Fix heap buffer overflow in sbrDecoder_AssignQmfChannels2SbrChannels().
In the bug the SBR decoder has already set up 9 channels and tries to
allocate one more channel. The assignment of the QMF channels to SBR
channels fails since the QMF domain manages only 8+1 channels instead
of 10 channels as reqeusted by SBR.
Here we have added a check in sbrDecoder_InitElement() which will
return with a parse error in case additional SBR channels would exceed
the maximum number of SBR channels. This solves the potential heap
buffer overflow.
Bug: 158762825
Test: atest DecoderTestAacDrc DecoderTestAacFormat DecoderTestXheAac
Change-Id: I0150ac6d5a47ffce883010f531928656eebc619e
Merged-In: I0150ac6d5a47ffce883010f531928656eebc619e
(cherry picked from commit bb8f983bf36ee2ad8af6acebf4823a58060004ab)
diff --git a/libSBRdec/src/sbrdecoder.cpp b/libSBRdec/src/sbrdecoder.cpp
index 6e4aad4..55f929f 100644
--- a/libSBRdec/src/sbrdecoder.cpp
+++ b/libSBRdec/src/sbrdecoder.cpp
@@ -1,7 +1,7 @@
/* -----------------------------------------------------------------------------
Software License for The Fraunhofer FDK AAC Codec Library for Android
-© Copyright 1995 - 2019 Fraunhofer-Gesellschaft zur Förderung der angewandten
+© Copyright 1995 - 2020 Fraunhofer-Gesellschaft zur Förderung der angewandten
Forschung e.V. All rights reserved.
1. INTRODUCTION
@@ -617,10 +617,6 @@
self->numSbrChannels -= self->pSbrElement[elementIndex]->nChannels;
}
- /* Save element ID for sanity checks and to have a fallback for concealment.
- */
- self->pSbrElement[elementIndex]->elementID = elementID;
-
/* Determine amount of channels for this element */
switch (elementID) {
case ID_NONE:
@@ -653,12 +649,16 @@
}
/* Sanity check to avoid memory leaks */
- if (elChannels < self->pSbrElement[elementIndex]->nChannels) {
+ if (elChannels < self->pSbrElement[elementIndex]->nChannels ||
+ (self->numSbrChannels + elChannels) > (8) + (1)) {
self->numSbrChannels += self->pSbrElement[elementIndex]->nChannels;
sbrError = SBRDEC_PARSE_ERROR;
goto bail;
}
+ /* Save element ID for sanity checks and to have a fallback for concealment.
+ */
+ self->pSbrElement[elementIndex]->elementID = elementID;
self->pSbrElement[elementIndex]->nChannels = elChannels;
for (ch = 0; ch < elChannels; ch++) {
