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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF755C433FE for ; Mon, 21 Nov 2022 18:29:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229605AbiKUS3R (ORCPT ); Mon, 21 Nov 2022 13:29:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229604AbiKUS3Q (ORCPT ); Mon, 21 Nov 2022 13:29:16 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D01FFD06F3 for ; Mon, 21 Nov 2022 10:29:15 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id t5-20020a5b07c5000000b006dfa2102debso11635643ybq.4 for ; Mon, 21 Nov 2022 10:29:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=EpRKKSjGU4jU5Fg7oLYgcrsizQF6B4l3aKjhPZhJTYQ=; b=WGyPIRvE7xm89yZZC0yh7Y/evxJvHEVZ6kEII7KWNOY7r3r2gWDfaerXYm1jwJ68jn lA4IESJ9ahupM3UT4DYXtfNk5qudY+GL+nWYTk68EcR675T9JZ1uqNfcOrmw+EOuPb+7 r4IobcByfs5zDRlp1t5/AO++HaxGuq3MW1xpPj33EdveELYOrd3DvLFsg1K9PstXV4pf CHqFF+1O3Nw7K91kLY55gNMj2CmLG4KYG382goF5EqXc+SOyI6cKaIog2nEFdBQhX/yd M0mcUwv+DjOBBUjzqFwJ2rwg5rhXMJUkSWp11ozbNKVQkI+cijCOYqQISeeCrVr/1XPV 8G4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=EpRKKSjGU4jU5Fg7oLYgcrsizQF6B4l3aKjhPZhJTYQ=; b=fGh7wJMTJY7DiZ9ODmivfAoZZurK8jSo/YZx8U8TeLxCdMUk5l4qLHYYvI+d+XjL+3 KALqfgWvXajt67GRaJVyliHi9BN9lpYcLhRRd3ZDFP6vIC9S6l9UnKZeABrbO2frzndw yHfqIe2Jgt3rC0YuHwFN99h3sQwCHhBPVcWJLwbLnlgYgCwE8ThC9i/L3exKKL0anlG9 Hn7a3eyjeo9kswbVnQbl2CYv1cS++jM7HBXwaTPuBZinVtCV2zN+SS7LVim+x4/j8rcl mddCdUfKeJsmmvD74hHi0/Y155G0vp9PcnRnAl035P4MHyIl4ZyS/57hWsdyYdKBUzbf Bx7w== X-Gm-Message-State: ANoB5pnm3OfJiZPkfiZ585c/I4N6omIa7LOnQDPrgP3+18SUlS22q4tc xdxPm+P4jC4nR4R5skUgiZQcZfk= X-Google-Smtp-Source: AA0mqf6ndnxDk4mb2nv00gdQZTM/qoTHu4mqJPKEzXtmHvNAnQr6dyOZC4fxSojVnefOxuNCqOXyUEQ= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:a25:cf42:0:b0:6dd:cb46:84f1 with SMTP id f63-20020a25cf42000000b006ddcb4684f1mr2617387ybg.159.1669055354696; Mon, 21 Nov 2022 10:29:14 -0800 (PST) Date: Mon, 21 Nov 2022 10:29:13 -0800 Mime-Version: 1.0 X-Mailer: git-send-email 2.38.1.584.g0f3c55d4c2-goog Message-ID: <20221121182913.2166006-1-sdf@google.com> Subject: [PATCH net-next] ppp: associate skb with a device at tx From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, Stanislav Fomichev , Paul Mackerras , linux-ppp@vger.kernel.org, syzbot+41cab52ab62ee99ed24a@syzkaller.appspotmail.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-ppp@vger.kernel.org Syzkaller triggered flow dissector warning with the following: r0 = openat$ppp(0xffffffffffffff9c, &(0x7f0000000000), 0xc0802, 0x0) ioctl$PPPIOCNEWUNIT(r0, 0xc004743e, &(0x7f00000000c0)) ioctl$PPPIOCSACTIVE(r0, 0x40107446, &(0x7f0000000240)={0x2, &(0x7f0000000180)=[{0x20, 0x0, 0x0, 0xfffff034}, {0x6}]}) pwritev(r0, &(0x7f0000000040)=[{&(0x7f0000000140)='\x00!', 0x2}], 0x1, 0x0, 0x0) [ 9.485814] WARNING: CPU: 3 PID: 329 at net/core/flow_dissector.c:1016 __skb_flow_dissect+0x1ee0/0x1fa0 [ 9.485929] skb_get_poff+0x53/0xa0 [ 9.485937] bpf_skb_get_pay_offset+0xe/0x20 [ 9.485944] ? ppp_send_frame+0xc2/0x5b0 [ 9.485949] ? _raw_spin_unlock_irqrestore+0x40/0x60 [ 9.485958] ? __ppp_xmit_process+0x7a/0xe0 [ 9.485968] ? ppp_xmit_process+0x5b/0xb0 [ 9.485974] ? ppp_write+0x12a/0x190 [ 9.485981] ? do_iter_write+0x18e/0x2d0 [ 9.485987] ? __import_iovec+0x30/0x130 [ 9.485997] ? do_pwritev+0x1b6/0x240 [ 9.486016] ? trace_hardirqs_on+0x47/0x50 [ 9.486023] ? __x64_sys_pwritev+0x24/0x30 [ 9.486026] ? do_syscall_64+0x3d/0x80 [ 9.486031] ? entry_SYSCALL_64_after_hwframe+0x63/0xcd Flow dissector tries to find skb net namespace either via device or via socket. Neigher is set in ppp_send_frame, so let's manually use ppp->dev. Cc: Paul Mackerras Cc: linux-ppp@vger.kernel.org Reported-by: syzbot+41cab52ab62ee99ed24a@syzkaller.appspotmail.com Signed-off-by: Stanislav Fomichev --- drivers/net/ppp/ppp_generic.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index 9206c660a72e..d4c821c8cf57 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -1743,6 +1743,8 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) int len; unsigned char *cp; + skb->dev = ppp->dev; + if (proto < 0x8000) { #ifdef CONFIG_PPP_FILTER /* check if we should pass this packet */ -- 2.38.1.584.g0f3c55d4c2-goog