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 B16041D416E; Wed, 6 Nov 2024 12:12:46 +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=1730895166; cv=none; b=GONCTwUnvlcBfQANyNTKfiilGT3VCuZgaZsSJP3hFlVdTNdrhImFpJnRlzbD34MPfOthPCg0mE0Sf8KfWAOspjp+Yi0BmlVu+2wGNQAwX04XDEcHgh9yzZfC9DW7H6kF1mH3rStFmULZLaO59FXr/Lzf9ON6dNtM0nd4rWpQ5zY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730895166; c=relaxed/simple; bh=5j0ehDtPUj9sM5nnKmdqnojeWAMl9cpRHtg5KuM9lBc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lgZ0smKHfj+A7fXa1VsbRt7sLlJkaLC94cc1Rclibt2PgnzPTWIaIHES88ZEncGZE9Zm6OsaCAQ/+6no1MXaOGVbfq7jVnv5rQ5/34yYi0lIwNBzq+O2s5OSivscRQq/ehHt7cPxzLjQMuOw8HdOMtNhxD5G+Tdk/nj/dAowWl8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=k3GfvZ7Z; 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="k3GfvZ7Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 285FEC4CECD; Wed, 6 Nov 2024 12:12:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730895166; bh=5j0ehDtPUj9sM5nnKmdqnojeWAMl9cpRHtg5KuM9lBc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k3GfvZ7ZEI5FxkG/CMLmz7xJE32K1tG34yhBWDZogumMN0BSkwRyxYrOxbV2CQE6H wpdd89SEC8mPYEt0O4vM7pj2Fz6LssYAps6RSNkhrCMPizdl6eFIznOwbHtqRW4JEd efzwkPEdXUYzgFoYqDEo/p2HMcQ4350FrsgazUm4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Oliver Neukum , Sasha Levin Subject: [PATCH 4.19 126/350] USB: misc: yurex: fix race between read and write Date: Wed, 6 Nov 2024 13:00:54 +0100 Message-ID: <20241106120324.019632511@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241106120320.865793091@linuxfoundation.org> References: <20241106120320.865793091@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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oliver Neukum [ Upstream commit 93907620b308609c72ba4b95b09a6aa2658bb553 ] 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 Signed-off-by: Sasha Levin --- drivers/usb/misc/yurex.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c index a85cc0f3e15c4..5f271d25b633d 100644 --- a/drivers/usb/misc/yurex.c +++ b/drivers/usb/misc/yurex.c @@ -405,7 +405,6 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count, struct usb_yurex *dev; int len = 0; char in_buffer[MAX_S64_STRLEN]; - unsigned long flags; dev = file->private_data; @@ -418,9 +417,9 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count, if (WARN_ON_ONCE(dev->bbu > S64_MAX || dev->bbu < S64_MIN)) 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); @@ -510,8 +509,11 @@ static ssize_t yurex_write(struct file *file, const char __user *user_buffer, __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: -- 2.43.0