3.16.57-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Eric Biggers <ebiggers@xxxxxxxxxx>
commit f88982679f54f75daa5b8eff3da72508f1e7422f upstream.
If the kzalloc() in binder_get_thread() fails, binder_poll()
dereferences the resulting NULL pointer.
Fix it by returning POLLERR if the memory allocation failed.
This bug was found by syzkaller using fault injection.
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Fixes: 457b9a6f09f0 ("Staging: android: add binder driver")
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.16:
- Drop the binder global lock before returning
- Adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -2572,6 +2572,10 @@ static unsigned int binder_poll(struct f
binder_lock(__func__);
thread = binder_get_thread(proc);
+ if (!thread) {
+ binder_unlock(__func__);
+ return POLLERR;
+ }
wait_for_proc_work = thread->transaction_stack == NULL &&
list_empty(&thread->todo) && thread->return_error == BR_OK;
