From c3317f4db831b7564ff8d1670326456a7fbbbcb3 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Wed, 11 Apr 2018 22:52:09 +0200 Subject: tipc: fix unbalanced reference counter When a topology subscription is created, we may encounter (or KASAN may provoke) a failure to create a corresponding service instance in the binding table. Instead of letting the tipc_nametbl_subscribe() report the failure back to the caller, the function just makes a warning printout and returns, without incrementing the subscription reference counter as expected by the caller. This makes the caller believe that the subscription was successful, so it will at a later moment try to unsubscribe the item. This involves a sub_put() call. Since the reference counter never was incremented in the first place, we get a premature delete of the subscription item, followed by a "use-after-free" warning. We fix this by adding a return value to tipc_nametbl_subscribe() and make the caller aware of the failure to subscribe. This bug seems to always have been around, but this fix only applies back to the commit shown below. Given the low risk of this happening we believe this to be sufficient. Fixes: commit 218527fe27ad ("tipc: replace name table service range array with rb tree") Reported-by: syzbot+aa245f26d42b8305d157@syzkaller.appspotmail.com Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/name_table.c | 5 ++++- net/tipc/name_table.h | 2 +- net/tipc/subscr.c | 5 ++++- 3 files changed, 9 insertions(+), 3 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/name_table.c b/net/tipc/name_table.c index b1fe20972aa9..4068eaad61a6 100644 --- a/net/tipc/name_table.c +++ b/net/tipc/name_table.c @@ -665,13 +665,14 @@ int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower, /** * tipc_nametbl_subscribe - add a subscription object to the name table */ -void tipc_nametbl_subscribe(struct tipc_subscription *sub) +bool tipc_nametbl_subscribe(struct tipc_subscription *sub) { struct name_table *nt = tipc_name_table(sub->net); struct tipc_net *tn = tipc_net(sub->net); struct tipc_subscr *s = &sub->evt.s; u32 type = tipc_sub_read(s, seq.type); struct tipc_service *sc; + bool res = true; spin_lock_bh(&tn->nametbl_lock); sc = tipc_service_find(sub->net, type); @@ -685,8 +686,10 @@ void tipc_nametbl_subscribe(struct tipc_subscription *sub) pr_warn("Failed to subscribe for {%u,%u,%u}\n", type, tipc_sub_read(s, seq.lower), tipc_sub_read(s, seq.upper)); + res = false; } spin_unlock_bh(&tn->nametbl_lock); + return res; } /** diff --git a/net/tipc/name_table.h b/net/tipc/name_table.h index 4b14fc28d9e2..0febba41da86 100644 --- a/net/tipc/name_table.h +++ b/net/tipc/name_table.h @@ -126,7 +126,7 @@ struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type, struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type, u32 lower, u32 upper, u32 node, u32 key); -void tipc_nametbl_subscribe(struct tipc_subscription *s); +bool tipc_nametbl_subscribe(struct tipc_subscription *s); void tipc_nametbl_unsubscribe(struct tipc_subscription *s); int tipc_nametbl_init(struct net *net); void tipc_nametbl_stop(struct net *net); diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c index b7d80bc5f4ab..f340e53da625 100644 --- a/net/tipc/subscr.c +++ b/net/tipc/subscr.c @@ -153,7 +153,10 @@ struct tipc_subscription *tipc_sub_subscribe(struct net *net, memcpy(&sub->evt.s, s, sizeof(*s)); spin_lock_init(&sub->lock); kref_init(&sub->kref); - tipc_nametbl_subscribe(sub); + if (!tipc_nametbl_subscribe(sub)) { + kfree(sub); + return NULL; + } timer_setup(&sub->timer, tipc_sub_timeout, 0); timeout = tipc_sub_read(&sub->evt.s, timeout); if (timeout != TIPC_WAIT_FOREVER) -- cgit v1.2.3 From 335b929b28aeb5bfc0698adb21deaf685b2982d1 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Thu, 12 Apr 2018 01:15:48 +0200 Subject: tipc: fix missing initializer in tipc_sendmsg() The stack variable 'dnode' in __tipc_sendmsg() may theoretically end up tipc_node_get_mtu() as an unitilalized variable. We fix this by intializing the variable at declaration. We also add a default else clause to the two conditional ones already there, so that we never end up in the named function if the given address type is illegal. Reported-by: syzbot+b0975ce9355b347c1546@syzkaller.appspotmail.com Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/socket.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/tipc') diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 1fd1c8b5ce03..252a52ae0893 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1278,7 +1278,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen) struct tipc_msg *hdr = &tsk->phdr; struct tipc_name_seq *seq; struct sk_buff_head pkts; - u32 dnode, dport; + u32 dport, dnode = 0; u32 type, inst; int mtu, rc; @@ -1348,6 +1348,8 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen) msg_set_destnode(hdr, dnode); msg_set_destport(hdr, dest->addr.id.ref); msg_set_hdr_sz(hdr, BASIC_H_SIZE); + } else { + return -EINVAL; } /* Block or return if destination link is congested */ -- cgit v1.2.3 From ec518f21cb1a1b1f8a516499ea05c60299e04963 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 16 Apr 2018 08:29:42 -0700 Subject: tipc: add policy for TIPC_NLA_NET_ADDR Before syzbot/KMSAN bites, add the missing policy for TIPC_NLA_NET_ADDR Fixes: 27c21416727a ("tipc: add net set to new netlink api") Signed-off-by: Eric Dumazet Cc: Jon Maloy Cc: Ying Xue Signed-off-by: David S. Miller --- net/tipc/netlink.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/tipc') diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c index b76f13f6fea1..d4e0bbeee727 100644 --- a/net/tipc/netlink.c +++ b/net/tipc/netlink.c @@ -79,7 +79,8 @@ const struct nla_policy tipc_nl_sock_policy[TIPC_NLA_SOCK_MAX + 1] = { const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = { [TIPC_NLA_NET_UNSPEC] = { .type = NLA_UNSPEC }, - [TIPC_NLA_NET_ID] = { .type = NLA_U32 } + [TIPC_NLA_NET_ID] = { .type = NLA_U32 }, + [TIPC_NLA_NET_ADDR] = { .type = NLA_U32 }, }; const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = { -- cgit v1.2.3 From c6404122cb18f1fbd2a6dc85ab687f6fa2e454cf Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 16 Apr 2018 08:29:43 -0700 Subject: tipc: fix possible crash in __tipc_nl_net_set() syzbot reported a crash in __tipc_nl_net_set() caused by NULL dereference. We need to check that both TIPC_NLA_NET_NODEID and TIPC_NLA_NET_NODEID_W1 are present. We also need to make sure userland provided u64 attributes. Fixes: d50ccc2d3909 ("tipc: add 128-bit node identifier") Signed-off-by: Eric Dumazet Cc: Jon Maloy Cc: Ying Xue Reported-by: syzbot Signed-off-by: David S. Miller --- net/tipc/net.c | 2 ++ net/tipc/netlink.c | 2 ++ 2 files changed, 4 insertions(+) (limited to 'net/tipc') diff --git a/net/tipc/net.c b/net/tipc/net.c index 856f9e97ea29..4fbaa0464405 100644 --- a/net/tipc/net.c +++ b/net/tipc/net.c @@ -252,6 +252,8 @@ int __tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info) u64 *w0 = (u64 *)&node_id[0]; u64 *w1 = (u64 *)&node_id[8]; + if (!attrs[TIPC_NLA_NET_NODEID_W1]) + return -EINVAL; *w0 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID]); *w1 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID_W1]); tipc_net_init(net, node_id, 0); diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c index d4e0bbeee727..6ff2254088f6 100644 --- a/net/tipc/netlink.c +++ b/net/tipc/netlink.c @@ -81,6 +81,8 @@ const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = { [TIPC_NLA_NET_UNSPEC] = { .type = NLA_UNSPEC }, [TIPC_NLA_NET_ID] = { .type = NLA_U32 }, [TIPC_NLA_NET_ADDR] = { .type = NLA_U32 }, + [TIPC_NLA_NET_NODEID] = { .type = NLA_U64 }, + [TIPC_NLA_NET_NODEID_W1] = { .type = NLA_U64 }, }; const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = { -- cgit v1.2.3 From be47e41d77fba5bc17e9fb5f1c99217bb6691989 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Tue, 17 Apr 2018 21:25:42 +0200 Subject: tipc: fix use-after-free in tipc_nametbl_stop When we delete a service item in tipc_nametbl_stop() we loop over all service ranges in the service's RB tree, and for each service range we loop over its pertaining publications while calling tipc_service_remove_publ() for each of them. However, tipc_service_remove_publ() has the side effect that it also removes the comprising service range item when there are no publications left. This leads to a "use-after-free" access when the inner loop continues to the next iteration, since the range item holding the list we are looping no longer exists. We fix this by moving the delete of the service range item outside the said function. Instead, we now let the two functions calling it test if the list is empty and perform the removal when that is the case. Reported-by: syzbot+d64b64afc55660106556@syzkaller.appspotmail.com Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/name_table.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/name_table.c b/net/tipc/name_table.c index 4068eaad61a6..dd1c4fa2eb78 100644 --- a/net/tipc/name_table.c +++ b/net/tipc/name_table.c @@ -241,7 +241,8 @@ err: static struct publication *tipc_service_remove_publ(struct net *net, struct tipc_service *sc, u32 lower, u32 upper, - u32 node, u32 key) + u32 node, u32 key, + struct service_range **rng) { struct tipc_subscription *sub, *tmp; struct service_range *sr; @@ -275,19 +276,15 @@ static struct publication *tipc_service_remove_publ(struct net *net, list_del(&p->all_publ); list_del(&p->local_publ); - - /* Remove service range item if this was its last publication */ - if (list_empty(&sr->all_publ)) { + if (list_empty(&sr->all_publ)) last = true; - rb_erase(&sr->tree_node, &sc->ranges); - kfree(sr); - } /* Notify any waiting subscriptions */ list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) { tipc_sub_report_overlap(sub, p->lower, p->upper, TIPC_WITHDRAWN, p->port, p->node, p->scope, last); } + *rng = sr; return p; } @@ -379,13 +376,20 @@ struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type, u32 node, u32 key) { struct tipc_service *sc = tipc_service_find(net, type); + struct service_range *sr = NULL; struct publication *p = NULL; if (!sc) return NULL; spin_lock_bh(&sc->lock); - p = tipc_service_remove_publ(net, sc, lower, upper, node, key); + p = tipc_service_remove_publ(net, sc, lower, upper, node, key, &sr); + + /* Remove service range item if this was its last publication */ + if (sr && list_empty(&sr->all_publ)) { + rb_erase(&sr->tree_node, &sc->ranges); + kfree(sr); + } /* Delete service item if this no more publications and subscriptions */ if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) { @@ -747,16 +751,17 @@ int tipc_nametbl_init(struct net *net) static void tipc_service_delete(struct net *net, struct tipc_service *sc) { struct service_range *sr, *tmpr; - struct publication *p, *tmpb; + struct publication *p, *tmp; spin_lock_bh(&sc->lock); rbtree_postorder_for_each_entry_safe(sr, tmpr, &sc->ranges, tree_node) { - list_for_each_entry_safe(p, tmpb, - &sr->all_publ, all_publ) { + list_for_each_entry_safe(p, tmp, &sr->all_publ, all_publ) { tipc_service_remove_publ(net, sc, p->lower, p->upper, - p->node, p->key); + p->node, p->key, &sr); kfree_rcu(p, rcu); } + rb_erase(&sr->tree_node, &sc->ranges); + kfree(sr); } hlist_del_init_rcu(&sc->service_list); spin_unlock_bh(&sc->lock); -- cgit v1.2.3 From 36a50a989ee8267588de520b8704b85f045a3220 Mon Sep 17 00:00:00 2001 From: Tung Nguyen Date: Tue, 17 Apr 2018 21:58:27 +0200 Subject: tipc: fix infinite loop when dumping link monitor summary When configuring the number of used bearers to MAX_BEARER and issuing command "tipc link monitor summary", the command enters infinite loop in user space. This issue happens because function tipc_nl_node_dump_monitor() returns the wrong 'prev_bearer' value when all potential monitors have been scanned. The correct behavior is to always try to scan all monitors until either the netlink message is full, in which case we return the bearer identity of the affected monitor, or we continue through the whole bearer array until we can return MAX_BEARERS. This solution also caters for the case where there may be gaps in the bearer array. Signed-off-by: Tung Nguyen Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/monitor.c | 2 +- net/tipc/node.c | 11 ++++------- 2 files changed, 5 insertions(+), 8 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/monitor.c b/net/tipc/monitor.c index 32dc33a94bc7..5453e564da82 100644 --- a/net/tipc/monitor.c +++ b/net/tipc/monitor.c @@ -777,7 +777,7 @@ int __tipc_nl_add_monitor(struct net *net, struct tipc_nl_msg *msg, ret = tipc_bearer_get_name(net, bearer_name, bearer_id); if (ret || !mon) - return -EINVAL; + return 0; hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, NLM_F_MULTI, TIPC_NL_MON_GET); diff --git a/net/tipc/node.c b/net/tipc/node.c index c77dd2f3c589..6f98b56dd48e 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -2232,8 +2232,8 @@ int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb) struct net *net = sock_net(skb->sk); u32 prev_bearer = cb->args[0]; struct tipc_nl_msg msg; + int bearer_id; int err; - int i; if (prev_bearer == MAX_BEARERS) return 0; @@ -2243,16 +2243,13 @@ int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb) msg.seq = cb->nlh->nlmsg_seq; rtnl_lock(); - for (i = prev_bearer; i < MAX_BEARERS; i++) { - prev_bearer = i; + for (bearer_id = prev_bearer; bearer_id < MAX_BEARERS; bearer_id++) { err = __tipc_nl_add_monitor(net, &msg, prev_bearer); if (err) - goto out; + break; } - -out: rtnl_unlock(); - cb->args[0] = prev_bearer; + cb->args[0] = bearer_id; return skb->len; } -- cgit v1.2.3