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 3C74C346FC3; Fri, 4 Sep 2026 06:00:47 +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=1788501648; cv=none; b=UEomFte171sRrRaWJ3VEevd6np84XE4932K/LRs5LL7xMKRb5tEuByVkX6bqgwIojvWKk+9r45JqE+Su2IihRa5wlXkLVxvI3dNr0hsS5VJp4Zc8nKcglLyn2Iv/T1XvL4HH4Pe6gUipl1RCUX2M/9QbzEJkR5I6/KRSRzZInoY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501648; c=relaxed/simple; bh=ktbe8LLGS3UWXGmJdkZMIb6LXbwmzWYDVqgWTYLKiGY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PJClRmPJnu2U5xajppE27hiHYaeHJwN2RNjWgLsMrZV2So0Vos/N43rjy22yp2Y9KUZamxjJZIQ3tG3xoHZKrE1TrQ3vUr8ItBFRV0DvdMbGXASC+2gXubvihpkXj6HC7fYys1GmSg3Sl1I8DezZmAWokfwuagKjxWtpawSxGUw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=v/c7NIMA; 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="v/c7NIMA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 944FA1F00A3D; Fri, 4 Sep 2026 06:00:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788501647; bh=eOlh8ZMm962BuaVRNvN4IDcKCZynU6RggV6fDOfOdWI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=v/c7NIMALE06sXKR+El0lFBCJjl+uXoutlEJUPP7Tb1sYf3GFDvnCJCsYl90yN6gg 015tj4lnoiL8BKBVufMRWQHFCmAmI2fE4v1y8lUeyLJC6G/56P5H6mA7mlBJ4462sl Ve21EsNmn8uUfVNkufm4gheFxIjoF1nAGvasjoXA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ilya Maximets , Norbert Szetei , Jongmin Jang , Willem de Bruijn , Paolo Abeni Subject: [PATCH 6.18 481/552] net: skbuff: dont touch shared zerocopy state in skb_tx_error() Date: Fri, 4 Sep 2026 07:00:38 +0200 Message-ID: <20260904045801.580549437@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 f66bdb1cc0fcd227a062378f8be0b5873aa5600a upstream. skb_tx_error() completes the zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, and skb_zcopy_downgrade_managed() clears SKBFL_MANAGED_FRAG_REFS. Both live in skb_shinfo(), which every clone shares, while the caller only owns the reference it is about to drop. Through a clone it tells the producer its pages are free and drops SKBFL_SHARED_FRAG for an skb that is still in flight. Open vSwitch reaches this with a non-last OVS_ACTION_ATTR_RECIRC: clone_execute() sends a skb_clone() into ovs_dp_process_packet() while do_execute_actions() keeps forwarding the original, and skb_clone() does not privatise the frags here -- skb_orphan_frags() returns early on SKBFL_DONT_ORPHAN. A flow miss on the clone then strips the marker from the packet still being forwarded, and a later local ESP delivery decrypts in place over frags it does not own privately. Skip it for a cloned skb. Nothing is lost: skb_release_data() clears the zerocopy state once the last reference to the shared data goes. Fixes: 25121173f7b1 ("skb: api to report errors for zero copy skbs") Cc: stable@vger.kernel.org Suggested-by: Ilya Maximets Signed-off-by: Norbert Szetei Reviewed-by: Ilya Maximets Tested-by: Jongmin Jang Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/CFAB292A-674B-4C14-BB2C-BB8830AD5659@doyensec.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/core/skbuff.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1373,10 +1373,13 @@ EXPORT_SYMBOL(skb_dump); * * Report xmit error if a device callback is tracking this skb. * skb must be freed afterwards. + * + * Does nothing for a cloned skb: the zerocopy state lives in + * skb_shinfo(), which the clones share. */ void skb_tx_error(struct sk_buff *skb) { - if (skb) { + if (skb && !skb_cloned(skb)) { skb_zcopy_downgrade_managed(skb); skb_zcopy_clear(skb, true); }