linux-kernel - [ 21/31] RDS: fix rds-ping spinlock recursion

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]

Date:	Thu, 25 Oct 2012 17:04:28 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	alan@...rguk.ukuu.org.uk, Dan Carpenter <dan.carpenter@...cle.com>,
	Venkat Venkatsubra <venkat.x.venkatsubra@...cle.com>,
	"David S. Miller" <davem@...emloft.net>,
	James Morris <james.l.morris@...cle.com>,
	Jie Liu <jeff.liu@...cle.com>
Subject: [ 21/31] RDS: fix rds-ping spinlock recursion

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

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

From: "jeff.liu" <jeff.liu@...cle.com>

[ Upstream commit 5175a5e76bbdf20a614fb47ce7a38f0f39e70226 ]

This is the revised patch for fixing rds-ping spinlock recursion
according to Venkat's suggestions.

RDS ping/pong over TCP feature has been broken for years(2.6.39 to
3.6.0) since we have to set TCP cork and call kernel_sendmsg() between
ping/pong which both need to lock "struct sock *sk". However, this
lock has already been hold before rds_tcp_data_ready() callback is
triggerred. As a result, we always facing spinlock resursion which
would resulting in system panic.

Given that RDS ping is only used to test the connectivity and not for
serious performance measurements, we can queue the pong transmit to
rds_wq as a delayed response.

Reported-by: Dan Carpenter <dan.carpenter@...cle.com>
CC: Venkat Venkatsubra <venkat.x.venkatsubra@...cle.com>
CC: David S. Miller <davem@...emloft.net>
CC: James Morris <james.l.morris@...cle.com>
Signed-off-by: Jie Liu <jeff.liu@...cle.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 net/rds/send.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -1121,7 +1121,7 @@ rds_send_pong(struct rds_connection *con
 	rds_stats_inc(s_send_pong);

 	if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
-		rds_send_xmit(conn);
+		queue_delayed_work(rds_wq, &conn->c_send_w, 0);

 	rds_message_put(rm);
 	return 0;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/