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 2271D41B8F6; Fri, 4 Sep 2026 06:16:02 +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=1788502563; cv=none; b=YRhwJtUJaEGgzY3WGXJmATDwdqdw1OD99CV7zKoaO2nSk/vqMjEtGrFzONYc2QBSKpNsLLEfBWJGNbuoh+ef6WyertUstZL2C+z7iO1DXfB1yY+SKQCEG084MHMXlMpD+7WHtH5eiPjrkOKgHzPi0kcZAuCcmJp1Oq1Fo5jbkYA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788502563; c=relaxed/simple; bh=ANi96l13XBfr+GHqJeQnzEWye1CGXhhZexfgZ6pYkhM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mZUZv6OiI5ojk+gr/V73JiGkgCPF3oAlEyKH1yxJdDCnHtZk/nxMjSfQo9OEcHjoyYQukXBQx8pia8f6Rmht4jfrA6+bpdq5qS2g5M/RWTu+XzY86Jr+cdDbV15obY44W7KmyJRHep4YPKj2hdjxDYPNt/HlmXulWCnIzhZHXEU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=iTByANJd; 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="iTByANJd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 71E131F00A3D; Fri, 4 Sep 2026 06:16:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788502562; bh=43Y59Sn669lucozzML/n46PLXhEadWnCnF+ho5y4uNg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=iTByANJdDoLOJq1A4Zmjk6AmTShMP3SYKjIj6O2TuySExfI9UafghqG2dCixQAb9c yG8VOiK8z8yopDLbBxaA4GysRmWhyHnZDYLcfR1VqO0PrkyM5Ox24e65eKJkeDb5Kz o+rEFOGm3f/7LENYBVr2bDd/+9osmERwAckf85iI= 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 6.12 251/403] openvswitch: only skb_tx_error() a packet we are about to drop Date: Fri, 4 Sep 2026 07:00:54 +0200 Message-ID: <20260904045740.577798194@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045734.806166532@linuxfoundation.org> References: <20260904045734.806166532@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 6.12-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 @@ -281,6 +281,7 @@ void ovs_dp_process_packet(struct sk_buf consume_skb(skb); break; default: + skb_tx_error(skb); kfree_skb(skb); break; } @@ -581,8 +582,6 @@ 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);