USB: resizing usbmon binary interface buffer causes protection faults

commit 33d973ad88ceb83ed1449592b7574b5b5bb33ac6 upstream.

Enlarging the buffer size via the MON_IOCT_RING_SIZE ioctl causes
general protection faults. It appears the culprit is an incorrect
argument to mon_free_buff: instead of passing the size of the current
buffer being freed, the size of the new buffer is passed.

Use the correct size argument to mon_free_buff when changing the size of
the buffer.

Signed-off-by: Steven Robertson <steven@strobe.cc>
Acked-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c
index 61c76b13f0f18eed38902054d36943d7ce472dfc..56c93cac24c135a0dbe0692a5c02764522e0981e 100644 (file)
--- a/drivers/usb/mon/mon_bin.c
+++ b/drivers/usb/mon/mon_bin.c
@@ -1009,7 +1009,7 @@ static int mon_bin_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
                mutex_lock(&rp->fetch_lock);
                spin_lock_irqsave(&rp->b_lock, flags);
-               mon_free_buff(rp->b_vec, size/CHUNK_SIZE);
+               mon_free_buff(rp->b_vec, rp->b_size/CHUNK_SIZE);
                kfree(rp->b_vec);
                rp->b_vec  = vec;
                rp->b_size = size;