From cf697df5ad1495f167181dec0976ee228bec6378 Mon Sep 17 00:00:00 2001 From: Martin Storsjo Date: Fri, 20 Oct 2017 16:05:02 +0300 Subject: Avoid reading out of bounds due to negative aaIccIndexMapped Fixes: 3452/clusterfuzz-testcase-4898065225875456 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg --- libSBRdec/src/psdec.cpp | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/libSBRdec/src/psdec.cpp b/libSBRdec/src/psdec.cpp index 965917a..88a79a4 100644 --- a/libSBRdec/src/psdec.cpp +++ b/libSBRdec/src/psdec.cpp @@ -944,7 +944,7 @@ void initSlotBasedRotation( HANDLE_PS_DEC h_ps_d, /*!< pointer to the module sta FIXP_SGL invL; FIXP_DBL ScaleL, ScaleR; - FIXP_DBL Alpha, Beta; + FIXP_DBL Alpha, Beta, AlphasValue; FIXP_DBL h11r, h12r, h21r, h22r; const FIXP_DBL *PScaleFactors; @@ -1015,8 +1015,11 @@ void initSlotBasedRotation( HANDLE_PS_DEC h_ps_d, /*!< pointer to the module sta ScaleR = PScaleFactors[noIidSteps + h_ps_d->specificTo.mpeg.coef.aaIidIndexMapped[env][bin]]; ScaleL = PScaleFactors[noIidSteps - h_ps_d->specificTo.mpeg.coef.aaIidIndexMapped[env][bin]]; - Beta = fMult (fMult( Alphas[h_ps_d->specificTo.mpeg.coef.aaIccIndexMapped[env][bin]], ( ScaleR - ScaleL )), FIXP_SQRT05); - Alpha = Alphas[h_ps_d->specificTo.mpeg.coef.aaIccIndexMapped[env][bin]]>>1; + AlphasValue = 0; + if (h_ps_d->specificTo.mpeg.coef.aaIccIndexMapped[env][bin] >= 0) + AlphasValue = Alphas[h_ps_d->specificTo.mpeg.coef.aaIccIndexMapped[env][bin]]; + Beta = fMult (fMult( AlphasValue, ( ScaleR - ScaleL )), FIXP_SQRT05); + Alpha = AlphasValue>>1; /* Alpha and Beta are now both scaled by 2 shifts right */ -- cgit v1.2.3