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 EEC493E639D; Tue, 13 Oct 2026 12:23:24 +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=1791894206; cv=none; b=InDesA1R1fyZbMZvdqP8wZPNzOafV053i+j5HUGTWQrq17j3fPobFCXfE3XkunxKhvPWEQTUWmHq5kptVTEjv4OEQouAjZNWIMF/gyk7AvqH7moqGQP+H4H1xSpPW7Kb4R8//uGtGAS0f4nWFvno3QBOebMk+AEq0bkurII96b0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791894206; c=relaxed/simple; bh=QxJngNYSpoTt+S7brdodwYKqSe9PGNLPxhKuUC0BNHE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VVMplhKdeARLtaXTNyVGCoQ24HAroT/DPnI1+OqE6q3l/GpRtWdi4RuU/SF/S18RSz7uapZOTooj9Ep07qSPsUdXYewRxi1zNRetjnaQqHx1j7HVhd++/rpH07wb0/s8eje4ykSMdiskPjU1Pewotmk5JtE194q0fCgtoSKYz3o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=z7cuThU6; 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="z7cuThU6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4FFAB1F000FF; Tue, 13 Oct 2026 12:23:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791894204; bh=iHbkfBoRl6HXqaQIln6xDJ3qECtbk8Q0QA6gnYA32ag=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=z7cuThU6cyrZk4rV09ak+2I3Tdt9ZcSfdmByqpJZuCYadsA9oPb8b2bxy6fdFhVnf Dqwu+IpxjN7/zA8/wYT6RvV86XQ7VcW5S5vj2181V9tkHPzEFxp62aRqZMhXf5rbuw igae3tm30QfKIDtFKzAok3dX/EtO4UFCbsXf0Yk0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Maher Azzouzi , Steffen Klassert , Sasha Levin Subject: [PATCH 6.18 480/621] esp: do not unref managed frag pages in esp_ssg_unref() Date: Tue, 13 Oct 2026 13:37:55 +0200 Message-ID: <20261013112932.224044218@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112920.855194808@linuxfoundation.org> References: <20261013112920.855194808@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: Maher Azzouzi [ Upstream commit 21697720ff43b8dfa25b8e8d9ca7f56f4597fc80 ] esp_ssg_unref() releases the page references held on the source scatterlist after the AEAD operation completes. It calls skb_page_unref() on every frag page for an out-of-place transform (req->src != req->dst), and in the error path of esp_output_tail() (already_unref == true) on the request's own scatterlist. This is wrong when the skb carries managed frags (SKBFL_MANAGED_FRAG_REFS). Managed frags are owned by a zerocopy ubuf and the skb does not hold a per-frag page reference; io_uring SEND_ZC with a registered buffer attaches the bvec pages this way via io_sg_from_iter(). The rest of the stack honours this invariant: skb_release_data() skips the per-frag unref when SKBFL_MANAGED_FRAG_REFS is set, and skb_zcopy_managed() is the guard used at the other unref sites. esp_ssg_unref() is missing that guard, so for a managed-frag skb it drops a page reference the skb never acquired. This can underflow the page reference count and free a page that is still in use. Guard the function with skb_zcopy_managed() so both unref paths are skipped for managed-frag skbs, matching skb_release_data(). Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Signed-off-by: Maher Azzouzi Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/ipv4/esp4.c | 7 +++++++ net/ipv6/esp6.c | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 346e78c23af00..53284524cf4f4 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -104,6 +104,13 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb) struct aead_request *req; struct scatterlist *sg; + /* Managed frags are owned by the zerocopy ubuf; the skb holds no + * per-frag page reference, so we must not drop one here. Mirrors + * the SKBFL_MANAGED_FRAG_REFS handling in skb_release_data(). + */ + if (skb_zcopy_managed(skb)) + return; + if (x->props.flags & XFRM_STATE_ESN) extralen += sizeof(struct esp_output_extra); diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index b26b85afb92ed..2f19ff51ab3df 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -121,6 +121,13 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb) struct aead_request *req; struct scatterlist *sg; + /* Managed frags are owned by the zerocopy ubuf; the skb holds no + * per-frag page reference, so we must not drop one here. Mirrors + * the SKBFL_MANAGED_FRAG_REFS handling in skb_release_data(). + */ + if (skb_zcopy_managed(skb)) + return; + if (x->props.flags & XFRM_STATE_ESN) extralen += sizeof(struct esp_output_extra); -- 2.53.0