From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 71B44411FBF; Fri, 4 Sep 2026 05:54:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501258; cv=none; b=R1lQuXxtqTJ/dVNn+NVb/r7TK4eFu/pdVmN759ulG6mUVMnIgffI3oF8pvzK3PI5AALLI7jYCdyMW0AIA5rtq+EXlIemTqUHHUbEqwNDcV7S/QC7bSy99umXiEAnl1YF4eUO+kkB+DKiuahDIQjCI6bRr5mXinhGWy4XmFSriDw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501258; c=relaxed/simple; bh=Th6+yGq+NNV/X/ZaHa7lvRggPWfKFC4sNP+RJhxSJOU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ot8ksnxuCoscYRQpPG05qhQIOtTDTSwrcr1wXH74srJ0R9/cpAB9B/AIa1VVPtyTKKFhSoCmNYTnbHXVMB+9QW9ve234E4cEI84R2b9WCdeB0+U/q2Z5LXjwn1PJg3kGMa3eu4m5LpAQyToACD+jPE9eDuh6eJSTTz2KI0EDj5s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Znh+GFtc; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Znh+GFtc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9C5D1F00A3D; Fri, 4 Sep 2026 05:54:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788501257; bh=NWpxzLKeJjVd/LQmwotUEIBwST5e0xv+gnnO98GgW1s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Znh+GFtco9nQpg8Jct6LuftLvfeQZyISId2PX3kRkz3SQ6HcpxPpeQWhTZKdBMrag q+bFCLsuef8hDA9otHvkwoR3OFXLRxEGFPocIMIS6MPmONkVKWkVWp5asz6hLnMHSg J8rQX3Jv2YvgajQmKGwxEaL5mWk7tRB3E5dzsdag= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Norbert Szetei , Ilya Maximets , Jongmin Jang , Paolo Abeni Subject: [PATCH 6.18 344/552] openvswitch: only skb_tx_error() a packet we are about to drop Date: Fri, 4 Sep 2026 06:58:21 +0200 Message-ID: <20260904045758.052878869@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045747.813364717@linuxfoundation.org> References: <20260904045747.813364717@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Norbert Szetei commit 0dbc2398fca3bb33eda963849f865ddb1b3aa05e upstream. queue_userspace_packet() borrows the packet skb -- it only copies it into a private netlink message (user_skb) and does not own it; on return do_execute_actions() keeps forwarding it through the flow's remaining actions. Its error path nevertheless calls skb_tx_error(skb), which via skb_zcopy_clear() does skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY, stripping SKBFL_SHARED_FRAG from that live skb (skb_tx_error()'s kerneldoc says "skb must be freed afterwards"). For a MSG_ZEROCOPY skb carrying page-cache frags, SKBFL_SHARED_FRAG is what makes esp_input() skb_cow_data() before in-place AEAD; once it is stripped a later local ESP-in-UDP delivery decrypts in place over pages the sender does not own -- an unprivileged page-cache write (the "Fragnesia" primitive). do_execute_actions() ignores output_userspace()'s return value, so any action after a failed USERSPACE upcall inherits the stripped skb. Move the skb_tx_error() to the flow-miss drop path - the "default" branch of ovs_dp_process_packet()'s switch(error), before kfree_skb(). The call has been here since commit 36d5fe6a0007 ("core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors") but was harmless until esp_input() began relying on SKBFL_SHARED_FRAG to gate in-place decrypt; only then did stripping it on a still-forwarded skb become a page-cache write primitive. Fixes: 36d5fe6a0007 ("core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors") Fixes: f4c50a4034e6 ("xfrm: esp: avoid in-place decrypt on shared skb frags") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-5 Signed-off-by: Norbert Szetei Reviewed-by: Ilya Maximets Tested-by: Jongmin Jang Link: https://patch.msgid.link/55A52703-7548-4A55-A9CE-2A37145BDCAD@doyensec.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/openvswitch/datapath.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -285,6 +285,7 @@ void ovs_dp_process_packet(struct sk_buf consume_skb(skb); break; default: + skb_tx_error(skb); kfree_skb(skb); break; } @@ -601,8 +602,6 @@ static int queue_userspace_packet(struct err = genlmsg_unicast(ovs_dp_get_net(dp), user_skb, upcall_info->portid); user_skb = NULL; out: - if (err) - skb_tx_error(skb); consume_skb(user_skb); consume_skb(nskb);