From: Jakub Kicinski <kuba@kernel.org>
To: Hoang Huu Le <hoang.h.le@dektech.com.au>
Cc: jmaloy@redhat.com, maloy@donjonn.com, ying.xue@windriver.com,
tipc-discussion@lists.sourceforge.net, netdev@vger.kernel.org
Subject: Re: [net] tipc: fix NULL pointer dereference in tipc_named_rcv
Date: Thu, 8 Oct 2020 10:25:14 -0700 [thread overview]
Message-ID: <20201008102514.1184c315@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> (raw)
In-Reply-To: <20201008073156.116136-1-hoang.h.le@dektech.com.au>
On Thu, 8 Oct 2020 14:31:56 +0700 Hoang Huu Le wrote:
> diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c
> index 2f9c148f17e2..fe4edce459ad 100644
> --- a/net/tipc/name_distr.c
> +++ b/net/tipc/name_distr.c
> @@ -327,8 +327,13 @@ static struct sk_buff *tipc_named_dequeue(struct sk_buff_head *namedq,
> struct tipc_msg *hdr;
> u16 seqno;
>
> + spin_lock_bh(&namedq->lock);
> skb_queue_walk_safe(namedq, skb, tmp) {
> - skb_linearize(skb);
> + if (unlikely(skb_linearize(skb))) {
> + __skb_unlink(skb, namedq);
> + kfree_skb(skb);
> + continue;
> + }
> hdr = buf_msg(skb);
> seqno = msg_named_seqno(hdr);
> if (msg_is_last_bulk(hdr)) {
> @@ -338,12 +343,14 @@ static struct sk_buff *tipc_named_dequeue(struct sk_buff_head *namedq,
>
> if (msg_is_bulk(hdr) || msg_is_legacy(hdr)) {
> __skb_unlink(skb, namedq);
> + spin_unlock_bh(&namedq->lock);
> return skb;
> }
>
> if (*open && (*rcv_nxt == seqno)) {
> (*rcv_nxt)++;
> __skb_unlink(skb, namedq);
> + spin_unlock_bh(&namedq->lock);
> return skb;
> }
>
> @@ -353,6 +360,7 @@ static struct sk_buff *tipc_named_dequeue(struct sk_buff_head *namedq,
> continue;
> }
> }
> + spin_unlock_bh(&namedq->lock);
> return NULL;
> }
>
> diff --git a/net/tipc/node.c b/net/tipc/node.c
> index cf4b239fc569..d269ebe382e1 100644
> --- a/net/tipc/node.c
> +++ b/net/tipc/node.c
> @@ -1496,7 +1496,7 @@ static void node_lost_contact(struct tipc_node *n,
>
> /* Clean up broadcast state */
> tipc_bcast_remove_peer(n->net, n->bc_entry.link);
> - __skb_queue_purge(&n->bc_entry.namedq);
> + skb_queue_purge(&n->bc_entry.namedq);
Patch looks fine, but I'm not sure why not hold
spin_unlock_bh(&tn->nametbl_lock) here instead?
Seems like node_lost_contact() should be relatively rare,
so adding another lock to tipc_named_dequeue() is not the
right trade off.
> /* Abort any ongoing link failover */
> for (i = 0; i < MAX_BEARERS; i++) {
next prev parent reply other threads:[~2020-10-08 17:25 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-08 7:31 [net] tipc: fix NULL pointer dereference in tipc_named_rcv Hoang Huu Le
2020-10-08 17:25 ` Jakub Kicinski [this message]
2020-10-08 18:00 ` Jon Maloy
2020-10-09 4:12 ` Hoang Huu Le
2020-10-09 12:47 ` Jon Maloy
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