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 7681937C106; Fri, 4 Sep 2026 05:59:12 +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=1788501553; cv=none; b=JbQzjJbHz9F7G2n9en0f+O7FSDmETm4vWZ5WEp0N8fmmPz5ac1qsUQgMGtBtNdKuXsZ9K0PE0bxmet6QuVffeMMfTf075TVzVSvYHRfCYx+jhbvN20hZJsAzdL+lwr4RoF4CJdOYlYVqSs9ffP2qpql7fCWEG2HOXeif6vUXr5I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501553; c=relaxed/simple; bh=xrSBzBUjUFAFsKC3z+/XthVa3C8H2odglUbLYWluJY0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YunErGuDzuL16IcbMmJWPlRMunrSZ6rHn+1UIRYkpwTklL53WWsAqmIpVIvqGuA8S9UsGFlH8y5zJevvwkgtlaDykMWYpI+LomwZtIin32W8MdJSu/KjczAOjXEiA4TMEkwValX76zeRB/LS0foSErxayuZV2Gq/4+xta9KHtbM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qlOyMBMw; 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="qlOyMBMw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D01081F00A3D; Fri, 4 Sep 2026 05:59:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788501552; bh=CwNhLbpzp9n7fdN/TVm73yi3Cp9K0iUtq7LchQzNOFk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=qlOyMBMwQGlzmBA9SpzY+/6w4GEk8LxtVuo8Z9tFVmzvInvtomsG0YNNp4Unmpeig sxU+l8n28ZBiDnQA+jJ9tciQCdZxNqj4g8a8a4CgtZMvnuhV8Yxpd6ZQ+Pcp4ATOrP BzQI2yYW8NeRoOHppr/YpwypLz+C5o3LCCEjuM7M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiang Mei , Weiming Shi , Jakub Kicinski Subject: [PATCH 6.18 451/552] xdp: fix zero-copy frame layout Date: Fri, 4 Sep 2026 07:00:08 +0200 Message-ID: <20260904045800.930676624@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: Weiming Shi commit 71283aaa6c65b3cec84caf1dc78560985737641f upstream. xdp_convert_zc_to_xdp_frame() clones an XSK packet into an order-0 page and advertises PAGE_SIZE as its frame size. It allows the copied frame to occupy the page tail needed by skb_shared_info and records zero headroom even when metadata separates the frame header from packet data. An AF_XDP zero-copy packet redirected through cpumap can therefore make the skb overlap skb_shared_info or place it beyond the allocated page. Limit the copied layout to SKB_WITH_OVERHEAD(PAGE_SIZE) and include the metadata length in frame headroom. Redirect callers already handle a NULL conversion result. BUG: KASAN: slab-out-of-bounds in skb_gro_receive Write of size 4 at addr ffff88800cf37004 by task cpumap/1/map:1/146 Call Trace: skb_gro_receive (net/core/gro.c:174) udp_gro_receive (net/ipv4/udp_offload.c:812) inet_gro_receive (net/ipv4/af_inet.c:1539) dev_gro_receive (net/core/gro.c:515) gro_receive_skb (net/core/gro.c:633) cpu_map_kthread_run (kernel/bpf/cpumap.c:395) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:164) ret_from_fork_asm (arch/x86/entry/entry_64.S:255) Kernel panic - not syncing: KASAN: panic_on_warn set ... Fixes: b0d1beeff2a9 ("xdp: implement convert_to_xdp_frame for MEM_TYPE_ZERO_COPY") Cc: stable@vger.kernel.org Reported-by: Xiang Mei Signed-off-by: Weiming Shi Link: https://patch.msgid.link/20260818154516.793517-1-bestswngs@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/core/xdp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -585,7 +585,7 @@ struct xdp_frame *xdp_convert_zc_to_xdp_ xdp->data - xdp->data_meta; totsize = xdp->data_end - xdp->data + metasize; - if (sizeof(*xdpf) + totsize > PAGE_SIZE) + if (sizeof(*xdpf) + totsize > SKB_WITH_OVERHEAD(PAGE_SIZE)) return NULL; page = dev_alloc_page(); @@ -602,7 +602,7 @@ struct xdp_frame *xdp_convert_zc_to_xdp_ xdpf->data = addr + metasize; xdpf->len = totsize - metasize; - xdpf->headroom = 0; + xdpf->headroom = metasize; xdpf->metasize = metasize; xdpf->frame_sz = PAGE_SIZE; xdpf->mem_type = MEM_TYPE_PAGE_ORDER0;