[PATCH 4.4 22/22] binder: add missing binder_unlock()

From: Greg Kroah-Hartman
Date: Mon Feb 26 2018 - 15:19:33 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------


From: Eric Biggers <ebiggers@xxxxxxxxxx>

When commit 4be5a2810489 ("binder: check for binder_thread allocation
failure in binder_poll()") was applied to 4.4-stable and 4.9-stable it
was forgotten to release the global binder lock in the new error path.
The global binder lock wasn't removed until v4.14, by commit
a60b890f607d ("binder: remove global binder lock").

Fix the new error path to release the lock.

Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/android/binder.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2622,8 +2622,10 @@ static unsigned int binder_poll(struct f
binder_lock(__func__);

thread = binder_get_thread(proc);
- if (!thread)
+ if (!thread) {
+ binder_unlock(__func__);
return POLLERR;
+ }

wait_for_proc_work = thread->transaction_stack == NULL &&
list_empty(&thread->todo) && thread->return_error == BR_OK;