4.15-stable 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")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/android/binder.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -4346,6 +4346,8 @@ static unsigned int binder_poll(struct f
bool wait_for_proc_work;
thread = binder_get_thread(proc);
+ if (!thread)
+ return POLLERR;
binder_inner_proc_lock(thread->proc);
thread->looper |= BINDER_LOOPER_STATE_POLL;