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=1793364735; b=o94PCDUqMcuQM/yrlkIT8SOBW/FnQIInFTZQ8fkNkemOpBv3t0vB20toTrTEuVfC76ra jw5wjYPbs5PARWwO0Aebw2crdKc4O3rx82bUi5pdpBhWboCrlkbPTnvf6hs+gssHF8x0j xEh2nYiuiEibm+B7LXewneV1/MwTfKpu4yxxek/BErMfCFNdVHB9BJjW2ptMuiY0lRy7a pcZQrNKI0W74U2uLEdyryy8D0u79Fa3xBubuOtNJQhptvKtvRhQHBj9vFfYPWfwZ/pPGe CgA+sS5vlx7c4nRUbzKbIsk4lvh1lozi+N8qdS2qsOu6q4xiT7j10Zb9Q0RTK2hAXyw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793364735; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=oNBysJGgP/TF702ENbCC5T1wO6Q5gBtZKUg73KFvsOQ=; b=mIH6uhCvaX4onKMWcIXxVwccTy2TClc7zGxyviKCsrQ731ktLEq++AbTsqtWQpmLuXuH bxxnu9u8N5dMHktU+LHUzsHgBaX9FIb/yePmXZNsqGtAT57Pj+L3KxqKw4lA76jAYD5RO jD7ye0c7DmnX3h2ngnnEcHsNTwwlLQgZVEzBfRCPALFLM1JrCJxKHAkEJZDRZsaM6NRJK 6uU4YCS96F/p+Lc5ez56eVm7GsYKsZUsaAchHIXdAIMHHsAQoTlDYq/21CBY8QQTSC4VW XrCE9pjy+svxD3sATP7Fc96xOl6fXOaeErLvBzmFQDyIn3B+b+wNFk44SHcSVSIhU6Q== 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=FJlIvfcs; 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 67EAF606A333 for ; Fri, 30 Oct 2026 12:52:15 +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=FJlIvfcs Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91FB61F00A1F; Fri, 30 Oct 2026 12:52:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793364735; bh=oNBysJGgP/TF702ENbCC5T1wO6Q5gBtZKUg73KFvsOQ=; h=Subject:To:Cc:From:Date; b=FJlIvfcsWPAqm56dsb+tD/ENigbkXlIM8ZRfSGUwnZ59kYlaDfqZqMWY95ljZbKtY jqzX131XyJ6Vr/jd0okYfl3EcrDTUdE6pJpqw8KXTDZHnrNyUGWZLYPZLk9kbQbTZ/ 4qrCi44bIq8chAbrimriiHyFFM6jE/u1fpmJzkgc= Subject: FAILED: patch "[PATCH] net: skbuff: propagate shared-frag marker in skb_zerocopy()" failed to apply to 6.6-stable tree To: pointerliu@126.com,edumazet@kernel.org,kuba@kernel.org Cc: From: Date: Fri, 30 Oct 2026 13:51:56 +0100 Message-ID: <2026103056-slug-alibi-45b6@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 6.6-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-6.6.y git checkout FETCH_HEAD git cherry-pick -x 79dc34beb1fdb3da79753e51e15c68591a2561fe # git commit -s git send-email --to '' --in-reply-to '2026103056-slug-alibi-45b6@gregkh' --subject-prefix 'PATCH 6.6.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;