From: Valentin Vidic <vvidic@valentin-vidic.from.hr>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oliver Neukum <oneukum@suse.com>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
Valentin Vidic <vvidic@valentin-vidic.from.hr>,
syzbot+0761012cebf7bdb38137@syzkaller.appspotmail.com
Subject: [PATCH] usb: iowarrior: fix access to freed data structure
Date: Wed, 9 Oct 2019 00:23:07 +0200 [thread overview]
Message-ID: <20191008222307.18587-1-vvidic@valentin-vidic.from.hr> (raw)
struct iowarrior gets freed prematurely in iowarrior_release while
it is still being referenced from usb_interface, so let only
iowarrior_disconnect call iowarrior_delete.
Fixes: KMSAN: uninit-value in iowarrior_disconnect
Reported-by: syzbot+0761012cebf7bdb38137@syzkaller.appspotmail.com
Signed-off-by: Valentin Vidic <vvidic@valentin-vidic.from.hr>
---
drivers/usb/misc/iowarrior.c | 35 +++++++++++++++--------------------
1 file changed, 15 insertions(+), 20 deletions(-)
diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index f5bed9f29e56..0492ea76c4bf 100644
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -638,7 +638,6 @@ static int iowarrior_open(struct inode *inode, struct file *file)
static int iowarrior_release(struct inode *inode, struct file *file)
{
struct iowarrior *dev;
- int retval = 0;
dev = file->private_data;
if (!dev)
@@ -650,27 +649,23 @@ static int iowarrior_release(struct inode *inode, struct file *file)
mutex_lock(&dev->mutex);
if (dev->opened <= 0) {
- retval = -ENODEV; /* close called more than once */
mutex_unlock(&dev->mutex);
- } else {
- dev->opened = 0; /* we're closing now */
- retval = 0;
- if (dev->present) {
- /*
- The device is still connected so we only shutdown
- pending read-/write-ops.
- */
- usb_kill_urb(dev->int_in_urb);
- wake_up_interruptible(&dev->read_wait);
- wake_up_interruptible(&dev->write_wait);
- mutex_unlock(&dev->mutex);
- } else {
- /* The device was unplugged, cleanup resources */
- mutex_unlock(&dev->mutex);
- iowarrior_delete(dev);
- }
+ return -ENODEV; /* close called more than once */
}
- return retval;
+
+ dev->opened = 0; /* we're closing now */
+ if (dev->present) {
+ /*
+ * The device is still connected so we only shutdown
+ * pending read/write ops.
+ */
+ usb_kill_urb(dev->int_in_urb);
+ wake_up_interruptible(&dev->read_wait);
+ wake_up_interruptible(&dev->write_wait);
+ }
+
+ mutex_unlock(&dev->mutex);
+ return 0;
}
static __poll_t iowarrior_poll(struct file *file, poll_table * wait)
--
2.20.1
next reply other threads:[~2019-10-08 22:32 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-08 22:23 Valentin Vidic [this message]
2019-10-09 7:36 ` [PATCH] usb: iowarrior: fix access to freed data structure Johan Hovold
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