Fix out of bound memory access in lppTransposer
In TRANSPOSER_SETTINGS, initialize the whole bwBorders array to a
reasonable value to guarantee correct termination in while loop
in lppTransposer function. This fixes the reported bug.
For completeness:
- clear the whole bwIndex array instead of noOfPatches entries only.
- abort criterion in while loop to prevent potential
infinite loop, and limit bwIndex[patch] to a valid range.
Test: see bug for malicious content, decoded with "stagefright -s -a"
Bug: 65280786
Change-Id: I16ed2e1c0f1601926239a652ca20a91284151843
(cherry picked from commit 6d3dd40e204bf550abcfa589bd9615df8778e118)
diff --git a/libSBRdec/src/lpp_tran.cpp b/libSBRdec/src/lpp_tran.cpp
index 117e739..343aec3 100644
--- a/libSBRdec/src/lpp_tran.cpp
+++ b/libSBRdec/src/lpp_tran.cpp
@@ -293,7 +293,7 @@
}
/* init bwIndex for each patch */
- FDKmemclear(bwIndex, pSettings->noOfPatches*sizeof(INT));
+ FDKmemclear(bwIndex, MAX_NUM_PATCHES*sizeof(INT));
/*
Calc common low band scale factor
@@ -621,9 +621,9 @@
FDK_ASSERT( hiBand < (64) );
/* bwIndex[patch] is already initialized with value from previous band inside this patch */
- while (hiBand >= pSettings->bwBorders[bwIndex[patch]])
+ while (hiBand >= pSettings->bwBorders[bwIndex[patch]] && bwIndex[patch] < MAX_NUM_PATCHES-1) {
bwIndex[patch]++;
-
+ }
/*
Filter Step 2: add the left slope with the current filter to the buffer
@@ -962,6 +962,10 @@
for(i = 0 ; i < noNoiseBands; i++){
pSettings->bwBorders[i] = noiseBandTable[i+1];
}
+ for (;i < MAX_NUM_NOISE_VALUES; i++) {
+ pSettings->bwBorders[i] = 255;
+ }
+
/*
* Choose whitening factors