From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3F95C432C0 for ; Tue, 26 Nov 2019 07:13:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 67F2D20659 for ; Tue, 26 Nov 2019 07:13:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=jv-coder.de header.i=@jv-coder.de header.b="bKTWPRla" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727135AbfKZHNy (ORCPT ); Tue, 26 Nov 2019 02:13:54 -0500 Received: from mail.jv-coder.de ([5.9.79.73]:51122 "EHLO mail.jv-coder.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725970AbfKZHNx (ORCPT ); Tue, 26 Nov 2019 02:13:53 -0500 Received: from ubuntu.localdomain (unknown [37.156.92.209]) by mail.jv-coder.de (Postfix) with ESMTPSA id 3E0A09F655; Tue, 26 Nov 2019 07:13:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jv-coder.de; s=dkim; t=1574752430; bh=Noz9QHYidJ4GwdcXAEGxL4c/c5S5jDgoJwtUveDjtdg=; h=From:To:Subject:Date:Message-Id:MIME-Version; b=bKTWPRlaZt9sD4Dwktk+fjFpFAj1uBI8tnsVium7IUdEZtJA9OfdAvY89fGvixg4Q OTIpKWMYTkURF9/IVJN51lXfgrygmBIIX8BPBw58mOt2TZcycmfE4x+aRCskAd6DL3 q/TMRehbwQFtIx/zmpKAjkCJ8KGhkomHDC9vlEC4= From: Joerg Vehlow To: linux-kernel@vger.kernel.org, bigeasy@linutronix.de, trix@redhat.com Cc: Joerg Vehlow Subject: [PATCH RT v3] net/xfrm/input: Protect queue with lock Date: Tue, 26 Nov 2019 08:13:35 +0100 Message-Id: <20191126071335.34661-1-lkml@jv-coder.de> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Vehlow During the skb_queue_splice_init the tasklet could have been preempted and_skb_queue_tail called, which led to an inconsistent queue. Affected are all rt kernels up to 5.0.19-rt11 (due to bh rework). It was found using ipsec stress tests (e.g. ipcomp) in ltp suite. Running them in a continous loop triggered the bug in qemu within 5-10 retries. [ 139.717259] BUG: unable to handle kernel NULL pointer dereference at 0000000000000518 [ 139.717260] PGD 0 P4D 0 [ 139.717262] Oops: 0000 [#1] PREEMPT SMP PTI [ 139.717273] CPU: 2 PID: 11987 Comm: netstress Not tainted 4.19.59-rt24-preemt-rt #1 [ 139.717274] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 [ 139.717306] RIP: 0010:xfrm_trans_reinject+0x97/0xd0 [ 139.717307] Code: 42 eb 45 83 6d b0 01 31 f6 48 8b 42 08 48 c7 42 08 00 00 00 00 48 8b 0a 48 c7 02 00 00 00 00 48 89 41 08 48 89 08 48 8b 42 10 <48> 8b b8 18 05 00 00 48 8b 42 40 e8 d9 e1 4b 00 48 8b 55 a0 48 39 [ 139.717307] RSP: 0018:ffffc900007b37e8 EFLAGS: 00010246 [ 139.717308] RAX: 0000000000000000 RBX: ffffc900007b37e8 RCX: ffff88807db206a8 [ 139.717309] RDX: ffff88807db206a8 RSI: 0000000000000000 RDI: 0000000000000000 [ 139.717309] RBP: ffffc900007b3848 R08: 0000000000000001 R09: ffffc900007b35c8 [ 139.717309] R10: ffffea0001dcfc00 R11: 00000000000890c4 R12: ffff88807db20680 [ 139.717310] R13: 00000000000f4240 R14: 0000000000000000 R15: 0000000000000000 [ 139.717310] FS: 00007f4643034700(0000) GS:ffff88807db00000(0000) knlGS:0000000000000000 [ 139.717311] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 139.717337] CR2: 0000000000000518 CR3: 00000000769c6000 CR4: 00000000000006e0 [ 139.717350] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 139.717350] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 139.717350] Call Trace: [ 139.717387] tasklet_action_common.isra.18+0x6d/0xd0 [ 139.717388] tasklet_action+0x1d/0x20 [ 139.717389] do_current_softirqs+0x196/0x360 [ 139.717390] __local_bh_enable+0x51/0x60 [ 139.717397] ip_finish_output2+0x18b/0x3f0 [ 139.717408] ? task_rq_lock+0x53/0xe0 [ 139.717415] ip_finish_output+0xbe/0x1b0 [ 139.717416] ip_output+0x72/0x100 [ 139.717422] ? ipcomp_output+0x5e/0x280 [ 139.717424] xfrm_output_resume+0x4b5/0x540 [ 139.717436] ? refcount_dec_and_test_checked+0x11/0x20 [ 139.717443] ? kfree_skbmem+0x33/0x80 [ 139.717444] xfrm_output+0xd7/0x110 [ 139.717451] xfrm4_output_finish+0x2b/0x30 [ 139.717452] __xfrm4_output+0x3a/0x50 [ 139.717453] xfrm4_output+0x40/0xe0 [ 139.717454] ? xfrm_dst_check+0x174/0x250 [ 139.717455] ? xfrm4_output+0x40/0xe0 [ 139.717456] ? xfrm_dst_check+0x174/0x250 [ 139.717457] ip_local_out+0x3b/0x50 [ 139.717458] __ip_queue_xmit+0x16b/0x420 [ 139.717464] ip_queue_xmit+0x10/0x20 [ 139.717466] __tcp_transmit_skb+0x566/0xad0 [ 139.717467] tcp_write_xmit+0x3a4/0x1050 [ 139.717468] __tcp_push_pending_frames+0x35/0xe0 [ 139.717469] tcp_push+0xdb/0x100 [ 139.717469] tcp_sendmsg_locked+0x491/0xd70 [ 139.717470] tcp_sendmsg+0x2c/0x50 [ 139.717476] inet_sendmsg+0x3e/0xf0 [ 139.717483] sock_sendmsg+0x3e/0x50 [ 139.717484] __sys_sendto+0x114/0x1a0 [ 139.717491] ? __rt_mutex_unlock+0xe/0x10 [ 139.717492] ? _mutex_unlock+0xe/0x10 [ 139.717500] ? ksys_write+0xc5/0xe0 [ 139.717501] __x64_sys_sendto+0x28/0x30 [ 139.717503] do_syscall_64+0x4d/0x110 [ 139.717504] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Joerg Vehlow --- net/xfrm/xfrm_input.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c index 790b514f86b6..4c4e669fcd16 100644 --- a/net/xfrm/xfrm_input.c +++ b/net/xfrm/xfrm_input.c @@ -512,12 +512,15 @@ EXPORT_SYMBOL(xfrm_input_resume); static void xfrm_trans_reinject(unsigned long data) { + unsigned long flags; struct xfrm_trans_tasklet *trans = (void *)data; struct sk_buff_head queue; struct sk_buff *skb; __skb_queue_head_init(&queue); + spin_lock_irqsave(&trans->queue.lock, flags); skb_queue_splice_init(&trans->queue, &queue); + spin_unlock_irqrestore(&trans->queue.lock, flags); while ((skb = __skb_dequeue(&queue))) XFRM_TRANS_SKB_CB(skb)->finish(dev_net(skb->dev), NULL, skb); @@ -535,7 +538,7 @@ int xfrm_trans_queue(struct sk_buff *skb, return -ENOBUFS; XFRM_TRANS_SKB_CB(skb)->finish = finish; - __skb_queue_tail(&trans->queue, skb); + skb_queue_tail(&trans->queue, skb); tasklet_schedule(&trans->tasklet); return 0; } @@ -560,7 +563,7 @@ void __init xfrm_input_init(void) struct xfrm_trans_tasklet *trans; trans = &per_cpu(xfrm_trans_tasklet, i); - __skb_queue_head_init(&trans->queue); + skb_queue_head_init(&trans->queue); tasklet_init(&trans->tasklet, xfrm_trans_reinject, (unsigned long)trans); } -- 2.20.1