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 09442C3526D for ; Tue, 18 Jan 2022 03:16:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356471AbiARDQX (ORCPT ); Mon, 17 Jan 2022 22:16:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39802 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348884AbiARDIF (ORCPT ); Mon, 17 Jan 2022 22:08:05 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB1BFC033278; Mon, 17 Jan 2022 18:49:16 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7FCE6B8123F; Tue, 18 Jan 2022 02:49:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B33BC36AE3; Tue, 18 Jan 2022 02:49:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642474154; bh=Rl+seFCLIEA6ePAQhBWREbLa9pE10jUp93g1f8T3wvk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JeDz6yH3p8OTDAnw3bEvCErzbza99TMXnrZNU6ucHDvAsysqHoO3J1OFhfpLjmsU9 F2mOm1PoO4BUpwShOcniXoiDScWpctvXgnzQhwd00c8rXdQ83O75eX2a8H94P0zair Jyc6dA8iKsokAQkwTTDbOiyEdtlFvPDdmpHjbPDUArMUvz8UKB8zRxKu+ry8QSdno1 awqQ6HOCahwr7hSScHQOXZmtBovW0pGaHDE490oERz8XdV1C9faNQV0XzP/MUMYilA z63QjcU3+UXufVuxPNN6a2aLrWbp9HpKlYF1iRSYE63r/nqQG65dxZcfOMfSARvLPn GX9MO8cwVzAVA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zekun Shen , Kalle Valo , Sasha Levin , pontus.fuchs@gmail.com, kvalo@kernel.org, davem@davemloft.net, kuba@kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 03/56] ar5523: Fix null-ptr-deref with unexpected WDCMSG_TARGET_START reply Date: Mon, 17 Jan 2022 21:48:15 -0500 Message-Id: <20220118024908.1953673-3-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118024908.1953673-1-sashal@kernel.org> References: <20220118024908.1953673-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Zekun Shen [ Upstream commit ae80b6033834342601e99f74f6a62ff5092b1cee ] Unexpected WDCMSG_TARGET_START replay can lead to null-ptr-deref when ar->tx_cmd->odata is NULL. The patch adds a null check to prevent such case. KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] ar5523_cmd+0x46a/0x581 [ar5523] ar5523_probe.cold+0x1b7/0x18da [ar5523] ? ar5523_cmd_rx_cb+0x7a0/0x7a0 [ar5523] ? __pm_runtime_set_status+0x54a/0x8f0 ? _raw_spin_trylock_bh+0x120/0x120 ? pm_runtime_barrier+0x220/0x220 ? __pm_runtime_resume+0xb1/0xf0 usb_probe_interface+0x25b/0x710 really_probe+0x209/0x5d0 driver_probe_device+0xc6/0x1b0 device_driver_attach+0xe2/0x120 I found the bug using a custome USBFuzz port. It's a research work to fuzz USB stack/drivers. I modified it to fuzz ath9k driver only, providing hand-crafted usb descriptors to QEMU. After fixing the code (fourth byte in usb packet) to WDCMSG_TARGET_START, I got the null-ptr-deref bug. I believe the bug is triggerable whenever cmd->odata is NULL. After patching, I tested with the same input and no longer see the KASAN report. This was NOT tested on a real device. Signed-off-by: Zekun Shen Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/YXsmPQ3awHFLuAj2@10-18-43-117.dynapool.wireless.nyu.edu Signed-off-by: Sasha Levin --- drivers/net/wireless/ath/ar5523/ar5523.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c index e1a1d27427cc9..bf43244f051c5 100644 --- a/drivers/net/wireless/ath/ar5523/ar5523.c +++ b/drivers/net/wireless/ath/ar5523/ar5523.c @@ -153,6 +153,10 @@ static void ar5523_cmd_rx_cb(struct urb *urb) ar5523_err(ar, "Invalid reply to WDCMSG_TARGET_START"); return; } + if (!cmd->odata) { + ar5523_err(ar, "Unexpected WDCMSG_TARGET_START reply"); + return; + } memcpy(cmd->odata, hdr + 1, sizeof(u32)); cmd->olen = sizeof(u32); cmd->res = 0; -- 2.34.1