex); + cb->extack = NULL; } if (nlk->dump_done_errno > 0 || skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) { - mutex_unlock(nlk->cb_mutex); + mutex_unlock(&nlk->nl_cb_mutex); if (sk_filter(sk, skb)) kfree_skb(skb); @@ -2290,13 +2296,13 @@ static int netlink_dump(struct sock *sk, bool lock_taken) WRITE_ONCE(nlk->cb_running, false); module = cb->module; skb = cb->skb; - mutex_unlock(nlk->cb_mutex); + mutex_unlock(&nlk->nl_cb_mutex); module_put(module); consume_skb(skb); return 0; errout_skb: - mutex_unlock(nlk->cb_mutex); + mutex_unlock(&nlk->nl_cb_mutex); kfree_skb(skb); return err; } @@ -2319,7 +2325,7 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, } nlk = nlk_sk(sk); - mutex_lock(nlk->cb_mutex); + mutex_lock(&nlk->nl_cb_mutex); /* A dump is in progress... */ if (nlk->cb_running) { ret = -EBUSY; @@ -2339,6 +2345,7 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, cb->data = control->data; cb->module = control->module; cb->min_dump_alloc = control->min_dump_alloc; + cb->flags = control->flags; cb->skb = skb; cb->strict_check = nlk_test_bit(STRICT_CHK, NETLINK_CB(skb).sk); @@ -2370,7 +2377,7 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, module_put(control->module); error_unlock: sock_put(sk); - mutex_unlock(nlk->cb_mutex); + mutex_unlock(&nlk->nl_cb_mutex); error_free: kfree_skb(skb); return ret; diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h index 9252ad6694a0638a97acdaa1fd30114abfc474fb..b1a17c0d97a103e9f45592df7fe3e25379352e0e 100644 --- a/net/netlink/af_netlink.h +++ b/net/netlink/af_netlink.h @@ -38,8 +38,9 @@ struct netlink_sock { bool cb_running; int dump_done_errno; struct netlink_callback cb; - struct mutex *cb_mutex; - struct mutex cb_def_mutex; + struct mutex nl_cb_mutex; + + struct mutex *dump_cb_mutex; void (*netlink_rcv)(struct sk_buff *skb); int (*netlink_bind)(struct net *net, int group); void (*netlink_unbind)(struct net *net, int group);