From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp9.goneo.de (smtp9.goneo.de [85.220.189.104]) (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 869EA4DB56C; Fri, 5 Jun 2026 12:14:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=85.220.189.104 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780661697; cv=none; b=LS2anf4N0TLVs22GjqJSmIYRhpBZ3g1mKiIfpQbfdDjnP8VlH0/uXeXHNhAiIBKMGcFqChw9duRdKkly9+KZrzszyf63cZ/q7PClgX1vsBtfF/HBwQu60QNOoqaFYuypF+9rIX8HKfIbyNrUlB9L1tlPHUQe/j0u03xi+fIAuyQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780661697; c=relaxed/simple; bh=2no5ts4uR+BRFpbAeaMDuXoBtDm87qzy992Y6dadpc8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XIKqVOIZtHDT4OVRz2nw8bppk58HIck0mT8Jp/deWF497tBzLdrCvScfXn8HNVFS51ca4dLpSfGC/DN0gr8ZXsYb/nWnLDmFeKeWJDrtq1u3mLwmQL+xXcgbhQjwTKI1iE7fs9dyn9/kfFCzO9pqYsSUgzgsFJglKJFkY6k0ZzY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tk154.de; spf=pass smtp.mailfrom=tk154.de; dkim=pass (2048-bit key) header.d=tk154.de header.i=@tk154.de header.b=ItmxyC1o; arc=none smtp.client-ip=85.220.189.104 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tk154.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tk154.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tk154.de header.i=@tk154.de header.b="ItmxyC1o" Received: from hub2.goneo.de (hub2.goneo.de [IPv6:2001:1640:5::8:53]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519) (No client certificate requested) by smtp9.goneo.de (Postfix) with ESMTPS id D44662403E9; Fri, 05 Jun 2026 14:14:47 +0200 (CEST) Received: from hub2.goneo.de (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by hub2.goneo.de (Postfix) with ESMTPS id 3D946240511; Fri, 5 Jun 2026 14:14:46 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tk154.de; s=DKIM001; t=1780661686; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=C1Ioe8uKiJIxbIqpXcCQ8i5GRjn3ORGyOB/YwWZ/fog=; b=ItmxyC1oPSLgLXvUw5IjRgR11LcQQJFnmDuEKng82XAxd+7v65sBc+HvcPkfMUcxxPPzA7 LaHmMQJDXobOCNJMIErw3wECu/hY1jxhJRpNS4pwZ40wMrkegjDtvzfbycDxXt9of884IR o3XGJ9xS/rzezdTAVR46+DkiqASgl2A7wUzK1Wz7ACdmRchYI4WfxUgixbN9U7nuQnIDaJ lJT7qG2wN9exT2We5MS+H5/bOrS3rQCMag4bCAVUJjROdeN5rST51U1XmUfR26z/Zflmsk xIZa20FLpqD3ApszF9dpPeL6eSq4byVXKqp70dXpCmzWxGzR+OCeSaI0rxyqyQ== Received: from Til-Notebook.meshlab (unknown [195.37.88.189]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by hub2.goneo.de (Postfix) with ESMTPSA id 1B72324035A; Fri, 5 Jun 2026 14:14:44 +0200 (CEST) From: Til Kaiser To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: marcin.s.wojtas@gmail.com, linux@armlinux.org.uk, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, sdf@fomichev.me, mcroce@redhat.com, sven.auhagen@voleatech.de, lorenzo@kernel.org, Til Kaiser Subject: [PATCH net v3 2/4] net: mvpp2: limit XDP frame size to the RX buffer Date: Fri, 5 Jun 2026 14:13:30 +0200 Message-ID: <20260605121332.147397-3-mail@tk154.de> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260605121332.147397-1-mail@tk154.de> References: <20260602164635.62517-1-mail@tk154.de> <20260605121332.147397-1-mail@tk154.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-UID: cdc45f X-Rspamd-UID: 6158c8 mvpp2 has short and long BM pools, and short pool buffers can be smaller than PAGE_SIZE. The XDP path nevertheless initializes every xdp_buff with PAGE_SIZE as frame size. XDP helpers use frame_sz to validate tail growth and to derive the hard end of the data area. Advertising PAGE_SIZE for short buffers can let bpf_xdp_adjust_tail() grow a packet past the real allocation, corrupting memory or later tripping skb tailroom checks. Initialize the XDP buffer with bm_pool->frag_size so XDP tailroom matches the actual buffer backing the packet. Fixes: 07dd0a7aae7f ("mvpp2: add basic XDP support") Signed-off-by: Til Kaiser --- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 92a701f4fe3f..3372ed27cc8d 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3979,7 +3979,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, else xdp_rxq = &rxq->xdp_rxq_long; - xdp_init_buff(&xdp, PAGE_SIZE, xdp_rxq); + xdp_init_buff(&xdp, bm_pool->frag_size, xdp_rxq); xdp_prepare_buff(&xdp, data, MVPP2_MH_SIZE + MVPP2_SKB_HEADROOM, rx_bytes, true); -- 2.54.0