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 AA00FC4332F for ; Sun, 18 Dec 2022 16:59:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233145AbiLRQ71 (ORCPT ); Sun, 18 Dec 2022 11:59:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233248AbiLRQ5n (ORCPT ); Sun, 18 Dec 2022 11:57:43 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B32651CB0E; Sun, 18 Dec 2022 08:20:11 -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 574F6B80BA7; Sun, 18 Dec 2022 16:20:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10317C433EF; Sun, 18 Dec 2022 16:20:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671380409; bh=iTuO9QfbW5dOdxV+MuKHqJvpops+DbnddqpcwT5+1hA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TsFVx+Ybf5MJGxb+ND5drw4oNY0OgSB8I4CC65WpdA+sL1VcVngMrnFOE27Qu2pYs iNgsJHRfzbVXgBFIMEvJVJlQLndS1R5tg5+Sna12EidWyEOAo9xiZuf2Al34VST2ua HWhb2ImLKQ45+wX1p6Inx5n/YDXgW5ZdZ0CYPnoYKbfh89++w5zqJz/VUsKutxX6KE zbNKQzit5Ot7ghpIgclqn10goWfT6Ukzu0wZUr1GY9Dr/UoPlQGKoHpYgfSUVE7kN0 2tF+rzz5156kF7ZFZ99Te4anj+WWQbNFwTibzTQdZt3qGUJqP1QuzelsMa4kObIqNT yiBpYRQ28rxZg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Shigeru Yoshida , syzbot+9ca7a12fd736d93e0232@syzkaller.appspotmail.com, Hans Verkuil , Sasha Levin , hverkuil@xs4all.nl, mchehab@kernel.org, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 29/30] media: si470x: Fix use-after-free in si470x_int_in_callback() Date: Sun, 18 Dec 2022 11:18:34 -0500 Message-Id: <20221218161836.933697-29-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218161836.933697-1-sashal@kernel.org> References: <20221218161836.933697-1-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-kernel@vger.kernel.org From: Shigeru Yoshida [ Upstream commit 7d21e0b1b41b21d628bf2afce777727bd4479aa5 ] syzbot reported use-after-free in si470x_int_in_callback() [1]. This indicates that urb->context, which contains struct si470x_device object, is freed when si470x_int_in_callback() is called. The cause of this issue is that si470x_int_in_callback() is called for freed urb. si470x_usb_driver_probe() calls si470x_start_usb(), which then calls usb_submit_urb() and si470x_start(). If si470x_start_usb() fails, si470x_usb_driver_probe() doesn't kill urb, but it just frees struct si470x_device object, as depicted below: si470x_usb_driver_probe() ... si470x_start_usb() ... usb_submit_urb() retval = si470x_start() return retval if (retval < 0) free struct si470x_device object, but don't kill urb This patch fixes this issue by killing urb when si470x_start_usb() fails and urb is submitted. If si470x_start_usb() fails and urb is not submitted, i.e. submitting usb fails, it just frees struct si470x_device object. Reported-by: syzbot+9ca7a12fd736d93e0232@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=94ed6dddd5a55e90fd4bab942aa4bb297741d977 [1] Signed-off-by: Shigeru Yoshida Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/radio/si470x/radio-si470x-usb.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/media/radio/si470x/radio-si470x-usb.c b/drivers/media/radio/si470x/radio-si470x-usb.c index 3f8634a46573..1365ae732b79 100644 --- a/drivers/media/radio/si470x/radio-si470x-usb.c +++ b/drivers/media/radio/si470x/radio-si470x-usb.c @@ -733,8 +733,10 @@ static int si470x_usb_driver_probe(struct usb_interface *intf, /* start radio */ retval = si470x_start_usb(radio); - if (retval < 0) + if (retval < 0 && !radio->int_in_running) goto err_buf; + else if (retval < 0) /* in case of radio->int_in_running == 1 */ + goto err_all; /* set initial frequency */ si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */ -- 2.35.1