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 437FBC46467 for ; Sun, 18 Dec 2022 17:04:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233337AbiLRRE0 (ORCPT ); Sun, 18 Dec 2022 12:04:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233089AbiLRRCy (ORCPT ); Sun, 18 Dec 2022 12:02:54 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECE171276C; Sun, 18 Dec 2022 08:21:13 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id CFCD260DCC; Sun, 18 Dec 2022 16:21:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EBFA3C433F0; Sun, 18 Dec 2022 16:21:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671380472; bh=k4yTj0C2jGK8AyiWoJPffHwj2JpKzjvrK1itF90RIZI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YMAbXNvC8mLfwp1dpId3Kixv3GfWFl9wK3zolIJc48puH+ykTpgL7gQDHDJLFOdC8 L9jl5o0zvzzFym1W26ZiBGZ8qgN9Lo4x/HdF1AFBmqjxBXHVXE6Lprou4R9HnZZ3qv 1xlbyl+VkWsS9OQsWevtCOxxM6bjTTzd7Lu36nSN6/pwX0t+dHca6WEpoDub1j112r TMDBG24aJmZGalpAQFirXCH1XCCiyN5vssbZA0Bf8s2JrWgb88uERyZ3JxUIx2MELQ FUls1MD5JDH0HF16Db/EYqXjo0UQoci2penn/qGHUOo83yD9GcAB6en7c3Dx1bpHhg nrqU5SmkIftEQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Stanislav Fomichev , Paul Mackerras , linux-ppp@vger.kernel.org, syzbot+41cab52ab62ee99ed24a@syzkaller.appspotmail.com, "David S . Miller" , Sasha Levin , edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 18/26] ppp: associate skb with a device at tx Date: Sun, 18 Dec 2022 11:20:08 -0500 Message-Id: <20221218162016.934280-18-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218162016.934280-1-sashal@kernel.org> References: <20221218162016.934280-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Stanislav Fomichev [ Upstream commit 9f225444467b98579cf28d94f4ad053460dfdb84 ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 3f335b57d5cd..220b28711f98 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -1528,6 +1528,8 @@ 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 */ -- 2.35.1