From patchwork Wed Jan 4 12:36:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Fedor Pchelkin X-Patchwork-Id: 639216 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 317DFC4708E for ; Wed, 4 Jan 2023 12:37:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239191AbjADMhE (ORCPT ); Wed, 4 Jan 2023 07:37:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239277AbjADMgg (ORCPT ); Wed, 4 Jan 2023 07:36:36 -0500 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D235813CDF; Wed, 4 Jan 2023 04:36:35 -0800 (PST) Received: from fedcomp.. (unknown [46.242.14.200]) by mail.ispras.ru (Postfix) with ESMTPSA id 466DD419E9F5; Wed, 4 Jan 2023 12:36:34 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 466DD419E9F5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ispras.ru; s=default; t=1672835794; bh=dc0S1ZC+JXp9Z/sCIUJ7rKnBqUvmEKO7DJxlv7hastk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PB7Z2vnPjVQVqjLXOkVkz0W94WO0xFb1hYlDUFOdlbFTlSr+3TAyaLfo5acwMgkeo IMlbDPynh//gP+nQSxqYj6CdAt3l6kho4vO2i62xBesNW+DHA0HnlWijvWj/OnQRn1 LISAdoTGbvZDemANeyr1p/uPXul7+CDHEKUnRa10= From: Fedor Pchelkin To: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Kalle Valo Cc: Fedor Pchelkin , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Zekun Shen , Joe Perches , "John W. Linville" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Alexey Khoroshilov , lvc-project@linuxtesting.org, syzbot+e9632e3eb038d93d6bc6@syzkaller.appspotmail.com Subject: [PATCH v3] wifi: ath9k: hif_usb: clean up skbs if ath9k_hif_usb_rx_stream() fails Date: Wed, 4 Jan 2023 15:36:15 +0300 Message-Id: <20230104123615.51511-1-pchelkin@ispras.ru> X-Mailer: git-send-email 2.34.1 In-Reply-To: <87tu172np9.fsf@toke.dk> References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Syzkaller detected a memory leak of skbs in ath9k_hif_usb_rx_stream(). While processing skbs in ath9k_hif_usb_rx_stream(), the already allocated skbs in skb_pool are not freed if ath9k_hif_usb_rx_stream() fails. If we have an incorrect pkt_len or pkt_tag, the input skb is considered invalid and dropped. All the associated packets already in skb_pool should be dropped and freed. Added a comment describing this issue. The patch also makes remain_skb NULL after being processed so that it cannot be referenced after potential free. The initialization of hif_dev fields which are associated with remain_skb (rx_remain_len, rx_transfer_len and rx_pad_len) is moved after a new remain_skb is allocated. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 6ce708f54cc8 ("ath9k: Fix out-of-bound memcpy in ath9k_hif_usb_rx_stream") Fixes: 44b23b488d44 ("ath9k: hif_usb: Reduce indent 1 column") Reported-by: syzbot+e9632e3eb038d93d6bc6@syzkaller.appspotmail.com Signed-off-by: Fedor Pchelkin Signed-off-by: Alexey Khoroshilov Acked-by: Toke Høiland-Jørgensen --- v1->v2: added Reported-by tag v2->v3: added proper remain_skb processing, stat macro, comment drivers/net/wireless/ath/ath9k/hif_usb.c | 31 +++++++++++++++++------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c index 1a2e0c7eeb02..de6c0824c9ca 100644 --- a/drivers/net/wireless/ath/ath9k/hif_usb.c +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c @@ -561,11 +561,11 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev, memcpy(ptr, skb->data, rx_remain_len); rx_pkt_len += rx_remain_len; - hif_dev->rx_remain_len = 0; skb_put(remain_skb, rx_pkt_len); skb_pool[pool_index++] = remain_skb; - + hif_dev->remain_skb = NULL; + hif_dev->rx_remain_len = 0; } else { index = rx_remain_len; } @@ -584,16 +584,21 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev, pkt_len = get_unaligned_le16(ptr + index); pkt_tag = get_unaligned_le16(ptr + index + 2); + /* It is supposed that if we have an invalid pkt_tag or + * pkt_len then the whole input SKB is considered invalid + * and dropped; the associated packets already in skb_pool + * are dropped, too. + */ if (pkt_tag != ATH_USB_RX_STREAM_MODE_TAG) { RX_STAT_INC(hif_dev, skb_dropped); - return; + goto invalid_pkt; } if (pkt_len > 2 * MAX_RX_BUF_SIZE) { dev_err(&hif_dev->udev->dev, "ath9k_htc: invalid pkt_len (%x)\n", pkt_len); RX_STAT_INC(hif_dev, skb_dropped); - return; + goto invalid_pkt; } pad_len = 4 - (pkt_len & 0x3); @@ -605,11 +610,6 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev, if (index > MAX_RX_BUF_SIZE) { spin_lock(&hif_dev->rx_lock); - hif_dev->rx_remain_len = index - MAX_RX_BUF_SIZE; - hif_dev->rx_transfer_len = - MAX_RX_BUF_SIZE - chk_idx - 4; - hif_dev->rx_pad_len = pad_len; - nskb = __dev_alloc_skb(pkt_len + 32, GFP_ATOMIC); if (!nskb) { dev_err(&hif_dev->udev->dev, @@ -617,6 +617,12 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev, spin_unlock(&hif_dev->rx_lock); goto err; } + + hif_dev->rx_remain_len = index - MAX_RX_BUF_SIZE; + hif_dev->rx_transfer_len = + MAX_RX_BUF_SIZE - chk_idx - 4; + hif_dev->rx_pad_len = pad_len; + skb_reserve(nskb, 32); RX_STAT_INC(hif_dev, skb_allocated); @@ -654,6 +660,13 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev, skb_pool[i]->len, USB_WLAN_RX_PIPE); RX_STAT_INC(hif_dev, skb_completed); } + return; +invalid_pkt: + for (i = 0; i < pool_index; i++) { + dev_kfree_skb_any(skb_pool[i]); + RX_STAT_INC(hif_dev, skb_dropped); + } + return; } static void ath9k_hif_usb_rx_cb(struct urb *urb)