diff options
| author |   Johan Hovold <johan@kernel.org> | 2019-10-09 12:48:44 +0200 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-10 12:45:06 +0200 |
| commit | 7c5b971d623fdb40c03205e99f9ef68002b34726 (patch) | |
| tree | cf70ffb402c783466d0a1dfb96409e8e887bca77 /drivers/usb | |
| parent | USB: iowarrior: fix use-after-free after driver unbind (diff) | |
| download | linux-dev-7c5b971d623fdb40c03205e99f9ef68002b34726.tar.xz linux-dev-7c5b971d623fdb40c03205e99f9ef68002b34726.zip | |
USB: iowarrior: drop redundant disconnect mutex
Drop the redundant disconnect mutex which was introduced after the
open-disconnect race had been addressed generally in USB core by commit
d4ead16f50f9 ("USB: prevent char device open/deregister race").
Specifically, the rw-semaphore in core guarantees that all calls to
open() will have completed and that no new calls to open() will occur
after usb_deregister_dev() returns. Hence there is no need use the
driver data as an inverted disconnected flag.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191009104846.5925-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/misc/iowarrior.c | 17 |
1 files changed, 2 insertions, 15 deletions
diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c index f405fa734bcc..d844c2098e42 100644 --- a/drivers/usb/misc/iowarrior.c +++ b/drivers/usb/misc/iowarrior.c @@ -58,7 +58,6 @@ MODULE_LICENSE("GPL"); static DEFINE_MUTEX(iowarrior_mutex); static struct usb_driver iowarrior_driver; -static DEFINE_MUTEX(iowarrior_open_disc_lock); /*--------------*/ /* data */ @@ -601,16 +600,13 @@ static int iowarrior_open(struct inode *inode, struct file *file) return -ENODEV; } - mutex_lock(&iowarrior_open_disc_lock); dev = usb_get_intfdata(interface); if (!dev) { - mutex_unlock(&iowarrior_open_disc_lock); mutex_unlock(&iowarrior_mutex); return -ENODEV; } mutex_lock(&dev->mutex); - mutex_unlock(&iowarrior_open_disc_lock); /* Only one process can open each device, no sharing. */ if (dev->opened) { @@ -842,7 +838,6 @@ static int iowarrior_probe(struct usb_interface *interface, if (retval) { /* something prevented us from registering this driver */ dev_err(&interface->dev, "Not able to get a minor for this device.\n"); - usb_set_intfdata(interface, NULL); goto error; } @@ -866,16 +861,8 @@ error: */ static void iowarrior_disconnect(struct usb_interface *interface) { - struct iowarrior *dev; - int minor; - - dev = usb_get_intfdata(interface); - mutex_lock(&iowarrior_open_disc_lock); - usb_set_intfdata(interface, NULL); - - minor = dev->minor; - mutex_unlock(&iowarrior_open_disc_lock); - /* give back our minor - this will call close() locks need to be dropped at this point*/ + struct iowarrior *dev = usb_get_intfdata(interface); + int minor = dev->minor; usb_deregister_dev(interface, &iowarrior_class); |