[PATCH 1/3] tipc: fix memory leak issue

[Ying Xue]

syzbot found the following memory leak:

[   68.602482][ T7130] kmemleak: 2 new suspected memory leaks (see 
/sys/kernel/debug/kmemleak)
BUG: memory leak
unreferenced object 0xffff88810df83c00 (size 512):
  comm "softirq", pid 0, jiffies 4294942354 (age 19.830s)
  hex dump (first 32 bytes):
    38 1a 0d 0f 81 88 ff ff 38 1a 0d 0f 81 88 ff ff  8.......8.......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000009375ee42>] kmem_cache_alloc_node+0x153/0x2a0
    [<000000004c563922>] __alloc_skb+0x6e/0x210
    [<00000000ec87bfa1>] tipc_buf_acquire+0x2f/0x80
    [<00000000d151ef84>] tipc_msg_create+0x37/0xe0
    [<000000008bb437b0>] tipc_group_create_event+0xb3/0x1b0
    [<00000000947b1d0f>] tipc_group_proto_rcv+0x569/0x640
    [<00000000b75ab039>] tipc_sk_filter_rcv+0x9ac/0xf20
    [<000000000dab7a6c>] tipc_sk_rcv+0x494/0x8a0
    [<00000000023a7ddd>] tipc_node_xmit+0x196/0x1f0
    [<00000000337dd9eb>] tipc_node_distr_xmit+0x7d/0x120
    [<00000000b6375182>] tipc_group_delete+0xe6/0x130
    [<000000000361ba2b>] tipc_sk_leave+0x57/0xb0
    [<000000009df90505>] tipc_release+0x7b/0x5e0
    [<000000009f3189da>] __sock_release+0x4b/0xe0
    [<00000000d3568ee0>] sock_close+0x1b/0x30
    [<00000000266a6215>] __fput+0xed/0x300

Reported-by: syzbot+78fbe679c8ca8d264...@syzkaller.appspotmail.com
Signed-off-by: Hillf Danton <hdan...@sina.com>
Signed-off-by: Ying Xue <ying....@windriver.com>
---
 net/tipc/node.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 7ca0190..d1852fc 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1469,10 +1469,13 @@ int tipc_node_xmit(struct net *net, struct sk_buff_head 
*list,
        spin_unlock_bh(&le->lock);
        tipc_node_read_unlock(n);
 
-       if (unlikely(rc == -ENOBUFS))
+       if (unlikely(rc == -ENOBUFS)) {
                tipc_node_link_down(n, bearer_id, false);
-       else
+               skb_queue_purge(list);
+               skb_queue_purge(&xmitq);
+       } else {
                tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
+       }
 
        tipc_node_put(n);
 
-- 
2.7.4