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 E96101C3BEB; Tue, 11 Mar 2025 15:16:39 +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=1741706200; cv=none; b=GeIjsMOG2OoXOU6I8sUpaBPoW4231Zb9B2cb5R7QZE7c5/bNb/lWXB5a5pL72U8wfvgjPawJnHwQp/ajYCmrOD1F1VC8rZ9vPJ7jWY0ff+d5j1PmHSQ0WCLyhBIgQjukN0B9Xa/AHLcqbJ42i9fDnfxErgkR7skpUtViocJyNKU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741706200; c=relaxed/simple; bh=wWOw7zQMYSSSGSGk6THglX/BV3W6QvVfO0BrX8LDtZ4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RXf5qZDlQKynFVHstws70c0WGRZ6qe7ibIUzjh8+OsEG2juxITZG1Wpo2UaySzFNC/fcGBx0dydepdePwu5TS/uc7T01o+4OSKTQv67/HqwwShh7JvyR1h96Abew6ACPKq5hm2F4/B5aTK2BOjcBd5ivmKrq7n1naF8/NxIwcyI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=2rt0kuWn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="2rt0kuWn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC51FC4CEEC; Tue, 11 Mar 2025 15:16:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741706199; bh=wWOw7zQMYSSSGSGk6THglX/BV3W6QvVfO0BrX8LDtZ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2rt0kuWnH2cXfsBTwX/K9KVSkPNZoJ8nFVxfgdO2PBV7DQf9/MSCkvx9LPqXEoZHg +0fPl6Imxc/PD9EkgR6/Js3KswN5HCauaSYjQLn/W2WfCSi19tksql7IQBQXKt/Jws javSZ1bTM8XV9OaUd5/J17iTJK8Ypf/rvHhJo6Lw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Antoine Tenart , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.4 296/328] net: gso: fix ownership in __udp_gso_segment Date: Tue, 11 Mar 2025 16:01:06 +0100 Message-ID: <20250311145726.671696992@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250311145714.865727435@linuxfoundation.org> References: <20250311145714.865727435@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Antoine Tenart [ Upstream commit ee01b2f2d7d0010787c2343463965bbc283a497f ] In __udp_gso_segment the skb destructor is removed before segmenting the skb but the socket reference is kept as-is. This is an issue if the original skb is later orphaned as we can hit the following bug: kernel BUG at ./include/linux/skbuff.h:3312! (skb_orphan) RIP: 0010:ip_rcv_core+0x8b2/0xca0 Call Trace: ip_rcv+0xab/0x6e0 __netif_receive_skb_one_core+0x168/0x1b0 process_backlog+0x384/0x1100 __napi_poll.constprop.0+0xa1/0x370 net_rx_action+0x925/0xe50 The above can happen following a sequence of events when using OpenVSwitch, when an OVS_ACTION_ATTR_USERSPACE action precedes an OVS_ACTION_ATTR_OUTPUT action: 1. OVS_ACTION_ATTR_USERSPACE is handled (in do_execute_actions): the skb goes through queue_gso_packets and then __udp_gso_segment, where its destructor is removed. 2. The segments' data are copied and sent to userspace. 3. OVS_ACTION_ATTR_OUTPUT is handled (in do_execute_actions) and the same original skb is sent to its path. 4. If it later hits skb_orphan, we hit the bug. Fix this by also removing the reference to the socket in __udp_gso_segment. Fixes: ad405857b174 ("udp: better wmem accounting on gso") Signed-off-by: Antoine Tenart Link: https://patch.msgid.link/20250226171352.258045-1-atenart@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/udp_offload.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 487a92d75c703..6505a6fd245a6 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -204,13 +204,17 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, /* clear destructor to avoid skb_segment assigning it to tail */ copy_dtor = gso_skb->destructor == sock_wfree; - if (copy_dtor) + if (copy_dtor) { gso_skb->destructor = NULL; + gso_skb->sk = NULL; + } segs = skb_segment(gso_skb, features); if (IS_ERR_OR_NULL(segs)) { - if (copy_dtor) + if (copy_dtor) { gso_skb->destructor = sock_wfree; + gso_skb->sk = sk; + } return segs; } -- 2.39.5