From patchwork Sat Oct 8 11:49:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fedor Pchelkin X-Patchwork-Id: 614135 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 21698C433F5 for ; Sat, 8 Oct 2022 11:49:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229593AbiJHLt4 (ORCPT ); Sat, 8 Oct 2022 07:49:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229379AbiJHLty (ORCPT ); Sat, 8 Oct 2022 07:49:54 -0400 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48A87193FD; Sat, 8 Oct 2022 04:49:53 -0700 (PDT) Received: from localhost.localdomain (unknown [46.242.14.200]) by mail.ispras.ru (Postfix) with ESMTPSA id 002464077AE4; Sat, 8 Oct 2022 11:49:49 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 002464077AE4 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ispras.ru; s=default; t=1665229790; bh=eGhQBNtLRT/iMFU1ypAtNfUplajfF0B7mQZ1FqvKb6I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OmsIvw93BGjxV+uEf5ZUFZFc5MwdQyTTCo+AYcHXk2UF/PRppEVBUidOkzG2sqKPy gWT/IJbrkjOSfe4NGHUF/VNU5W93l1zjr+UmfvevwkdKICcfvlEYDVMrHUI8GQSlcA W6AkJ8cEXeqT94el3yHCbNHMaEBgUW5T+HP21fME= 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 , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Alexey Khoroshilov , lvc-project@linuxtesting.org Subject: [PATCH v2] ath9k: hif_usb: Fix use-after-free in ath9k_hif_usb_reg_in_cb() Date: Sat, 8 Oct 2022 14:49:17 +0300 Message-Id: <20221008114917.21404-1-pchelkin@ispras.ru> X-Mailer: git-send-email 2.25.1 In-Reply-To: <87ilkvcys7.fsf@toke.dk> References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org It is possible that skb is freed in ath9k_htc_rx_msg(), then usb_submit_urb() fails and we try to free skb again. It causes use-after-free bug. Moreover, if alloc_skb() fails, urb->context becomes NULL but rx_buf is not freed and there can be a memory leak. The patch removes unnecessary nskb and makes skb processing more clear: it is supposed that ath9k_htc_rx_msg() either frees old skb or passes its managing to another callback function. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 3deff76095c4 ("ath9k_htc: Increase URB count for REG_IN pipe") Signed-off-by: Fedor Pchelkin Signed-off-by: Alexey Khoroshilov --- v1->v2: add comment about freeing an skb and remove double blank line drivers/net/wireless/ath/ath9k/hif_usb.c | 28 +++++++++++++----------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c index 4d9002a9d082..401b408cb7a4 100644 --- a/drivers/net/wireless/ath/ath9k/hif_usb.c +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c @@ -708,14 +708,13 @@ static void ath9k_hif_usb_reg_in_cb(struct urb *urb) struct rx_buf *rx_buf = (struct rx_buf *)urb->context; struct hif_device_usb *hif_dev = rx_buf->hif_dev; struct sk_buff *skb = rx_buf->skb; - struct sk_buff *nskb; int ret; if (!skb) return; if (!hif_dev) - goto free; + goto free_skb; switch (urb->status) { case 0: @@ -724,7 +723,7 @@ static void ath9k_hif_usb_reg_in_cb(struct urb *urb) case -ECONNRESET: case -ENODEV: case -ESHUTDOWN: - goto free; + goto free_skb; default: skb_reset_tail_pointer(skb); skb_trim(skb, 0); @@ -735,25 +734,27 @@ static void ath9k_hif_usb_reg_in_cb(struct urb *urb) if (likely(urb->actual_length != 0)) { skb_put(skb, urb->actual_length); - /* Process the command first */ + /* + * Process the command first. + * skb is either freed here or passed to be + * managed to another callback function. + */ ath9k_htc_rx_msg(hif_dev->htc_handle, skb, skb->len, USB_REG_IN_PIPE); - - nskb = alloc_skb(MAX_REG_IN_BUF_SIZE, GFP_ATOMIC); - if (!nskb) { + skb = alloc_skb(MAX_REG_IN_BUF_SIZE, GFP_ATOMIC); + if (!skb) { dev_err(&hif_dev->udev->dev, "ath9k_htc: REG_IN memory allocation failure\n"); - urb->context = NULL; - return; + goto free_rx_buf; } - rx_buf->skb = nskb; + rx_buf->skb = skb; usb_fill_int_urb(urb, hif_dev->udev, usb_rcvintpipe(hif_dev->udev, USB_REG_IN_PIPE), - nskb->data, MAX_REG_IN_BUF_SIZE, + skb->data, MAX_REG_IN_BUF_SIZE, ath9k_hif_usb_reg_in_cb, rx_buf, 1); } @@ -762,12 +763,13 @@ static void ath9k_hif_usb_reg_in_cb(struct urb *urb) ret = usb_submit_urb(urb, GFP_ATOMIC); if (ret) { usb_unanchor_urb(urb); - goto free; + goto free_skb; } return; -free: +free_skb: kfree_skb(skb); +free_rx_buf: kfree(rx_buf); urb->context = NULL; }