From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793364729; b=ZaVgfxd2ur5PcOPvRWW7LRZiL/GgwH4JyVmJVQdB7n7SJWzMnCejg4Eh5sJGhJ27K4cj ZI3/aAuAO3MVgZmJD1MxrkZOnJs5zoJ6Xoljm9rMnkT9a161F2pTV34MVBzKZ+2vlt1XL 2zKS3xMqsBestpHQqpwBJFlk9q4kgHcf2SRNbpASiJQ8QqspYRzXs4tPwFn1QTtEKhLKH Hh3bb9+u3ql8SZNVlFpC95wxvNZAtzpKmlrJ2wq03TyFLxpQpVZHjfsrMCLRexNLMuf2Z /7vDdqYGweDMTk66N8gNwVU5pqgl8dz7O8j0+VUgejLdOsNIyAi3+4sGlKKG7tURw0w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793364729; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=uK3WvoVy0YSvuCfLBv5IV9n4exSO2EGy5EbkcEXAMng=; b=j+4+yzRxV76WLnmXamrHeMl12ds6GqQBixQ4cTia9kZy7YsU28zikjqWiQAId7M3X5hM uOvoSb+PgcxrF8vn8pC3ChHXH8MdVTj4+DjzD+gSz/+JnouL6k1M0hAm/nwOG3kbI2pNa QFaZDOabO4sinaGKbpYdJ6sE46WZQ5GsEWkNAvsMhsWEEMhnz5GPPEBkKLq9IhepwgPfN 0/LbNJlNTI2prNNslE6jE30bs8kqk30smI0buud2uxW5Z7krCDF1vJd+BkOPkBYjUjIgm uToYRxBU1lauwf/8NLqTIGi+v/Vjfp/JyiYF8l3oWJ17AVXO0+ay6vBI86abg/weRjA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=P4xVlbEM; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93414606A31E for ; Fri, 30 Oct 2026 12:52:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=P4xVlbEM Received: by smtp.kernel.org (Postfix) with ESMTPSA id 909DA1F00A1A; Fri, 30 Oct 2026 12:52:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793364729; bh=uK3WvoVy0YSvuCfLBv5IV9n4exSO2EGy5EbkcEXAMng=; h=Subject:To:Cc:From:Date; b=P4xVlbEMNGDEk2zrGdqyyRdIc1tfPAA1SnlJdEOzz0JrqVPYYYqegobcQj3uUlTiJ qeyfh86QlRNWP5hogp14dl7OVq9vd5F8EVd+0Mi2ARYb5WDqZp2rpRIfvza2EcTwkH zrtRWSr4PZD9LMq58bG2hR3XFvT6WLJ4bA/upFbQ= Subject: FAILED: patch "[PATCH] net: skbuff: propagate shared-frag marker in skb_zerocopy()" failed to apply to 6.12-stable tree To: pointerliu@126.com,edumazet@kernel.org,kuba@kernel.org Cc: From: Date: Fri, 30 Oct 2026 13:51:55 +0100 Message-ID: <2026103055-regime-lip-8078@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 79dc34beb1fdb3da79753e51e15c68591a2561fe # git commit -s git send-email --to '' --in-reply-to '2026103055-regime-lip-8078@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 79dc34beb1fdb3da79753e51e15c68591a2561fe Mon Sep 17 00:00:00 2001 From: Zizhen Liu Date: Thu, 22 Oct 2026 18:42:17 +0800 Subject: [PATCH] net: skbuff: propagate shared-frag marker in skb_zerocopy() skb_zerocopy() moves frag descriptors from @from into @to and takes a reference on each frag, but it does not copy skb_shinfo(from)->flags into skb_shinfo(to)->flags. A destination skb holding the same page-cache backed frags as the source therefore reports skb_has_shared_frag() as false. That breaks the invariant relied on by later in-place writers. ESP input checks skb_has_shared_frag() before deciding whether an uncloned nonlinear skb can skip skb_cow_data(); with the marker lost, an skb that skb_zerocopy() built for nfnetlink_queue or for an openvswitch upcall is decrypted in place, letting an unprivileged user write into the page cache of a root-owned read-only file. Propagate SKBFL_SHARED_FRAG when frag descriptors are copied, as done for the other frag-transfer helpers. Fixes: af2806f8f90a ("net: Export skb_zerocopy() to zerocopy from one skb to another") Fixes: f4c50a4034e6 ("xfrm: esp: avoid in-place decrypt on shared skb frags") Cc: stable@kernel.org Signed-off-by: Zizhen Liu Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20261022104217.1852191-1-pointerliu@126.com Signed-off-by: Jakub Kicinski diff --git a/net/core/skbuff.c b/net/core/skbuff.c index eb9fcc4b1fd1..6a7c02b7653a 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3966,6 +3966,8 @@ skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen) } skb_shinfo(to)->nr_frags = j; + skb_shinfo(to)->flags |= skb_shinfo(from)->flags & SKBFL_SHARED_FRAG; + if (i > 0 && from->unreadable) to->unreadable = 1;