From 7ab412d33b4c7ff3e0148d3db25dd861edd1283d Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Sat, 10 Nov 2018 17:30:24 -0500 Subject: tipc: fix link re-establish failure When a link failure is detected locally, the link is reset, the flag link->in_session is set to false, and a RESET_MSG with the 'stopping' bit set is sent to the peer. The purpose of this bit is to inform the peer that this endpoint just is going down, and that the peer should handle the reception of this particular RESET message as a local failure. This forces the peer to accept another RESET or ACTIVATE message from this endpoint before it can re-establish the link. This again is necessary to ensure that link session numbers are properly exchanged before the link comes up again. If a failure is detected locally at the same time at the peer endpoint this will do the same, which is also a correct behavior. However, when receiving such messages, the endpoints will not distinguish between 'stopping' RESETs and ordinary ones when it comes to updating session numbers. Both endpoints will copy the received session number and set their 'in_session' flags to true at the reception, while they are still expecting another RESET from the peer before they can go ahead and re-establish. This is contradictory, since, after applying the validation check referred to below, the 'in_session' flag will cause rejection of all such messages, and the link will never come up again. We now fix this by not only handling received RESET/STOPPING messages as a local failure, but also by omitting to set a new session number and the 'in_session' flag in such cases. Fixes: 7ea817f4e832 ("tipc: check session number before accepting link protocol messages") Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/link.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/link.c b/net/tipc/link.c index 201c3b5bc96b..836727e363c4 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -1594,14 +1594,17 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb, if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI)) l->priority = peers_prio; - /* ACTIVATE_MSG serves as PEER_RESET if link is already down */ - if (msg_peer_stopping(hdr)) + /* If peer is going down we want full re-establish cycle */ + if (msg_peer_stopping(hdr)) { rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT); - else if ((mtyp == RESET_MSG) || !link_is_up(l)) + break; + } + /* ACTIVATE_MSG serves as PEER_RESET if link is already down */ + if (mtyp == RESET_MSG || !link_is_up(l)) rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT); /* ACTIVATE_MSG takes up link if it was already locally reset */ - if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING)) + if (mtyp == ACTIVATE_MSG && l->state == LINK_ESTABLISHING) rc = TIPC_LINK_UP_EVT; l->peer_session = msg_session(hdr); -- cgit From adba75be0d23cca92a028749d92c60c8909bbdb3 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Fri, 16 Nov 2018 16:55:04 -0500 Subject: tipc: fix lockdep warning when reinitilaizing sockets We get the following warning: [ 47.926140] 32-bit node address hash set to 2010a0a [ 47.927202] [ 47.927433] ================================ [ 47.928050] WARNING: inconsistent lock state [ 47.928661] 4.19.0+ #37 Tainted: G E [ 47.929346] -------------------------------- [ 47.929954] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. [ 47.930116] swapper/3/0 [HC0[0]:SC1[3]:HE1:SE0] takes: [ 47.930116] 00000000af8bc31e (&(&ht->lock)->rlock){+.?.}, at: rhashtable_walk_enter+0x36/0xb0 [ 47.930116] {SOFTIRQ-ON-W} state was registered at: [ 47.930116] _raw_spin_lock+0x29/0x60 [ 47.930116] rht_deferred_worker+0x556/0x810 [ 47.930116] process_one_work+0x1f5/0x540 [ 47.930116] worker_thread+0x64/0x3e0 [ 47.930116] kthread+0x112/0x150 [ 47.930116] ret_from_fork+0x3a/0x50 [ 47.930116] irq event stamp: 14044 [ 47.930116] hardirqs last enabled at (14044): [] __local_bh_enable_ip+0x7a/0xf0 [ 47.938117] hardirqs last disabled at (14043): [] __local_bh_enable_ip+0x41/0xf0 [ 47.938117] softirqs last enabled at (14028): [] irq_enter+0x5e/0x60 [ 47.938117] softirqs last disabled at (14029): [] irq_exit+0xb5/0xc0 [ 47.938117] [ 47.938117] other info that might help us debug this: [ 47.938117] Possible unsafe locking scenario: [ 47.938117] [ 47.938117] CPU0 [ 47.938117] ---- [ 47.938117] lock(&(&ht->lock)->rlock); [ 47.938117] [ 47.938117] lock(&(&ht->lock)->rlock); [ 47.938117] [ 47.938117] *** DEADLOCK *** [ 47.938117] [ 47.938117] 2 locks held by swapper/3/0: [ 47.938117] #0: 0000000062c64f90 ((&d->timer)){+.-.}, at: call_timer_fn+0x5/0x280 [ 47.938117] #1: 00000000ee39619c (&(&d->lock)->rlock){+.-.}, at: tipc_disc_timeout+0xc8/0x540 [tipc] [ 47.938117] [ 47.938117] stack backtrace: [ 47.938117] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G E 4.19.0+ #37 [ 47.938117] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 47.938117] Call Trace: [ 47.938117] [ 47.938117] dump_stack+0x5e/0x8b [ 47.938117] print_usage_bug+0x1ed/0x1ff [ 47.938117] mark_lock+0x5b5/0x630 [ 47.938117] __lock_acquire+0x4c0/0x18f0 [ 47.938117] ? lock_acquire+0xa6/0x180 [ 47.938117] lock_acquire+0xa6/0x180 [ 47.938117] ? rhashtable_walk_enter+0x36/0xb0 [ 47.938117] _raw_spin_lock+0x29/0x60 [ 47.938117] ? rhashtable_walk_enter+0x36/0xb0 [ 47.938117] rhashtable_walk_enter+0x36/0xb0 [ 47.938117] tipc_sk_reinit+0xb0/0x410 [tipc] [ 47.938117] ? mark_held_locks+0x6f/0x90 [ 47.938117] ? __local_bh_enable_ip+0x7a/0xf0 [ 47.938117] ? lockdep_hardirqs_on+0x20/0x1a0 [ 47.938117] tipc_net_finalize+0xbf/0x180 [tipc] [ 47.938117] tipc_disc_timeout+0x509/0x540 [tipc] [ 47.938117] ? call_timer_fn+0x5/0x280 [ 47.938117] ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc] [ 47.938117] ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc] [ 47.938117] call_timer_fn+0xa1/0x280 [ 47.938117] ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc] [ 47.938117] run_timer_softirq+0x1f2/0x4d0 [ 47.938117] __do_softirq+0xfc/0x413 [ 47.938117] irq_exit+0xb5/0xc0 [ 47.938117] smp_apic_timer_interrupt+0xac/0x210 [ 47.938117] apic_timer_interrupt+0xf/0x20 [ 47.938117] [ 47.938117] RIP: 0010:default_idle+0x1c/0x140 [ 47.938117] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 41 54 55 53 65 8b 2d d8 2b 74 65 0f 1f 44 00 00 e8 c6 2c 8b ff fb f4 <65> 8b 2d c5 2b 74 65 0f 1f 44 00 00 5b 5d 41 5c c3 65 8b 05 b4 2b [ 47.938117] RSP: 0018:ffffaf6ac0207ec8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 [ 47.938117] RAX: ffff8f5b3735e200 RBX: 0000000000000003 RCX: 0000000000000001 [ 47.938117] RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8f5b3735e200 [ 47.938117] RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000000 [ 47.938117] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 47.938117] R13: 0000000000000000 R14: ffff8f5b3735e200 R15: ffff8f5b3735e200 [ 47.938117] ? default_idle+0x1a/0x140 [ 47.938117] do_idle+0x1bc/0x280 [ 47.938117] cpu_startup_entry+0x19/0x20 [ 47.938117] start_secondary+0x187/0x1c0 [ 47.938117] secondary_startup_64+0xa4/0xb0 The reason seems to be that tipc_net_finalize()->tipc_sk_reinit() is calling the function rhashtable_walk_enter() within a timer interrupt. We fix this by executing tipc_net_finalize() in work queue context. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/discover.c | 19 ++++++++++--------- net/tipc/net.c | 45 +++++++++++++++++++++++++++++++++++++-------- net/tipc/net.h | 2 +- 3 files changed, 48 insertions(+), 18 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/discover.c b/net/tipc/discover.c index 2830709957bd..c138d68e8a69 100644 --- a/net/tipc/discover.c +++ b/net/tipc/discover.c @@ -166,7 +166,8 @@ static bool tipc_disc_addr_trial_msg(struct tipc_discoverer *d, /* Apply trial address if we just left trial period */ if (!trial && !self) { - tipc_net_finalize(net, tn->trial_addr); + tipc_sched_net_finalize(net, tn->trial_addr); + msg_set_prevnode(buf_msg(d->skb), tn->trial_addr); msg_set_type(buf_msg(d->skb), DSC_REQ_MSG); } @@ -300,14 +301,12 @@ static void tipc_disc_timeout(struct timer_list *t) goto exit; } - /* Trial period over ? */ - if (!time_before(jiffies, tn->addr_trial_end)) { - /* Did we just leave it ? */ - if (!tipc_own_addr(net)) - tipc_net_finalize(net, tn->trial_addr); - - msg_set_type(buf_msg(d->skb), DSC_REQ_MSG); - msg_set_prevnode(buf_msg(d->skb), tipc_own_addr(net)); + /* Did we just leave trial period ? */ + if (!time_before(jiffies, tn->addr_trial_end) && !tipc_own_addr(net)) { + mod_timer(&d->timer, jiffies + TIPC_DISC_INIT); + spin_unlock_bh(&d->lock); + tipc_sched_net_finalize(net, tn->trial_addr); + return; } /* Adjust timeout interval according to discovery phase */ @@ -319,6 +318,8 @@ static void tipc_disc_timeout(struct timer_list *t) d->timer_intv = TIPC_DISC_SLOW; else if (!d->num_nodes && d->timer_intv > TIPC_DISC_FAST) d->timer_intv = TIPC_DISC_FAST; + msg_set_type(buf_msg(d->skb), DSC_REQ_MSG); + msg_set_prevnode(buf_msg(d->skb), tn->trial_addr); } mod_timer(&d->timer, jiffies + d->timer_intv); diff --git a/net/tipc/net.c b/net/tipc/net.c index 62199cf5a56c..f076edb74338 100644 --- a/net/tipc/net.c +++ b/net/tipc/net.c @@ -104,6 +104,14 @@ * - A local spin_lock protecting the queue of subscriber events. */ +struct tipc_net_work { + struct work_struct work; + struct net *net; + u32 addr; +}; + +static void tipc_net_finalize(struct net *net, u32 addr); + int tipc_net_init(struct net *net, u8 *node_id, u32 addr) { if (tipc_own_id(net)) { @@ -119,17 +127,38 @@ int tipc_net_init(struct net *net, u8 *node_id, u32 addr) return 0; } -void tipc_net_finalize(struct net *net, u32 addr) +static void tipc_net_finalize(struct net *net, u32 addr) { struct tipc_net *tn = tipc_net(net); - if (!cmpxchg(&tn->node_addr, 0, addr)) { - tipc_set_node_addr(net, addr); - tipc_named_reinit(net); - tipc_sk_reinit(net); - tipc_nametbl_publish(net, TIPC_CFG_SRV, addr, addr, - TIPC_CLUSTER_SCOPE, 0, addr); - } + if (cmpxchg(&tn->node_addr, 0, addr)) + return; + tipc_set_node_addr(net, addr); + tipc_named_reinit(net); + tipc_sk_reinit(net); + tipc_nametbl_publish(net, TIPC_CFG_SRV, addr, addr, + TIPC_CLUSTER_SCOPE, 0, addr); +} + +static void tipc_net_finalize_work(struct work_struct *work) +{ + struct tipc_net_work *fwork; + + fwork = container_of(work, struct tipc_net_work, work); + tipc_net_finalize(fwork->net, fwork->addr); + kfree(fwork); +} + +void tipc_sched_net_finalize(struct net *net, u32 addr) +{ + struct tipc_net_work *fwork = kzalloc(sizeof(*fwork), GFP_ATOMIC); + + if (!fwork) + return; + INIT_WORK(&fwork->work, tipc_net_finalize_work); + fwork->net = net; + fwork->addr = addr; + schedule_work(&fwork->work); } void tipc_net_stop(struct net *net) diff --git a/net/tipc/net.h b/net/tipc/net.h index 09ad02b50bb1..b7f2e364eb99 100644 --- a/net/tipc/net.h +++ b/net/tipc/net.h @@ -42,7 +42,7 @@ extern const struct nla_policy tipc_nl_net_policy[]; int tipc_net_init(struct net *net, u8 *node_id, u32 addr); -void tipc_net_finalize(struct net *net, u32 addr); +void tipc_sched_net_finalize(struct net *net, u32 addr); void tipc_net_stop(struct net *net); int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb); int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info); -- cgit From 1c1274a56999fbdf9cf84e332b28448bb2d55221 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Sat, 17 Nov 2018 12:17:06 -0500 Subject: tipc: don't assume linear buffer when reading ancillary data The code for reading ancillary data from a received buffer is assuming the buffer is linear. To make this assumption true we have to linearize the buffer before message data is read. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/socket.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 636e6131769d..b57b1be7252b 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1555,16 +1555,17 @@ static void tipc_sk_set_orig_addr(struct msghdr *m, struct sk_buff *skb) /** * tipc_sk_anc_data_recv - optionally capture ancillary data for received message * @m: descriptor for message info - * @msg: received message header + * @skb: received message buffer * @tsk: TIPC port associated with message * * Note: Ancillary data is not captured if not requested by receiver. * * Returns 0 if successful, otherwise errno */ -static int tipc_sk_anc_data_recv(struct msghdr *m, struct tipc_msg *msg, +static int tipc_sk_anc_data_recv(struct msghdr *m, struct sk_buff *skb, struct tipc_sock *tsk) { + struct tipc_msg *msg; u32 anc_data[3]; u32 err; u32 dest_type; @@ -1573,6 +1574,7 @@ static int tipc_sk_anc_data_recv(struct msghdr *m, struct tipc_msg *msg, if (likely(m->msg_controllen == 0)) return 0; + msg = buf_msg(skb); /* Optionally capture errored message object(s) */ err = msg ? msg_errcode(msg) : 0; @@ -1583,6 +1585,9 @@ static int tipc_sk_anc_data_recv(struct msghdr *m, struct tipc_msg *msg, if (res) return res; if (anc_data[1]) { + if (skb_linearize(skb)) + return -ENOMEM; + msg = buf_msg(skb); res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1], msg_data(msg)); if (res) @@ -1744,9 +1749,10 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m, /* Collect msg meta data, including error code and rejected data */ tipc_sk_set_orig_addr(m, skb); - rc = tipc_sk_anc_data_recv(m, hdr, tsk); + rc = tipc_sk_anc_data_recv(m, skb, tsk); if (unlikely(rc)) goto exit; + hdr = buf_msg(skb); /* Capture data if non-error msg, otherwise just set return value */ if (likely(!err)) { @@ -1856,9 +1862,10 @@ static int tipc_recvstream(struct socket *sock, struct msghdr *m, /* Collect msg meta data, incl. error code and rejected data */ if (!copied) { tipc_sk_set_orig_addr(m, skb); - rc = tipc_sk_anc_data_recv(m, hdr, tsk); + rc = tipc_sk_anc_data_recv(m, skb, tsk); if (rc) break; + hdr = buf_msg(skb); } /* Copy data if msg ok, otherwise return error/partial data */ -- cgit From ec835f891232d7763dea9da0358f31e24ca6dfb7 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Mon, 26 Nov 2018 12:26:14 -0500 Subject: tipc: fix lockdep warning during node delete We see the following lockdep warning: [ 2284.078521] ====================================================== [ 2284.078604] WARNING: possible circular locking dependency detected [ 2284.078604] 4.19.0+ #42 Tainted: G E [ 2284.078604] ------------------------------------------------------ [ 2284.078604] rmmod/254 is trying to acquire lock: [ 2284.078604] 00000000acd94e28 ((&n->timer)#2){+.-.}, at: del_timer_sync+0x5/0xa0 [ 2284.078604] [ 2284.078604] but task is already holding lock: [ 2284.078604] 00000000f997afc0 (&(&tn->node_list_lock)->rlock){+.-.}, at: tipc_node_stop+0xac/0x190 [tipc] [ 2284.078604] [ 2284.078604] which lock already depends on the new lock. [ 2284.078604] [ 2284.078604] [ 2284.078604] the existing dependency chain (in reverse order) is: [ 2284.078604] [ 2284.078604] -> #1 (&(&tn->node_list_lock)->rlock){+.-.}: [ 2284.078604] tipc_node_timeout+0x20a/0x330 [tipc] [ 2284.078604] call_timer_fn+0xa1/0x280 [ 2284.078604] run_timer_softirq+0x1f2/0x4d0 [ 2284.078604] __do_softirq+0xfc/0x413 [ 2284.078604] irq_exit+0xb5/0xc0 [ 2284.078604] smp_apic_timer_interrupt+0xac/0x210 [ 2284.078604] apic_timer_interrupt+0xf/0x20 [ 2284.078604] default_idle+0x1c/0x140 [ 2284.078604] do_idle+0x1bc/0x280 [ 2284.078604] cpu_startup_entry+0x19/0x20 [ 2284.078604] start_secondary+0x187/0x1c0 [ 2284.078604] secondary_startup_64+0xa4/0xb0 [ 2284.078604] [ 2284.078604] -> #0 ((&n->timer)#2){+.-.}: [ 2284.078604] del_timer_sync+0x34/0xa0 [ 2284.078604] tipc_node_delete+0x1a/0x40 [tipc] [ 2284.078604] tipc_node_stop+0xcb/0x190 [tipc] [ 2284.078604] tipc_net_stop+0x154/0x170 [tipc] [ 2284.078604] tipc_exit_net+0x16/0x30 [tipc] [ 2284.078604] ops_exit_list.isra.8+0x36/0x70 [ 2284.078604] unregister_pernet_operations+0x87/0xd0 [ 2284.078604] unregister_pernet_subsys+0x1d/0x30 [ 2284.078604] tipc_exit+0x11/0x6f2 [tipc] [ 2284.078604] __x64_sys_delete_module+0x1df/0x240 [ 2284.078604] do_syscall_64+0x66/0x460 [ 2284.078604] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 2284.078604] [ 2284.078604] other info that might help us debug this: [ 2284.078604] [ 2284.078604] Possible unsafe locking scenario: [ 2284.078604] [ 2284.078604] CPU0 CPU1 [ 2284.078604] ---- ---- [ 2284.078604] lock(&(&tn->node_list_lock)->rlock); [ 2284.078604] lock((&n->timer)#2); [ 2284.078604] lock(&(&tn->node_list_lock)->rlock); [ 2284.078604] lock((&n->timer)#2); [ 2284.078604] [ 2284.078604] *** DEADLOCK *** [ 2284.078604] [ 2284.078604] 3 locks held by rmmod/254: [ 2284.078604] #0: 000000003368be9b (pernet_ops_rwsem){+.+.}, at: unregister_pernet_subsys+0x15/0x30 [ 2284.078604] #1: 0000000046ed9c86 (rtnl_mutex){+.+.}, at: tipc_net_stop+0x144/0x170 [tipc] [ 2284.078604] #2: 00000000f997afc0 (&(&tn->node_list_lock)->rlock){+.-.}, at: tipc_node_stop+0xac/0x19 [...} The reason is that the node timer handler sometimes needs to delete a node which has been disconnected for too long. To do this, it grabs the lock 'node_list_lock', which may at the same time be held by the generic node cleanup function, tipc_node_stop(), during module removal. Since the latter is calling del_timer_sync() inside the same lock, we have a potential deadlock. We fix this letting the timer cleanup function use spin_trylock() instead of just spin_lock(), and when it fails to grab the lock it just returns so that the timer handler can terminate its execution. This is safe to do, since tipc_node_stop() anyway is about to delete both the timer and the node instance. Fixes: 6a939f365bdb ("tipc: Auto removal of peer down node instance") Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/node.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/node.c b/net/tipc/node.c index 2afc4f8c37a7..488019766433 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -584,12 +584,15 @@ static void tipc_node_clear_links(struct tipc_node *node) /* tipc_node_cleanup - delete nodes that does not * have active links for NODE_CLEANUP_AFTER time */ -static int tipc_node_cleanup(struct tipc_node *peer) +static bool tipc_node_cleanup(struct tipc_node *peer) { struct tipc_net *tn = tipc_net(peer->net); bool deleted = false; - spin_lock_bh(&tn->node_list_lock); + /* If lock held by tipc_node_stop() the node will be deleted anyway */ + if (!spin_trylock_bh(&tn->node_list_lock)) + return false; + tipc_node_write_lock(peer); if (!node_is_up(peer) && time_after(jiffies, peer->delete_at)) { -- cgit