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 73DA840F754; Fri, 4 Sep 2026 06:21:13 +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=1788502874; cv=none; b=BeilgP7LDpbNLIsf/N9Yg1f4n2aNmXIHFtnNhU4WckCFqKmkctQqX0cMzppOblGRtUEFJc63MWT4T3ln0Ye90Wx7TKgDCEBqOFDA29AkPZs2P0E26/8C7Wr7ICc6g5zaLgHym8cQVGSj+n390vHMGYemp21BrY/SiW/hICNUSuw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788502874; c=relaxed/simple; bh=nU0oL85gUEN2aYcbDvNvTox1kV1NOP9cfx7E1iLwhGw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CfdROvZJnSXkBoh98ndGP2idvQwzqWNd9pDAzcnWT0ZjsquLDa+qRqzidAWAyVkoFIQhxwRhvUjD/uXi4CfKfxctJ5/vi4bVubA36IapGd+eBw9R2pQ1vzB3SmGS06uNDMl8cfMER6aiTpoRaWwLI13xj2U4RIIDfjYwNm622c0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WVZOLHHw; 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="WVZOLHHw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA4C01F00A3D; Fri, 4 Sep 2026 06:21:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788502873; bh=QTK+bNe8UjXA8701WcA6U7ygHXMv003aGNqsYsLx4ng=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WVZOLHHwsrMpkzxC/sHOAsKd4AgVu9BeBa2FH84ygjvAdmsnVkNC0CwmoaQUKLvsM GQBZc38lXxEwieGSD+mAahdHdpV0DlQ+SVhiYnt11L8P/xtBCZwySrOOe4gJ3S0p1V nsiNrLACEKFbcbOKX0o/w6MAhvVZW02bwsvUaJz8= 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 6.12 358/403] net: skbuff: dont touch shared zerocopy state in skb_tx_error() Date: Fri, 4 Sep 2026 07:02:41 +0200 Message-ID: <20260904045742.955429978@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 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 @@ -1403,10 +1403,13 @@ 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); }