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 B950729CE7; Wed, 2 Oct 2024 13:47:40 +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=1727876860; cv=none; b=sCt1lRdGbFefT9e20JNOOQ7qZoEWPMGOGz6zwvCzB9TdC8XL7KIVnrtLV4rf6HNUrB+ENUOFi9yDNAF+wmUpX0Rrh8hpiHYkF1PCnocJgfoWkMM0VD19H+7lRV4mmh1wFN+0neg5VHHwAQUs1OVaZjwxlWz79dJK2jFNTb0QsL4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727876860; c=relaxed/simple; bh=ebXeZZvtodCVH7vZeMBQs8uJVVUYr7+VH/YUqUbmq3U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lWViT7TZRvzWt9AwFm161XXFTPS4bhBFaIeSqXA5dlgmP2EndcuQXfELvgTuYqaXURWZ38XcTTawZxKnCySy0iaSLQ5b1ho1szKIHH+q7KY6Lyd9JYxspGaTubGvFvou7S6arNI6/BpKfqH9UCYdyjmXoX6FhRMEE6TAWl5jvUw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=l+NznNB3; 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="l+NznNB3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E96E2C4CEC2; Wed, 2 Oct 2024 13:47:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1727876860; bh=ebXeZZvtodCVH7vZeMBQs8uJVVUYr7+VH/YUqUbmq3U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l+NznNB3M7mUsVF9Q+oYl7sVL4fGcFSKFn6mJ5X2riXsbTTxYIsZxxtKRB2QkMMQj MeuAb7DscWkLdiGW88CxSPZC3SHYeM9nmJdRxfBKwHYpud7Tq05uRJfPrY5KoCDGwZ ZbjPLJJcQgKLAPV+VITUEXUQ1Vvd68s2NQ5JsPmU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Oliver Neukum Subject: [PATCH 6.11 584/695] USB: misc: yurex: fix race between read and write Date: Wed, 2 Oct 2024 14:59:42 +0200 Message-ID: <20241002125845.824442928@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241002125822.467776898@linuxfoundation.org> References: <20241002125822.467776898@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oliver Neukum commit 93907620b308609c72ba4b95b09a6aa2658bb553 upstream. The write code path touches the bbu member in a non atomic manner without taking the spinlock. Fix it. The bug is as old as the driver. Signed-off-by: Oliver Neukum CC: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240912132126.1034743-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/yurex.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/usb/misc/yurex.c +++ b/drivers/usb/misc/yurex.c @@ -404,7 +404,6 @@ static ssize_t yurex_read(struct file *f struct usb_yurex *dev; int len = 0; char in_buffer[MAX_S64_STRLEN]; - unsigned long flags; dev = file->private_data; @@ -419,9 +418,9 @@ static ssize_t yurex_read(struct file *f return -EIO; } - spin_lock_irqsave(&dev->lock, flags); + spin_lock_irq(&dev->lock); scnprintf(in_buffer, MAX_S64_STRLEN, "%lld\n", dev->bbu); - spin_unlock_irqrestore(&dev->lock, flags); + spin_unlock_irq(&dev->lock); mutex_unlock(&dev->io_mutex); return simple_read_from_buffer(buffer, count, ppos, in_buffer, len); @@ -511,8 +510,11 @@ static ssize_t yurex_write(struct file * __func__, retval); goto error; } - if (set && timeout) + if (set && timeout) { + spin_lock_irq(&dev->lock); dev->bbu = c2; + spin_unlock_irq(&dev->lock); + } return timeout ? count : -EIO; error: