commit 11f10e295e6cdce6ac94da428d747673bdca6a59
author Andy Hung <hunga@google.com> Fri Oct 19 17:47:12 2018 -0700
committer Andy Hung <hunga@google.com> Fri Oct 19 17:51:58 2018 -0700
tree eafa40311f1c4e821e02a4efc566cd3e4aa615e5
parent a292c0ade6ed9e0df36df688113e63b277fd6ba6

audio_hw: make mixer_path obey limits of MIXER_PATH_MAX_LENGTH

Test: compile and sanity
Bug: 117999014
Change-Id: Ic4be8725765b83a2d5bc00414d663e3884be4ab2

hal/audio_hw.c

diff --git a/hal/audio_hw.c b/hal/audio_hw.c
index 261531d..3425eb9 100644
--- a/hal/audio_hw.c
+++ b/hal/audio_hw.c
@@ -601,7 +601,7 @@
                        struct audio_usecase *usecase)
 {
     snd_device_t snd_device;
-    char mixer_path[50];
+    char mixer_path[MIXER_PATH_MAX_LENGTH];
 
     if (usecase == NULL)
         return -EINVAL;
@@ -614,8 +614,13 @@
         snd_device = usecase->out_snd_device;
     audio_extn_utils_send_app_type_cfg(adev, usecase);
     audio_extn_utils_send_audio_calibration(adev, usecase);
-    strcpy(mixer_path, use_case_table[usecase->id]);
+
+    // we shouldn't truncate mixer_path
+    ALOGW_IF(strlcpy(mixer_path, use_case_table[usecase->id], sizeof(mixer_path))
+            >= sizeof(mixer_path), "%s: truncation on mixer path", __func__);
+    // this also appends to mixer_path
     platform_add_backend_name(adev->platform, mixer_path, snd_device);
+
     audio_extn_sound_trigger_update_stream_status(usecase, ST_EVENT_STREAM_BUSY);
     ALOGD("%s: usecase(%d) apply and update mixer path: %s", __func__,  usecase->id, mixer_path);
     audio_route_apply_and_update_path(adev->audio_route, mixer_path);
@@ -628,7 +633,7 @@
                         struct audio_usecase *usecase)
 {
     snd_device_t snd_device;
-    char mixer_path[50];
+    char mixer_path[MIXER_PATH_MAX_LENGTH];
 
     if (usecase == NULL)
         return -EINVAL;
@@ -638,9 +643,14 @@
         snd_device = usecase->in_snd_device;
     else
         snd_device = usecase->out_snd_device;
-    strcpy(mixer_path, use_case_table[usecase->id]);
+
+    // we shouldn't truncate mixer_path
+    ALOGW_IF(strlcpy(mixer_path, use_case_table[usecase->id], sizeof(mixer_path))
+            >= sizeof(mixer_path), "%s: truncation on mixer path", __func__);
+    // this also appends to mixer_path
     platform_add_backend_name(adev->platform, mixer_path, snd_device);
     ALOGD("%s: usecase(%d) reset and update mixer path: %s", __func__, usecase->id, mixer_path);
+
     audio_route_reset_and_update_path(adev->audio_route, mixer_path);
     audio_extn_sound_trigger_update_stream_status(usecase, ST_EVENT_STREAM_FREE);