commit dbb6ba612745097ffc317fff327a5408ea17bbc5
author dvdli <dvdli@google.com> Thu Oct 29 16:32:44 2020 +0800
committer dvdli <dvdli@google.com> Thu Oct 29 16:32:44 2020 +0800
tree 346a04acc846f75e590b3404ec3babf83fbd4c0c
parent b39234c6a35378abb18e81ea0967331f68fd9029

AOSP CL "tinyalsa: check for NULL mmap_status"

https://android.googlesource.com/platform/external/tinyalsa/+/62644f7a3c4cfa18d7935f731cf59b675669d17a

commit	62644f7a3c4cfa18d7935f731cf59b675669d17a
author	Phil Burk <philburk@google.com>

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

src/pcm.c

diff --git a/src/pcm.c b/src/pcm.c
index a175668..b592780 100644
--- a/src/pcm.c
+++ b/src/pcm.c
@@ -1575,6 +1575,9 @@
     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);