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 960BE2F44; Wed, 2 Oct 2024 14:48:38 +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=1727880518; cv=none; b=L2+b14TJIPlQetDsBjNhr7gaoh1dU/DenIhUgHs61f6v7z8wsoJyrpslHxbzSERgkesx1Rbb6tciN9bQbywC1IzvaO5ZFiTe1i1W1BTSFH9XaCSE0/VizQfhqcUjXvjRsX+eckW80kzXxG2TZJgfDqr1U571qd4Fjq4EPtHaA7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727880518; c=relaxed/simple; bh=BABd0vStzH3wkQXX5Q9v3tAD04WjjCefaz4HkwzG9Ck=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QFHeY8VXHJne1tHPTHawRTBhwD7dPYZJy81a2wgbprmWSvaZG993K/NQXrz427lZ2wkDaa/oSJIZUJEcW9Lds1qBrRcsQPUncrRBulX0nuajZz+wFnOyfq1FiFa93LN+8zvt+648AWoUYU9iqLujLbuppgo0IasATwWxmU+a69k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=oomI6qSz; 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="oomI6qSz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B734C4CEC2; Wed, 2 Oct 2024 14:48:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1727880518; bh=BABd0vStzH3wkQXX5Q9v3tAD04WjjCefaz4HkwzG9Ck=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oomI6qSzQbTli3lwVRP+dCy9JpAJuMykJA/Jh/roOqIokcGl7peiwukIx300st1uC VZ7uPC8J7p+29kygk9BKXq7THF0xEbor3rZERaDX9yLrniLaH3gzaEhCHIN1i2CXvm pqdxeIsxD93ssQ4DkAA8k6WdgnSAEsr2W3DFiug0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Oliver Neukum , Sasha Levin Subject: [PATCH 6.6 486/538] USB: misc: yurex: fix race between read and write Date: Wed, 2 Oct 2024 15:02:05 +0200 Message-ID: <20241002125811.625631976@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241002125751.964700919@linuxfoundation.org> References: <20241002125751.964700919@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 6.6-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 5a13cddace0e6..44136989f6c6a 100644 --- a/drivers/usb/misc/yurex.c +++ b/drivers/usb/misc/yurex.c @@ -404,7 +404,6 @@ 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; @@ -417,9 +416,9 @@ 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); @@ -509,8 +508,11 @@ 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