Re: [PATCH] Memory leak in visor.c and ftdi_sio.c

From: Ian Abbott
Date: Fri Jun 04 2004 - 11:42:58 EST


On 04/06/2004 15:59, nardelli wrote:
Note that I have not verified any of the below on
hardware associated with drivers/usb/serial/ftdi_sio.c,
only with drivers/usb/serial/visor.c. If anyone has
hardware for this device, I would appreciate your comments.

A memory leak occurs in both drivers/usb/serial/ftdi_sio.c
and drivers/usb/serial/visor.c when the usb device is
unplugged while data is being written to the device. This
patch should clear that up.

The change to ftdi_sio.c looks correct to me.

I made the original change to ftdi_sio.c to allocate the write urbs and their transfer buffers dynamically (instead of using a preallocated pool) and I copied that technique from visor.c!

A related problem with the current implementation is that is easy to run out of memory by running something similar to this:

# cat /dev/zero > /dev/ttyUSB0

That affects both the ftdi_sio and visor drivers.

--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=-
-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-

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