From fd0da0eef0076732a65d173186081c125e28068f Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 13 Jun 2017 16:25:59 +0200 Subject: [PATCH] avcodec/aacsbr_fixed: Check shift in sbr_hf_assemble() Fixes: runtime error: shift exponent -10 is negative Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit d1992448d37f7cfa2acda5cc729dc0ff1b019390) Signed-off-by: Michael Niedermayer --- libavcodec/aacsbr_fixed.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/libavcodec/aacsbr_fixed.c b/libavcodec/aacsbr_fixed.c index 2410c25d80..a12ecd19c9 100644 --- a/libavcodec/aacsbr_fixed.c +++ b/libavcodec/aacsbr_fixed.c @@ -578,22 +578,30 @@ static void sbr_hf_assemble(int Y1[38][64][2], SoftFloat *in = sbr->s_m[e]; for (m = 0; m+1 < m_max; m+=2) { + int shift2; shift = 22 - in[m ].exp; + shift2= 22 - in[m+1].exp; + if (shift < 1 || shift2 < 1) { + av_log(NULL, AV_LOG_ERROR, "Overflow in sbr_hf_assemble, shift=%d,%d\n", shift, shift2); + return; + } if (shift < 32) { round = 1 << (shift-1); out[2*m ] += (in[m ].mant * A + round) >> shift; } - shift = 22 - in[m+1].exp; - if (shift < 32) { - round = 1 << (shift-1); - out[2*m+2] += (in[m+1].mant * B + round) >> shift; + if (shift2 < 32) { + round = 1 << (shift2-1); + out[2*m+2] += (in[m+1].mant * B + round) >> shift2; } } if(m_max&1) { shift = 22 - in[m ].exp; - if (shift < 32) { + if (shift < 1) { + av_log(NULL, AV_LOG_ERROR, "Overflow in sbr_hf_assemble, shift=%d\n", shift); + return; + } else if (shift < 32) { round = 1 << (shift-1); out[2*m ] += (in[m ].mant * A + round) >> shift; }