From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47042 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754992AbbKQWmJ (ORCPT ); Tue, 17 Nov 2015 17:42:09 -0500 Subject: Patch "tcp: remove improper preemption check in tcp_xmit_probe_skb()" has been added to the 4.2-stable tree To: renatowestphal@gmail.com, davem@davemloft.net, gregkh@linuxfoundation.org, renatow@taghos.com.br Cc: , From: Date: Tue, 17 Nov 2015 14:42:08 -0800 Message-ID: <144780012818102@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled tcp: remove improper preemption check in tcp_xmit_probe_skb() to the 4.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tcp-remove-improper-preemption-check-in-tcp_xmit_probe_skb.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Tue Nov 17 14:34:38 PST 2015 From: Renato Westphal Date: Mon, 19 Oct 2015 18:51:34 -0200 Subject: tcp: remove improper preemption check in tcp_xmit_probe_skb() From: Renato Westphal [ Upstream commit e2e8009ff72ad2a795b67785f3238af152146368 ] Commit e520af48c7e5a introduced the following bug when setting the TCP_REPAIR sockoption: [ 2860.657036] BUG: using __this_cpu_add() in preemptible [00000000] code: daemon/12164 [ 2860.657045] caller is __this_cpu_preempt_check+0x13/0x20 [ 2860.657049] CPU: 1 PID: 12164 Comm: daemon Not tainted 4.2.3 #1 [ 2860.657051] Hardware name: Dell Inc. PowerEdge R210 II/0JP7TR, BIOS 2.0.5 03/13/2012 [ 2860.657054] ffffffff81c7f071 ffff880231e9fdf8 ffffffff8185d765 0000000000000002 [ 2860.657058] 0000000000000001 ffff880231e9fe28 ffffffff8146ed91 ffff880231e9fe18 [ 2860.657062] ffffffff81cd1a5d ffff88023534f200 ffff8800b9811000 ffff880231e9fe38 [ 2860.657065] Call Trace: [ 2860.657072] [] dump_stack+0x4f/0x7b [ 2860.657075] [] check_preemption_disabled+0xe1/0xf0 [ 2860.657078] [] __this_cpu_preempt_check+0x13/0x20 [ 2860.657082] [] tcp_xmit_probe_skb+0xc7/0x100 [ 2860.657085] [] tcp_send_window_probe+0x2d/0x30 [ 2860.657089] [] do_tcp_setsockopt.isra.29+0x74c/0x830 [ 2860.657093] [] tcp_setsockopt+0x2c/0x30 [ 2860.657097] [] sock_common_setsockopt+0x14/0x20 [ 2860.657100] [] SyS_setsockopt+0x71/0xc0 [ 2860.657104] [] entry_SYSCALL_64_fastpath+0x16/0x75 Since tcp_xmit_probe_skb() can be called from process context, use NET_INC_STATS() instead of NET_INC_STATS_BH(). Fixes: e520af48c7e5 ("tcp: add TCPWinProbe and TCPKeepAlive SNMP counters") Signed-off-by: Renato Westphal Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3406,7 +3406,7 @@ static int tcp_xmit_probe_skb(struct soc */ tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPHDR_ACK); skb_mstamp_get(&skb->skb_mstamp); - NET_INC_STATS_BH(sock_net(sk), mib); + NET_INC_STATS(sock_net(sk), mib); return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC); } Patches currently in stable-queue which might be from renatowestphal@gmail.com are queue-4.2/tcp-remove-improper-preemption-check-in-tcp_xmit_probe_skb.patch