[PATCH 4.4 139/158] usb: wusbcore: fix unbalanced get/put cluster_id

Greg Kroah-Hartman
2019-08-02T09:35:37Z

From: Phong Tran <tranmanphong@gmail.com>

commit f90bf1ece48a736097ea224430578fe586a9544c upstream.

syzboot reported that
https://syzkaller.appspot.com/bug?extid=fd2bd7df88c606eea4ef

There is not consitency parameter in cluste_id_get/put calling.
In case of getting the id with result is failure, the wusbhc->cluster_id
will not be updated and this can not be used for wusb_cluster_id_put().

Tested report
https://groups.google.com/d/msg/syzkaller-bugs/0znZopp3-9k/oxOrhLkLEgAJ

Reproduce and gdb got the details:

139 addr = wusb_cluster_id_get();
(gdb) n
140 if (addr == 0)
(gdb) print addr
$1 = 254 '\376'
(gdb) n
142 result = __hwahc_set_cluster_id(hwahc, addr);
(gdb) print result
$2 = -71
(gdb) break wusb_cluster_id_put
Breakpoint 3 at 0xffffffff836e3f20: file drivers/usb/wusbcore/wusbhc.c, line 384.
(gdb) s
Thread 2 hit Breakpoint 3, wusb_cluster_id_put (id=0 '\000') at drivers/usb/wusbcore/wusbhc.c:384
384 id = 0xff - id;
(gdb) n
385 BUG_ON(id >= CLUSTER_IDS);
(gdb) print id
$3 = 255 '\377'

Reported-by: syzbot+fd2bd7df88c606eea4ef@syzkaller.appspotmail.com
Signed-off-by: Phong Tran <tranmanphong@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190724020601.15257-1-tranmanphong@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/host/hwa-hc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/host/hwa-hc.c
+++ b/drivers/usb/host/hwa-hc.c
@@ -173,7 +173,7 @@ out:
return result;

error_set_cluster_id:
- wusb_cluster_id_put(wusbhc->cluster_id);
+ wusb_cluster_id_put(addr);
error_cluster_id_get:
goto out;