Hi,
Please find the patch below as per previous discussion for Linux Kernel
version: linux-2.6.11.10. Hope there are no more issues.
--- linux-2.6.11.10/drivers/usb/serial/usb-serial.c.orig
2005-06-15 15:56:48.000000000 +0530
+++ linux-2.6.11.10/drivers/usb/serial/usb-serial.c 2005-06-16
11:36:31.136320864 +0530
@@ -546,11 +546,14 @@ static void serial_close(struct tty_stru
/* only call the device specific close if this
* port is being closed by the last owner */
port->serial->type->close(port, filp);
-
- if (port->tty) {
- if (port->tty->driver_data)
- port->tty->driver_data = NULL;
- port->tty = NULL;
+ /* An open call might be pending while close is
in progress.
+ * Must check port->open_count before freeing
tty */
+ if (port->open_count == 0) {
+ if (port->tty) {
+ if (port->tty->driver_data)
+ port->tty->driver_data =
NULL;
+ port->tty = NULL;
+ }
}
module_put(port->serial->type->owner);
Description of Patch
--------------------
This patch fixes a race condition in the serial_close method in the
usb-serial layer.
There can be a scenario where a usb-serial adapter device driver's
'open' method
is called while a close on the same port of the device is happening.
This would lead to inconsistent value of the port->open_count variable
and lead
to freeing of tty data structures even when the port is in use.
Developer's Certificate of Origin 1.0
By making a contribution to this project, I certify that:
(a) The contribution was created in whole or in part by me and I
have the right to submit it under the open source license
indicated in the file; or
(b) The contribution is based upon previous work that, to the
best
of my knowledge, is covered under an appropriate open source
license and I have the right under that license to submit
that
work with modifications, whether created in whole or in part
by me, under the same open source license (unless I am
permitted to submit under a different license), as indicated
in the file; or
(c) The contribution was provided directly to me by some other
person who certified (a), (b) or (c) and I have not modified
it.
Signed-off-by: Chinmay M. Kale <[EMAIL PROTECTED]>
-------------------------------------------------------
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