From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.smtp-ext.broadcom.com (relay.smtp-ext.broadcom.com [192.19.166.231]) (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 03E764756BB; Mon, 21 Sep 2026 23:14:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.19.166.231 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790032483; cv=none; b=Q7fnKK/lMXWGsKN59pzGyBqJ5/3nWFASu2+U5NzIfaVK9fagMRMvmG3lwyZIpkqF59uivtFHvVZ5FH3sKPltsxdg18DRyvHxPssW+pEq8a5uoPvPjhQDkW5cEaV8Es7KFtznWmEXlr6d73Y1la2mvzkYlMswShlW8gb7SMvVnro= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790032483; c=relaxed/simple; bh=4KHTSHt2fx+tQth8nGkiLtxWijpx7L69RbtnLLBuXtY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=tpeMSCJKCdvjgcFQmanzV6bUGcnr22U6IpkzIc9xJo5OPJ/vJRc/9o93cbEgdZWPxnRZutw38fuu/n4tvHikb4NZuWcNH6ab/sNzD+i1XRkH+jCv4kvfh9MbIEEONecF8I4ZqCBY0BjITZr751rDsmGIJsbuA0DN0vUg8OYl6vU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=broadcom.com; spf=fail smtp.mailfrom=broadcom.com; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b=GvTFIYO9; arc=none smtp.client-ip=192.19.166.231 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=broadcom.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=broadcom.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="GvTFIYO9" Received: from mail-lvn-it-01.broadcom.com (mail-lvn-it-01.lvn.broadcom.net [10.36.132.253]) by relay.smtp-ext.broadcom.com (Postfix) with ESMTP id 79505C000D85; Mon, 21 Sep 2026 16:14:33 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 relay.smtp-ext.broadcom.com 79505C000D85 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=broadcom.com; s=dkimrelay; t=1790032473; bh=4KHTSHt2fx+tQth8nGkiLtxWijpx7L69RbtnLLBuXtY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GvTFIYO9fJJU2kNdEBAfhMj1XC2nD8Jyvad51d9vAqfllje61OTjku7vJkG081kEn 2WhwKy9sqdjpQm+AzRvrIVgBrDneBqhIo3DNpomoPuTzuAWNoi6029Mv723RLNBdTA TZjHznix8mmpbi5aHygO6zvhml9yaSou9Dxvrkx4= Received: from stbirv-lnx-1.igp.broadcom.net (stbirv-lnx-1.igp.broadcom.net [10.67.48.32]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail-lvn-it-01.broadcom.com (Postfix) with ESMTPSA id 564E1AD9; Mon, 21 Sep 2026 16:14:33 -0700 (PDT) From: Florian Fainelli To: netdev@vger.kernel.org Cc: Florian Fainelli , Doug Berger , Broadcom internal kernel review list , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Zak Kemble , Simon Horman , Ryo Takakura , linux-kernel@vger.kernel.org (open list), Nicolai Buchwitz Subject: [PATCH net 07/12] net: systemport: Fix potential packet length underflow in bcm_sysport_desc_rx() Date: Mon, 21 Sep 2026 16:13:00 -0700 Message-Id: <20260921231305.394773-8-florian.fainelli@broadcom.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260921231305.394773-1-florian.fainelli@broadcom.com> References: <20260921231305.394773-1-florian.fainelli@broadcom.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit In bcm_sysport_desc_rx(), the packet length 'len' extracted from the RSB is only validated against RX_BUF_LENGTH. If a malformed or corrupted frame is received with 'len' smaller than the prepended Receive Status Block (sizeof(*rsb)) plus 2 padding bytes (and optional FCS), calling skb_pull() will trigger a BUG() in __skb_pull() when pulling beyond skb->len. Furthermore, subtracting (sizeof(*rsb) + 2) from 'len' (u16) will underflow, resulting in corrupted packet stats and potential out-of-bounds operations. Fix this by ensuring 'len' is at least sizeof(*rsb) + 2 (plus ETH_FCS_LEN if CRC forward is enabled) before proceeding. Fixes: 80105befdb4b ("net: systemport: add Broadcom SYSTEMPORT Ethernet MAC driver") Assisted-by: LLM Signed-off-by: Florian Fainelli --- drivers/net/ethernet/broadcom/bcmsysport.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index b69833d34bd5..95cead1df160 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -781,8 +781,9 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv, p_index, priv->rx_c_index, priv->rx_read_ptr, len, status); - if (unlikely(len > RX_BUF_LENGTH)) { - netif_err(priv, rx_status, ndev, "oversized packet\n"); + if (unlikely(len > RX_BUF_LENGTH || + len < sizeof(*rsb) + 2 + (priv->crc_fwd ? ETH_FCS_LEN : 0))) { + netif_err(priv, rx_status, ndev, "invalid packet size: %d\n", len); ndev->stats.rx_length_errors++; ndev->stats.rx_errors++; dev_kfree_skb_any(skb); -- 2.34.1