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 52B1BC4167B for ; Sun, 18 Dec 2022 17:13:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233344AbiLRRNI (ORCPT ); Sun, 18 Dec 2022 12:13:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233625AbiLRRKW (ORCPT ); Sun, 18 Dec 2022 12:10:22 -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 886D51EAF6; Sun, 18 Dec 2022 08:23:44 -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 0AAD060C40; Sun, 18 Dec 2022 16:23:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 206F4C43392; Sun, 18 Dec 2022 16:23:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671380623; bh=U+cQHrDmIK+r9qwVg+CRg/eCGO+GgpLzZ8wc3TPMRA0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oRvKOQ+3jcOnu3tc0kPfowfUdqnOt2ERnuOECf84ZP4zewFGK04M+RYD7CR8p3gVJ 5AdamElk84Yb+2ccHkEv0De+k4tTbs4We6MqaVYYfWO+jSEEf6XOSns0xXAWYDn+jU yzvnvwADsj2z70UGSXeVQcaZQVv1232foSp7mkFyRQ3ByPlUEupkxpTvBKkJqA0Ieg tLqgG6C2RRxYEpjN28S7FLyXqDlXr7gXNfopPjSdGTGbRufVchboCeec+4droonNsG 7aaPkOcaP55GMmCebGbhLNZvLZD2PpHJED7IlsLsaGE74JIAU8bz/TE8Nc8V8O3ykU xjbIruA4gcXBw== 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 4.9 14/20] ppp: associate skb with a device at tx Date: Sun, 18 Dec 2022 11:22:59 -0500 Message-Id: <20221218162305.935724-14-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218162305.935724-1-sashal@kernel.org> References: <20221218162305.935724-1-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: bpf@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 6287d2ad77c6..f6cf25cba16e 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -1541,6 +1541,8 @@ 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