[FFmpeg-cvslog] avcodec/aacsbr_fixed: Fix multiple runtime error: shift exponent 170 is too large for 32-bit type 'int'

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Sun May 21 00:06:10 2017 +0200| [88fabd801693545b4d1de360fbad373d61374574] | committer: Michael Niedermayer

avcodec/aacsbr_fixed: Fix multiple runtime error: shift exponent 170 is too large for 32-bit type 'int'

Fixes part of 1709/clusterfuzz-testcase-minimized-4513580554649600

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 6310fc714de3cd73848416ead73228fcef8b6dc0)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=88fabd801693545b4d1de360fbad373d61374574
---

 libavcodec/aacsbr_fixed.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/libavcodec/aacsbr_fixed.c b/libavcodec/aacsbr_fixed.c
index a56305746b..2410c25d80 100644
--- a/libavcodec/aacsbr_fixed.c
+++ b/libavcodec/aacsbr_fixed.c
@@ -578,20 +578,25 @@ 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) {
-                  shift = 22 - in[m  ].exp;
-                  round = 1 << (shift-1);
-                  out[2*m  ] += (in[m  ].mant * A + round) >> shift;
+                    shift = 22 - in[m  ].exp;
+                    if (shift < 32) {
+                        round = 1 << (shift-1);
+                        out[2*m  ] += (in[m  ].mant * A + round) >> shift;
+                    }
 
-                  shift = 22 - in[m+1].exp;
-                  round = 1 << (shift-1);
-                  out[2*m+2] += (in[m+1].mant * B + 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(m_max&1)
                 {
-                  shift = 22 - in[m  ].exp;
-                  round = 1 << (shift-1);
-
-                  out[2*m  ] += (in[m  ].mant * A + round) >> shift;
+                    shift = 22 - in[m  ].exp;
+                    if (shift < 32) {
+                        round = 1 << (shift-1);
+                        out[2*m  ] += (in[m  ].mant * A + round) >> shift;
+                    }
                 }
             }
             indexnoise = (indexnoise + m_max) & 0x1ff;