Bjørn Mork f563926fed usb: cdc-wdm: resp_count can be 0 even if WDM_READ is set ...

Do not decrement resp_count if it's already 0.

We set resp_count to 0 when the device is closed.  The next open and
read will try to clear the WDM_READ flag if there was leftover data
in the read buffer. This fix is necessary to prevent resubmitting
the read URB in a tight loop because resp_count becomes negative.

The bug can easily be triggered from userspace by not reading all
data in the read buffer, and then closing and reopening the chardev.

Fixes: 8dd5cd5395 ("usb: cdc-wdm: avoid hanging on zero length reads")
Cc: <[email protected]> # 3.13
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

2014-01-12 20:13:28 -08:00

..

cdc-acm.c

Merge branch 3.13-rc4 into usb-next

2013-12-16 08:46:03 -08:00

cdc-acm.h

cdc-acm: add TIOCMIWAIT

2013-12-03 10:23:46 -08:00

cdc-wdm.c

usb: cdc-wdm: resp_count can be 0 even if WDM_READ is set

2014-01-12 20:13:28 -08:00

Kconfig

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Makefile

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usblp.c

usb: delete non-required instances of include <linux/init.h>

2014-01-08 15:01:39 -08:00

usbtmc.c

usb: delete non-required instances of include <linux/init.h>

2014-01-08 15:01:39 -08:00