From patchwork Tue Aug 16 14:46:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 597830 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 B9A7BC25B0E for ; Tue, 16 Aug 2022 14:46:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235885AbiHPOqe (ORCPT ); Tue, 16 Aug 2022 10:46:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50898 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235664AbiHPOqd (ORCPT ); Tue, 16 Aug 2022 10:46:33 -0400 Received: from www262.sakura.ne.jp (www262.sakura.ne.jp [202.181.97.72]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0ED71647D3 for ; Tue, 16 Aug 2022 07:46:26 -0700 (PDT) Received: from fsav415.sakura.ne.jp (fsav415.sakura.ne.jp [133.242.250.114]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 27GEkGCt018475; Tue, 16 Aug 2022 23:46:16 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav415.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav415.sakura.ne.jp); Tue, 16 Aug 2022 23:46:16 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav415.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 27GEkFcS018451 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Tue, 16 Aug 2022 23:46:16 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Message-ID: <7acfa1be-4b5c-b2ce-de43-95b0593fb3e5@I-love.SAKURA.ne.jp> Date: Tue, 16 Aug 2022 23:46:13 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.1.2 Subject: [PATCH v2] ath9k: avoid uninit memory read in ath9k_htc_rx_msg() Content-Language: en-US To: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Kalle Valo Cc: linux-wireless References: <000000000000c98a7f05ac744f53@google.com> <87edxgwarp.fsf@toke.dk> From: Tetsuo Handa In-Reply-To: <87edxgwarp.fsf@toke.dk> Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org syzbot is reporting uninit value at ath9k_htc_rx_msg() [1], for ioctl(USB_RAW_IOCTL_EP_WRITE) can call ath9k_hif_usb_rx_stream() with pkt_len = 0 but ath9k_hif_usb_rx_stream() uses __dev_alloc_skb(pkt_len + 32, GFP_ATOMIC) based on an assumption that pkt_len is valid. As a result, ath9k_hif_usb_rx_stream() allocates skb with uninitialized memory and ath9k_htc_rx_msg() is reading from uninitialized memory. Since bytes accessed by ath9k_htc_rx_msg() is not known until ath9k_htc_rx_msg() is called, it would be difficult to check minimal valid pkt_len at "if (pkt_len > 2 * MAX_RX_BUF_SIZE) {" line in ath9k_hif_usb_rx_stream(). We have two choices. One is to workaround by adding __GFP_ZERO so that ath9k_htc_rx_msg() sees 0 if pkt_len is invalid. The other is to let ath9k_htc_rx_msg() validate pkt_len before accessing. This patch chose the latter. Note that I'm not sure threshold condition is correct, for I can't find details on possible packet length used by this protocol. Link: https://syzkaller.appspot.com/bug?extid=2ca247c2d60c7023de7f [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Acked-by: Toke Høiland-Jørgensen --- Changes in v2: Update patch description. drivers/net/wireless/ath/ath9k/htc_hst.c | 43 +++++++++++++++--------- 1 file changed, 28 insertions(+), 15 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c index 994ec48b2f66..ca05b07a45e6 100644 --- a/drivers/net/wireless/ath/ath9k/htc_hst.c +++ b/drivers/net/wireless/ath/ath9k/htc_hst.c @@ -364,33 +364,27 @@ void ath9k_htc_txcompletion_cb(struct htc_target *htc_handle, } static void ath9k_htc_fw_panic_report(struct htc_target *htc_handle, - struct sk_buff *skb) + struct sk_buff *skb, u32 len) { uint32_t *pattern = (uint32_t *)skb->data; - switch (*pattern) { - case 0x33221199: - { + if (*pattern == 0x33221199 && len >= sizeof(struct htc_panic_bad_vaddr)) { struct htc_panic_bad_vaddr *htc_panic; htc_panic = (struct htc_panic_bad_vaddr *) skb->data; dev_err(htc_handle->dev, "ath: firmware panic! " "exccause: 0x%08x; pc: 0x%08x; badvaddr: 0x%08x.\n", htc_panic->exccause, htc_panic->pc, htc_panic->badvaddr); - break; - } - case 0x33221299: - { + return; + } + if (*pattern == 0x33221299) { struct htc_panic_bad_epid *htc_panic; htc_panic = (struct htc_panic_bad_epid *) skb->data; dev_err(htc_handle->dev, "ath: firmware panic! " "bad epid: 0x%08x\n", htc_panic->epid); - break; - } - default: - dev_err(htc_handle->dev, "ath: unknown panic pattern!\n"); - break; + return; } + dev_err(htc_handle->dev, "ath: unknown panic pattern!\n"); } /* @@ -411,16 +405,26 @@ void ath9k_htc_rx_msg(struct htc_target *htc_handle, if (!htc_handle || !skb) return; + /* A valid message requires len >= 8. + * + * sizeof(struct htc_frame_hdr) == 8 + * sizeof(struct htc_ready_msg) == 8 + * sizeof(struct htc_panic_bad_vaddr) == 16 + * sizeof(struct htc_panic_bad_epid) == 8 + */ + if (unlikely(len < sizeof(struct htc_frame_hdr))) + goto invalid; htc_hdr = (struct htc_frame_hdr *) skb->data; epid = htc_hdr->endpoint_id; if (epid == 0x99) { - ath9k_htc_fw_panic_report(htc_handle, skb); + ath9k_htc_fw_panic_report(htc_handle, skb, len); kfree_skb(skb); return; } if (epid < 0 || epid >= ENDPOINT_MAX) { +invalid: if (pipe_id != USB_REG_IN_PIPE) dev_kfree_skb_any(skb); else @@ -432,21 +436,30 @@ void ath9k_htc_rx_msg(struct htc_target *htc_handle, /* Handle trailer */ if (htc_hdr->flags & HTC_FLAGS_RECV_TRAILER) { - if (be32_to_cpu(*(__be32 *) skb->data) == 0x00C60000) + if (be32_to_cpu(*(__be32 *) skb->data) == 0x00C60000) { /* Move past the Watchdog pattern */ htc_hdr = (struct htc_frame_hdr *)(skb->data + 4); + len -= 4; + } } /* Get the message ID */ + if (unlikely(len < sizeof(struct htc_frame_hdr) + sizeof(__be16))) + goto invalid; msg_id = (__be16 *) ((void *) htc_hdr + sizeof(struct htc_frame_hdr)); /* Now process HTC messages */ switch (be16_to_cpu(*msg_id)) { case HTC_MSG_READY_ID: + if (unlikely(len < sizeof(struct htc_ready_msg))) + goto invalid; htc_process_target_rdy(htc_handle, htc_hdr); break; case HTC_MSG_CONNECT_SERVICE_RESPONSE_ID: + if (unlikely(len < sizeof(struct htc_frame_hdr) + + sizeof(struct htc_conn_svc_rspmsg))) + goto invalid; htc_process_conn_rsp(htc_handle, htc_hdr); break; default: