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authorBaolin Wang <baolin.wang@linaro.org>2016-06-30 12:10:23 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-03 07:23:18 +0300
commita12cf3214235681a347a53c93378479caab3f404 (patch)
tree9afec8dc476282de57e7ccb390d8a7f6c4ff40a5
parent36be44e1905d593402d373aa35b48ceec9ae46f0 (diff)
downloadlinux-a12cf3214235681a347a53c93378479caab3f404.tar.xz
usb: gadget: Add the gserial port checking in gs_start_tx()
commit 511a36d2f357724312bb3776d2f6eed3890928b2 upstream. When usb gadget is set gadget serial function, it will be crash in below situation. It will clean the 'port->port_usb' pointer in gserial_disconnect() function when usb link is inactive, but it will release lock for disabling the endpoints in this function. Druing the lock release period, it maybe complete one request to issue gs_write_complete()--->gs_start_tx() function, but the 'port->port_usb' pointer had been set NULL, thus it will be crash in gs_start_tx() function. This patch adds the 'port->port_usb' pointer checking in gs_start_tx() function to avoid this situation. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/gadget/function/u_serial.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index 4ea44f7122ee..d73618475664 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -361,10 +361,15 @@ __acquires(&port->port_lock)
*/
{
struct list_head *pool = &port->write_pool;
- struct usb_ep *in = port->port_usb->in;
+ struct usb_ep *in;
int status = 0;
bool do_tty_wake = false;
+ if (!port->port_usb)
+ return status;
+
+ in = port->port_usb->in;
+
while (!port->write_busy && !list_empty(pool)) {
struct usb_request *req;
int len;