[PATCH net] tipc: purge deferredq list for each grp member in tipc_group_delete

[PATCH net] tipc: purge deferredq list for each grp member in tipc_group_delete

[Xin Long]

Syzbot reported a memleak caused by grp members' deferredq list not
purged when the grp is be deleted.

The issue occurs when more(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt) in
tipc_group_filter_msg() and the skb will stay in deferredq.

So fix it by calling __skb_queue_purge for each member's deferredq
in tipc_group_delete() when a tipc sk leaves the grp.

Fixes: b87a5ea31c93 ("tipc: guarantee group unicast doesn't bypass group broadcast")
Reported-by: syzbot+78fbe679c8ca8d264a8d@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/tipc/group.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/tipc/group.c b/net/tipc/group.c
index 992be61..5f98d38 100644
--- a/net/tipc/group.c
+++ b/net/tipc/group.c
@@ -218,6 +218,7 @@ void tipc_group_delete(struct net *net, struct tipc_group *grp)
 
 	rbtree_postorder_for_each_entry_safe(m, tmp, tree, tree_node) {
 		tipc_group_proto_xmit(grp, m, GRP_LEAVE_MSG, &xmitq);
+		__skb_queue_purge(&m->deferredq);
 		list_del(&m->list);
 		kfree(m);
 	}
-- 
2.1.0

Re: [PATCH net] tipc: purge deferredq list for each grp member in tipc_group_delete

[Ying Xue]

On 6/16/19 5:24 PM, Xin Long wrote:
> Syzbot reported a memleak caused by grp members' deferredq list not
> purged when the grp is be deleted.
> 
> The issue occurs when more(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt) in
> tipc_group_filter_msg() and the skb will stay in deferredq.
> 
> So fix it by calling __skb_queue_purge for each member's deferredq
> in tipc_group_delete() when a tipc sk leaves the grp.
> 
> Fixes: b87a5ea31c93 ("tipc: guarantee group unicast doesn't bypass group broadcast")
> Reported-by: syzbot+78fbe679c8ca8d264a8d@syzkaller.appspotmail.com
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

Acked-by: Ying Xue <ying.xue@windriver.com>

> ---
>  net/tipc/group.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/tipc/group.c b/net/tipc/group.c
> index 992be61..5f98d38 100644
> --- a/net/tipc/group.c
> +++ b/net/tipc/group.c
> @@ -218,6 +218,7 @@ void tipc_group_delete(struct net *net, struct tipc_group *grp)
>  
>  	rbtree_postorder_for_each_entry_safe(m, tmp, tree, tree_node) {
>  		tipc_group_proto_xmit(grp, m, GRP_LEAVE_MSG, &xmitq);
> +		__skb_queue_purge(&m->deferredq);
>  		list_del(&m->list);
>  		kfree(m);
>  	}
> 

Re: [PATCH net] tipc: purge deferredq list for each grp member in tipc_group_delete

[David Miller]

From: Xin Long <lucien.xin@gmail.com>
Date: Sun, 16 Jun 2019 17:24:07 +0800

> Syzbot reported a memleak caused by grp members' deferredq list not
> purged when the grp is be deleted.
> 
> The issue occurs when more(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt) in
> tipc_group_filter_msg() and the skb will stay in deferredq.
> 
> So fix it by calling __skb_queue_purge for each member's deferredq
> in tipc_group_delete() when a tipc sk leaves the grp.
> 
> Fixes: b87a5ea31c93 ("tipc: guarantee group unicast doesn't bypass group broadcast")
> Reported-by: syzbot+78fbe679c8ca8d264a8d@syzkaller.appspotmail.com
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

Applied, thanks.