linux-kernel - [PATCH 4.14 008/107] net: datagram: fix unbounded loop in __skb_try_recv

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190401170046.331227014@linuxfoundation.org>
Date:   Mon,  1 Apr 2019 19:01:23 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Paolo Abeni <pabeni@...hat.com>,
        "David S. Miller" <davem@...emloft.net>,
        Christoph Paasch <cpaasch@...le.com>
Subject: [PATCH 4.14 008/107] net: datagram: fix unbounded loop in __skb_try_recv_datagram()

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Paolo Abeni <pabeni@...hat.com>

[ Upstream commit 0b91bce1ebfc797ff3de60c8f4a1e6219a8a3187 ]

Christoph reported a stall while peeking datagram with an offset when
busy polling is enabled. __skb_try_recv_datagram() uses as the loop
termination condition 'queue empty'. When peeking, the socket
queue can be not empty, even when no additional packets are received.

Address the issue explicitly checking for receive queue changes,
as currently done by __skb_wait_for_more_packets().

Fixes: 2b5cd0dfa384 ("net: Change return type of sk_busy_loop from bool to void")
Reported-and-tested-by: Christoph Paasch <cpaasch@...le.com>
Signed-off-by: Paolo Abeni <pabeni@...hat.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 net/core/datagram.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -281,7 +281,7 @@ struct sk_buff *__skb_try_recv_datagram(
 			break;
 
 		sk_busy_loop(sk, flags & MSG_DONTWAIT);
-	} while (!skb_queue_empty(&sk->sk_receive_queue));
+	} while (sk->sk_receive_queue.prev != *last);
 
 	error = -EAGAIN;