From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f179.google.com (mail-dy1-f179.google.com [74.125.82.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D943A24BBF0 for ; Fri, 8 May 2026 01:59:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778205605; cv=none; b=VryrQHyhZAV4mkJMvo8dixKDlM1fXnVZ/iErushKVekI28IMDG/alefjK6pAE5bFeXwuMviRKLRf6iLHO2tDxWAQUOtpgdQbTBMWrAYhyxsyU0jWUc6t9tK+xcQ1Q6a/9/v8yjm/ZSevER2Pl3TYHmfhaRtgmCJfbVKlAmXNhk8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778205605; c=relaxed/simple; bh=n4p8Wazm5mRWef7fULkKI12PxnYi9537npSj+nYtDv0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Nq5Nqz0MaWP/VoI4dGbGEnkF2D1trawOfGfCXGpePmLtvZSCWIsEIjZDPNel9IUoxyrtf60IHZb+3psuBmocw1wS+Bio7fQo8F50VXxOMYukej4gS+ZhS64jaEoWG1JPl86kUWtwFtgxI+DoYGt8YIJeOULwnFNkDS+4bAgAlTs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=networkplumber.org; spf=pass smtp.mailfrom=networkplumber.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20251104.gappssmtp.com header.i=@networkplumber-org.20251104.gappssmtp.com header.b=Kc2UWfMo; arc=none smtp.client-ip=74.125.82.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=networkplumber.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=networkplumber.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20251104.gappssmtp.com header.i=@networkplumber-org.20251104.gappssmtp.com header.b="Kc2UWfMo" Received: by mail-dy1-f179.google.com with SMTP id 5a478bee46e88-2f7ca62a3c4so947411eec.0 for ; Thu, 07 May 2026 18:59:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20251104.gappssmtp.com; s=20251104; t=1778205593; x=1778810393; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=TO7r/0+4S0y4yz1yQOkpBoCSLB5Ya43l7K/dBhK3N5U=; b=Kc2UWfMoUBNLu57oSFa+ZAlwM6bHEPIKAPGIT6MkGdRsEHOxdLsuOJ4V44VEzNzCaO MfY0r5CxII1B7B+VcWDRJNgCGJKEA+RG5iNORECxJt/DZa2AY1RsxM8NlI+k7sC/c6Ei Y94QW4oY2ftW3JaTgpzQLT9wqoR+wleBpYCfpZPlYFEZZ42vtiOKT01tS8OEhUdMf3NL X4xTbMMNfTM/OUPAvO4Jn2Y7cRFGuSmPspFSvBWfdLcgEvOe1cnPsVJbLGEFicNtEA8A tcQ3TBNKyFVYAQxBxfbG/l7N6ZqCqJG7xpZIHQlb/fTaaoCsE5Tqu/uVyxU9SuzztJia 8AfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778205593; x=1778810393; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=TO7r/0+4S0y4yz1yQOkpBoCSLB5Ya43l7K/dBhK3N5U=; b=Vz6rsUNGlEUFE/Odp0SXL6P+8xDRFzYib5/sFyiUpgRsvbaNaZSbdEXd+ykVfV+ScQ +bG4lxoJX0+T30BKvOlsg3yNWUfu17u8k6JQMHyGM9XuKlAecf++3oL0e0cBqa6o1K2r wUusihrRNGUDjqKg8fRe2aF7LXwFYyVn3F+8B1shcpVXS5TNlkmgcKB47Co8sjXpMJQY kou+BskIi9EhN/hhSGlcipCgMHNZjYAWV6WsskbRpcwsEUTgSmaIWeMZdrF7ZgPy6+MZ pjEysyEq8MbasXsZw+wMuSsO2JlcaMwSdNYvBEteb9BxFPlK1Zj2mLDnpURbI88lyMJS eDnQ== X-Forwarded-Encrypted: i=1; AFNElJ9gVikH6xKlE04GHCn48AA+rFZ9ZBzYLHuOiTXETBHESekW0TdQFhZv27CfPnk7J50ezfBCFoiLx0d/XAM=@vger.kernel.org X-Gm-Message-State: AOJu0Yw2dUfTX/0gne9+yvxzWP6Qtfve8uv/unnFfA2+6XVE9wYvtkmM Ti4gGbPsYG9eZnyC+MPoTipZO81Z0r+FAus3qcxINSQPNeS62gz0vB5BC6I6YXYu4Fk= X-Gm-Gg: Acq92OHVX5uiv17Wkt4uV3nhkx2c5fcoTg+lwceTnN1kcPzYT3i5MDSSGCd9Ybd2zJy vAcwwr8fYD1yVN/sZ6X0AOhp8gKtIk+ooEDcDeE9k22C/EWh3hxaGTcBualpi8uoP8mY2+F1Qwx gLHx8EfUZA5TIfPeOWdt5Bp7R7vcegQPSW2Uweo0DPz2Yv3ZTkfKDkSHsnZB/XBHF7ZA9J8d6vQ 1GAHy7ajlEaLjowYH9zxmT4+luEYSViIraTBH74RvCexA1GUwbd3kjpl9OyPFaTPhaSe6hWodEe N/znGqyAObtDQtRAI6YG/AVHgsPzmp7YxLVyQ/QWHQfSB97iBEP/Ft4JrhhFGGQF7C+v1KL0mcD q0qFSZHMMHNs8RPwXG5+EUOGQHeywcbA43pL3O9WbBDRuSnEbg8fD5yneX0zF7w3a2H6eOOEm36 AeNfxj3fWDcGJeKMrY9Zlcsb2KPGhZqgEP X-Received: by 2002:a05:7301:168b:b0:2ed:e14:7f54 with SMTP id 5a478bee46e88-2f54e47ec98mr4509673eec.30.1778205592917; Thu, 07 May 2026 18:59:52 -0700 (PDT) Received: from phoenix.lan ([104.202.41.210]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-2f88847504dsm324090eec.15.2026.05.07.18.59.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2026 18:59:52 -0700 (PDT) From: Stephen Hemminger To: netdev@vger.kernel.org Cc: jhs@mojatatu.com, Stephen Hemminger , Jiri Pirko , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v4 4/5] net/sched: netem: handle multi-segment skb in corruption Date: Thu, 7 May 2026 18:55:20 -0700 Message-ID: <20260508015940.554462-5-stephen@networkplumber.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260508015940.554462-1-stephen@networkplumber.org> References: <20260508015940.554462-1-stephen@networkplumber.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The packet corruption code only flipped bits in the linear header portion of the skb, skipping corruption when skb_headlen() was zero. Linearize the whole skb if necessary before corruption. Extends d64cb81dcbd5 ("net/sched: sch_netem: fix out-of-bounds access in packet corruption") with a more general solution. Signed-off-by: Stephen Hemminger --- net/sched/sch_netem.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 53bdfa77ee2d..37df05bf43ee 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -513,16 +513,17 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch, qdisc_qstats_drop(sch); goto finish_segs; } - if (skb->ip_summed == CHECKSUM_PARTIAL && - skb_checksum_help(skb)) { + if (skb_linearize(skb) || + (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))) { qdisc_drop(skb, sch, to_free); skb = NULL; goto finish_segs; } - if (skb_headlen(skb)) - skb->data[get_random_u32_below(skb_headlen(skb))] ^= - 1 << get_random_u32_below(8); + if (skb->len) { + u32 offset = get_random_u32_below(skb->len); + skb->data[offset] ^= 1 << get_random_u32_below(8); + } } if (unlikely(sch->q.qlen >= sch->limit)) { -- 2.53.0