From mboxrd@z Thu Jan 1 00:00:00 1970 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 549FEC5479D for ; Tue, 3 Jan 2023 21:03:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233986AbjACVDL (ORCPT ); Tue, 3 Jan 2023 16:03:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231226AbjACVDJ (ORCPT ); Tue, 3 Jan 2023 16:03:09 -0500 Received: from mail.toke.dk (mail.toke.dk [45.145.95.4]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD5252FD; Tue, 3 Jan 2023 13:03:07 -0800 (PST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023; t=1672779785; bh=8XlWB7q8ieR1Skm6kedaC7CKs/VrhNaK24zO4/mpaWc=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=WQD6xWiFOItdmSw8E4C6MmPRZGzaa27UqsPNuxYzUfDtmk5Zv8Wpzfau4VHJptE4q tiLlYS3QEIezMbi4fRG4BcUe4j2SKMDkhF4Mc+rrS9APvCVHKPhTMt5wbFNjbXkixw CbQvAy6iXJdoIQAJXziSwBQEE5BuMnifNzlERhw0MMkRvvI2xD1E//2yhaI4cUdV1B VxfiDEYI1nIeV51lVrPcWaV8qiEoazJysGfA537AEKf3SahNDDmT9usDm/HQTWK+dd TU+OOOyMmeq+iJYPsDLo+RC52OuzHDoKKDtMgd9pltZFStTlgwrfbiU3HgO7djIOAt AqdyHNu9GPSPA== To: Fedor Pchelkin , 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: Re: [PATCH v2] wifi: ath9k: hif_usb: clean up skbs if ath9k_hif_usb_rx_stream() fails In-Reply-To: <20230103143029.273695-1-pchelkin@ispras.ru> References: <20230103143029.273695-1-pchelkin@ispras.ru> Date: Tue, 03 Jan 2023 22:03:05 +0100 X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <875ydn49h2.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Fedor Pchelkin writes: > 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 skb is dropped and all the > associated skb_pool buffers should be cleaned, too. > > 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 > --- > v1->v2: added Reported-by tag > > drivers/net/wireless/ath/ath9k/hif_usb.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c > index 1a2e0c7eeb02..d02cec114280 100644 > --- a/drivers/net/wireless/ath/ath9k/hif_usb.c > +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c > @@ -586,14 +586,14 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev, > > 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); > @@ -654,6 +654,11 @@ 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++) > + kfree_skb(skb_pool[i]); > + return; Hmm, so in the other error cases (if SKB allocation fails), we just 'goto err' and call the receive handler for the packets already in skb_pool. Why can't we do the same here? Also, I think there's another bug in that function, which this change will make worse? Specifically, in the start of that function, hif_dev->remain_skb is moved to skb_pool[0], but not cleared from hif_dev itself. So if we then hit the invalid check and free it, the next time the function is called, we'll get the same remain_skb pointer, which has now been freed. So I think we'll need to clear out hif_dev->remain_skb after moving it to skb_pool. Care to add that as well? -Toke