linux/net/tipc, branch v4.5

tipc: fix nullptr crash during subscription cancel

2016-03-07T04:00:08Z

commit 4d5cfcba2f6e ('tipc: fix connection abort during subscription cancel'), removes the check for a valid subscription before calling tipc_nametbl_subscribe(). This will lead to a nullptr exception when we process a subscription cancel request. For a cancel request, a null subscription is passed to tipc_nametbl_subscribe() resulting in exception. In this commit, we call tipc_nametbl_subscribe() only for a valid subscription. Fixes: 4d5cfcba2f6e ('tipc: fix connection abort during subscription cancel') Reported-by: Anders Widell Signed-off-by: Parthasarathy Bhuvaragan Acked-by: Jon Maloy Signed-off-by: David S. Miller

tipc: Revert "tipc: use existing sk_write_queue for outgoing packet chain"

2016-03-03T21:30:29Z

reverts commit 94153e36e709e ("tipc: use existing sk_write_queue for outgoing packet chain") In Commit 94153e36e709e, we assume that we fill & empty the socket's sk_write_queue within the same lock_sock() session. This is not true if the link is congested. During congestion, the socket lock is released while we wait for the congestion to cease. This implementation causes a nullptr exception, if the user space program has several threads accessing the same socket descriptor. Consider two threads of the same program performing the following: Thread1 Thread2 -------------------- ---------------------- Enter tipc_sendmsg() Enter tipc_sendmsg() lock_sock() lock_sock() Enter tipc_link_xmit(), ret=ELINKCONG spin on socket lock.. sk_wait_event() : release_sock() grab socket lock : Enter tipc_link_xmit(), ret=0 : release_sock() Wakeup after congestion lock_sock() skb = skb_peek(pktchain); !! TIPC_SKB_CB(skb)->wakeup_pending = tsk->link_cong; In this case, the second thread transmits the buffers belonging to both thread1 and thread2 successfully. When the first thread wakeup after the congestion it assumes that the pktchain is intact and operates on the skb's in it, which leads to the following exception: [2102.439969] BUG: unable to handle kernel NULL pointer dereference at 00000000000000d0 [2102.440074] IP: [] __tipc_link_xmit+0x2b0/0x4d0 [tipc] [2102.440074] PGD 3fa3f067 PUD 3fa6b067 PMD 0 [2102.440074] Oops: 0000 [#1] SMP [2102.440074] CPU: 2 PID: 244 Comm: sender Not tainted 3.12.28 #1 [2102.440074] RIP: 0010:[] [] __tipc_link_xmit+0x2b0/0x4d0 [tipc] [...] [2102.440074] Call Trace: [2102.440074] [] ? schedule+0x29/0x70 [2102.440074] [] ? tipc_node_unlock+0x46/0x170 [tipc] [2102.440074] [] tipc_link_xmit+0x51/0xf0 [tipc] [2102.440074] [] tipc_send_stream+0x11e/0x4f0 [tipc] [2102.440074] [] ? __wake_up_sync+0x20/0x20 [2102.440074] [] tipc_send_packet+0x1c/0x20 [tipc] [2102.440074] [] sock_sendmsg+0xa8/0xd0 [2102.440074] [] ? release_sock+0x145/0x170 [2102.440074] [] ___sys_sendmsg+0x3d8/0x3e0 [2102.440074] [] ? _raw_spin_unlock+0xe/0x10 [2102.440074] [] ? handle_mm_fault+0x6ca/0x9d0 [2102.440074] [] ? set_next_entity+0x85/0xa0 [2102.440074] [] ? _raw_spin_unlock_irq+0xe/0x20 [2102.440074] [] ? finish_task_switch+0x5c/0xc0 [2102.440074] [] ? __schedule+0x34c/0x950 [2102.440074] [] __sys_sendmsg+0x42/0x80 [2102.440074] [] SyS_sendmsg+0x12/0x20 [2102.440074] [] system_call_fastpath+0x16/0x1b In this commit, we maintain the skb list always in the stack. Signed-off-by: Parthasarathy Bhuvaragan Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: David S. Miller

tipc: unlock in error path

2016-02-19T20:38:44Z

tipc_bcast_unlock need to be unlocked in error path. Signed-off-by: Insu Yun Signed-off-by: David S. Miller

tipc: fix premature addition of node to lookup table

2016-02-16T20:57:11Z

In commit 5266698661401a ("tipc: let broadcast packet reception use new link receive function") we introduced a new per-node broadcast reception link instance. This link is created at the moment the node itself is created. Unfortunately, the allocation is done after the node instance has already been added to the node lookup hash table. This creates a potential race condition, where arriving broadcast packets are able to find and access the node before it has been fully initialized, and before the above mentioned link has been created. The result is occasional crashes in the function tipc_bcast_rcv(), which is trying to access the not-yet existing link. We fix this by deferring the addition of the node instance until after it has been fully initialized in the function tipc_node_create(). Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: fix connection abort during subscription cancel

2016-01-29T20:14:21Z

In 'commit 7fe8097cef5f ("tipc: fix nullpointer bug when subscribing to events")', we terminate the connection if the subscription creation fails. In the same commit, the subscription creation result was based on the value of the subscription pointer (set in the function) instead of the return code. Unfortunately, the same function tipc_subscrp_create() handles subscription cancel request. For a subscription cancellation request, the subscription pointer cannot be set. Thus if a subscriber has several subscriptions and cancels any of them, the connection is terminated. In this commit, we terminate the connection based on the return value of tipc_subscrp_create(). Fixes: commit 7fe8097cef5f ("tipc: fix nullpointer bug when subscribing to events") Reviewed-by: Jon Maloy Signed-off-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller

ip_tunnel: Move stats update to iptunnel_xmit()

2015-12-26T04:32:23Z

By moving stats update into iptunnel_xmit(), we can simplify iptunnel_xmit() usage. With this change there is no need to call another function (iptunnel_xmit_stats()) to update stats in tunnel xmit code path. Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2015-12-04T02:09:12Z

Conflicts: drivers/net/ethernet/renesas/ravb_main.c kernel/bpf/syscall.c net/ipv4/ipmr.c All three conflicts were cases of overlapping changes. Signed-off-by: David S. Miller

tipc: fix node reference count bug

2015-12-03T20:19:40Z

Commit 5405ff6e15f40f2f ("tipc: convert node lock to rwlock") introduced a bug to the node reference counter handling. When a message is successfully sent in the function tipc_node_xmit(), we return directly after releasing the node lock, instead of continuing and decrementing the node reference counter as we should do. This commit fixes this bug. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

net: Generalise wq_has_sleeper helper

2015-11-30T19:47:33Z

The memory barrier in the helper wq_has_sleeper is needed by just about every user of waitqueue_active. This patch generalises it by making it take a wait_queue_head_t directly. The existing helper is renamed to skwq_has_sleeper. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller

tipc: fix error handling of expanding buffer headroom

2015-11-24T16:26:19Z

Coverity says: *** CID 1338065: Error handling issues (CHECKED_RETURN) /net/tipc/udp_media.c: 162 in tipc_udp_send_msg() 156 struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value; 157 struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value; 158 struct sk_buff *clone; 159 struct rtable *rt; 160 161 if (skb_headroom(skb) < UDP_MIN_HEADROOM) >>> CID 1338065: Error handling issues (CHECKED_RETURN) >>> Calling "pskb_expand_head" without checking return value (as is done elsewhere 51 out of 56 times). 162 pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC); 163 164 clone = skb_clone(skb, GFP_ATOMIC); 165 skb_set_inner_protocol(clone, htons(ETH_P_TIPC)); 166 ub = rcu_dereference_rtnl(b->media_ptr); 167 if (!ub) { When expanding buffer headroom over udp tunnel with pskb_expand_head(), it's unfortunate that we don't check its return value. As a result, if the function returns an error code due to the lack of memory, it may cause unpredictable consequence as we unconditionally consider that it's always successful. Fixes: e53567948f82 ("tipc: conditionally expand buffer headroom over udp tunnel") Reported-by: Cc: Stephen Hemminger Signed-off-by: Ying Xue Signed-off-by: David S. Miller