From patchwork Thu Feb 15 14:33:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 13558498 X-Patchwork-Delegate: kuba@kernel.org 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 6F4FE132466 for ; Thu, 15 Feb 2024 14:33:49 +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=1708007629; cv=none; b=gRSTncqNr/6P5UZiUhNgdUjnyjosWP9N7KsRHCpeQtAYlZGBLgoTYzGYtio9gm3UPu/w6JSXrcFGRH+JoFKq2M1vuM1kAdKnqKZyU2OVWlG7m21qq4ClXxpQMUts/Ap5v8/urQllLMzdl0W+PZnzBEB6OZ0UaaUgPk+JYtgVnQY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708007629; c=relaxed/simple; bh=5s8cNNhQRYyrqVCXz7NI/5KvK73sRuHxFI0BlrRsZ+0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CR9tGka0VExqne4oCIEMjTMtVLJeQ/dQy5wUc+w2T46Ti6M81XNfU/JfWTg2It0rXkX4BnbqvB+SlmwNNZOdtoDbCExJkU+DlLDus9sa5n74CzFFl9kMHT2CCWnO0Xir8reGdn+731dayKnjOsPI2OaeanZxctV8dk8ZWjdbH8w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aGdRG/M1; 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="aGdRG/M1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84349C43390; Thu, 15 Feb 2024 14:33:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708007628; bh=5s8cNNhQRYyrqVCXz7NI/5KvK73sRuHxFI0BlrRsZ+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aGdRG/M1xeeGtTQz0XKWEKbfM22ZPbvVINokcixZrL2mCIyxU6uQItaXyBso+qjBT F/D+3Pkw3A+tv3IBNHGbq0BFvRcp9259dV+Z37X5j/3uuJegZJYe+eFc3rYp845Lrj GjgDjlMbUiQCYQauHf4zh/Sx/v65TyYzCPFr75mdVy3NtIW/yiRGMnEEsXoqYxMmbF QqKhv+eRqoFzsZu+3PVnOhb/nOUoCqUfnCYVo76W7bTLjXxkLurlj7ZrkDaGIikFSU j4tQIh+I7kDDvYbr3pxxHAp37+dDh2M6J/mZo67OCxcE1zcC/eviMn4uhyUpu0OCMo w9HlCJOwYkxKA== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, Jakub Kicinski , Michal Swiatkowski , jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us Subject: [PATCH net v3 2/2] net/sched: act_mirred: don't override retval if we already lost the skb Date: Thu, 15 Feb 2024 06:33:46 -0800 Message-ID: <20240215143346.1715054-2-kuba@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240215143346.1715054-1-kuba@kernel.org> References: <20240215143346.1715054-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org 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. Reviewed-by: Michal Swiatkowski Fixes: e5cf1baf92cb ("act_mirred: use TC_ACT_REINSERT when possible") Signed-off-by: Jakub Kicinski Acked-by: Jamal Hadi Salim --- 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,