From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 11D30B64A for ; Wed, 14 Feb 2024 03:38:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707881936; cv=none; b=YmSOVee9EKreoExoiLCqHDCSKyEyZ8mklBB0l1SXSvEp84lDyNWPWgIgdLG4fMAYzG8xsiZbgj31TcpurtD1I9yNmwhm19MUT6J9MNMOBZ+4m22agTK3FIfW2GVerDSRz1Zg1nP0F82ydutTZjF/01Y2wwq0wFM9DATep9UjI9M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707881936; c=relaxed/simple; bh=3SOk16hiasuTE9/BDUHVgSUmJz6Ked7mnkxTAyWVP6I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XnjwXNwW1crmPhoeaXCldv5Ta+sNtB0IsB5pVhbU8lrVSo4si6CbNXNc4la66Fp+IvY4FYSmsVnZW+J2G60aX7tASzkXKXttKtEZIAoBjD/U7ACcs2AfRUBgUBYteEgaCVbvQF8IIlaifhKegebh+jCNA53DF3s7/3IALuaz/CE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qLsTZ+1R; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qLsTZ+1R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C296C433C7; Wed, 14 Feb 2024 03:38:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707881935; bh=3SOk16hiasuTE9/BDUHVgSUmJz6Ked7mnkxTAyWVP6I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qLsTZ+1RPs7AlqCpzdAlV8jzQJeAqKIzE2Ar5DhGLhbHELgKfEPjKwuiQmt2dT+5K AdgcrxhdR+srZHCmSrvVnLYOe2cQlN2z6uXUQ06vh2AYpGx7HPd8OroXT5c8oSjvSB VyPNA/Ibag+WNwVvqKdeeFs8IfC4v9u0m8FmpBbVXOPfrtpm6ZMleeEQcrucm2eQyf eKrpYfDXIEZzD1GBQC5VPUXrbWbYfRmREIrBECtfTMpu8++MIl9ivYkC3ONNrgMQ59 oJVVKI1quD56DA8+sgkAhK4Y+TWqkx5FFXPI2yxlzmEr4T2397QBR82teko+ElZslx Ghxl0+lWdYSJg== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, Jakub Kicinski , jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us Subject: [PATCH net v2 2/2] net/sched: act_mirred: don't override retval if we already lost the skb Date: Tue, 13 Feb 2024 19:38:48 -0800 Message-ID: <20240214033848.981211-2-kuba@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240214033848.981211-1-kuba@kernel.org> References: <20240214033848.981211-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit If we're redirecting the skb, and haven't called tcf_mirred_forward(), yet, we need to tell the core to drop the skb by setting the retcode to SHOT. If we have called tcf_mirred_forward(), however, the skb is out of our hands and returning SHOT will lead to UaF. Move the retval override to the error path which actually need it. Fixes: e5cf1baf92cb ("act_mirred: use TC_ACT_REINSERT when possible") Signed-off-by: Jakub Kicinski --- CC: jhs@mojatatu.com CC: xiyou.wangcong@gmail.com CC: jiri@resnulli.us --- net/sched/act_mirred.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index 291d47c9eb69..6faa7d00da09 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -266,8 +266,7 @@ static int tcf_mirred_to_dev(struct sk_buff *skb, struct tcf_mirred *m, if (unlikely(!(dev->flags & IFF_UP)) || !netif_carrier_ok(dev)) { net_notice_ratelimited("tc mirred to Houston: device %s is down\n", dev->name); - err = -ENODEV; - goto out; + goto err_cant_do; } /* we could easily avoid the clone only if called by ingress and clsact; @@ -279,10 +278,8 @@ static int tcf_mirred_to_dev(struct sk_buff *skb, struct tcf_mirred *m, tcf_mirred_can_reinsert(retval); if (!dont_clone) { skb_to_send = skb_clone(skb, GFP_ATOMIC); - if (!skb_to_send) { - err = -ENOMEM; - goto out; - } + if (!skb_to_send) + goto err_cant_do; } want_ingress = tcf_mirred_act_wants_ingress(m_eaction); @@ -319,15 +316,16 @@ static int tcf_mirred_to_dev(struct sk_buff *skb, struct tcf_mirred *m, } else { err = tcf_mirred_forward(at_ingress, want_ingress, skb_to_send); } - - if (err) { -out: + if (err) tcf_action_inc_overlimit_qstats(&m->common); - if (is_redirect) - retval = TC_ACT_SHOT; - } return retval; + +err_cant_do: + if (is_redirect) + retval = TC_ACT_SHOT; + tcf_action_inc_overlimit_qstats(&m->common); + return retval; } static int tcf_blockcast_redir(struct sk_buff *skb, struct tcf_mirred *m, -- 2.43.0