commit 62644f7a3c4cfa18d7935f731cf59b675669d17a
author Phil Burk <philburk@google.com> Mon Aug 07 16:50:09 2017 -0700
committer Phil Burk <philburk@google.com> Mon Aug 07 16:50:09 2017 -0700
tree dff1f0c0da12c482bd5407cd5eedf497d50a1271
parent a2899bd8558dfd843da22cd0b03905d9d45343bd

tinyalsa: check for NULL mmap_status

pcm_mmap_get_hw_ptr() was not checking pcm->mmap_status and
crashed when it was NULL.

Bug: 64346189
Test: input_monitor.cpp, see bug report for repro steps
Change-Id: I8436686a231eb01a82dd28ca2cce561d5460bcd6

pcm.c

diff --git a/pcm.c b/pcm.c
index 614a14e..120d182 100644
--- a/pcm.c
+++ b/pcm.c
@@ -500,6 +500,9 @@
     if (rc < 0)
         return oops(pcm, errno, "pcm_sync_ptr failed");
 
+    if (pcm->mmap_status == NULL)
+        return oops(pcm, EINVAL, "pcm %p, mmap_status is NULL", pcm);
+
     if ((pcm->mmap_status->state != PCM_STATE_RUNNING) &&
             (pcm->mmap_status->state != PCM_STATE_DRAINING))
         return oops(pcm, ENOSYS, "invalid stream state %d", pcm->mmap_status->state);