From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2E77613D24D; Thu, 11 Apr 2024 10:38:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712831895; cv=none; b=cKIvNX1pBv+I4fakWuwFk52IUmsGzu4BdWjlpYautkp6LQc/ZczndgpE6jrDsyHo+KB/t6nFjP4KtPZwer/1oumxOLcR8BhEG5YxSVRJfIwj+2kMyGbYYr8B78KLX0+BwHOlzu5b5A/bWmIpH05Y0eF0pu/E9ZxhxgSAPnTJt00= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712831895; c=relaxed/simple; bh=y4EZ650pTJjsw70bzU66pUEW+9z7K89oD8V1WEN0fz0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=p3cmExoZI5+JiStPJSn4NRjmQyKcOe4rea/bJ02ZfssTpA99AgGtKKPDF+v8XKYWMVlDyPQOcxxaA9jhtTP4okEEZwQohPFW9XypV4OHZZWLkYR7R2cot1UKSyv88kR2KZ9zEWGpuYBWM/H0Qv+q8jY4NxZYrq05n5mlIXf0Iz0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=RPSB2iuW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="RPSB2iuW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F887C433C7; Thu, 11 Apr 2024 10:38:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712831895; bh=y4EZ650pTJjsw70bzU66pUEW+9z7K89oD8V1WEN0fz0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RPSB2iuWNIT6HQEk+GPOTe+zoROOjizPqJiyvS/Id8lUT7LK6llTw69vbovauY0ex KhQRYIwlh3ccoSzgzHgNtqnDlQxnyOycfH58vP9llxN9eJwE5V72kNBXnHXZc1OyyU hnY4j+VXUS46UGgZmHlAV3t3B3L761i6yS2QSJYw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Oliver Neukum Subject: [PATCH 5.10 162/294] usb: cdc-wdm: close race between read and workqueue Date: Thu, 11 Apr 2024 11:55:25 +0200 Message-ID: <20240411095440.520699753@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095435.633465671@linuxfoundation.org> References: <20240411095435.633465671@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oliver Neukum commit 339f83612f3a569b194680768b22bf113c26a29d upstream. wdm_read() cannot race with itself. However, in service_outstanding_interrupt() it can race with the workqueue, which can be triggered by error handling. Hence we need to make sure that the WDM_RESPONDING flag is not just only set but tested. Fixes: afba937e540c9 ("USB: CDC WDM driver") Cc: stable Signed-off-by: Oliver Neukum Link: https://lore.kernel.org/r/20240314115132.3907-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-wdm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -471,6 +471,7 @@ out_free_mem: static int service_outstanding_interrupt(struct wdm_device *desc) { int rv = 0; + int used; /* submit read urb only if the device is waiting for it */ if (!desc->resp_count || !--desc->resp_count) @@ -485,7 +486,10 @@ static int service_outstanding_interrupt goto out; } - set_bit(WDM_RESPONDING, &desc->flags); + used = test_and_set_bit(WDM_RESPONDING, &desc->flags); + if (used) + goto out; + spin_unlock_irq(&desc->iuspin); rv = usb_submit_urb(desc->response, GFP_KERNEL); spin_lock_irq(&desc->iuspin);