[MPlayer-users] patch to fix bad code (UMR) in mp3lib/layer2.c causing signal 11 in mplayer
Nilmoni Deb
ndeb at ece.cmu.edu
Thu Jan 23 08:00:02 CET 2003
This is in reference to the bug reported in
http://mplayerhq.hu/pipermail/mplayer-users/2003-January/027281.html .
The bug appearred for a movie whose audio is mp2 (so thats all is needed
to reproduce the problem since the bug is in mp3lib/layer2.c).
The problem is very easy to see as follows:
In mp3lib/sr1.c, look at the line 226:
if(fr->sampling_frequency>8) return FALSE; // valid: 0..8
which allows fr->sampling_frequency to go up to 8.
Now, in mp3lib/layer2.c, in the function definition of II_select_table,
this code exists:
if(fr->lsf)
table = 4;
else
table = translate[fr->sampling_frequency][2-fr->stereo][fr->bitrate_index];
The problem is that in II_select_table function definition, translate is
declared as:
static int translate[3][2][16] = .....
which means fr->sampling_frequency must be < 3 to prevent illegal memory
reads.
Obviously, the code does not bother about what would happen if
fr->sampling_frequency lies in the range [3,8]. In my test case,
fr->sampling_frequency = 3 and naturally there is a problem.
Here is a patch to fix this:
----- PATCH STARTS NEXT LINE ---------------
--- layer2.c 2003-01-08 02:20:23.000000000 +0000
+++ layer2.c.new 2003-01-23 01:49:55.000000000 +0000
@@ -241,13 +241,28 @@
static void II_select_table(struct frame *fr)
{
- static int translate[3][2][16] =
- { { { 0,2,2,2,2,2,2,0,0,0,1,1,1,1,1,0 } ,
- { 0,2,2,0,0,0,1,1,1,1,1,1,1,1,1,0 } } ,
- { { 0,2,2,2,2,2,2,0,0,0,0,0,0,0,0,0 } ,
- { 0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0 } } ,
- { { 0,3,3,3,3,3,3,0,0,0,1,1,1,1,1,0 } ,
- { 0,3,3,0,0,0,1,1,1,1,1,1,1,1,1,0 } } };
+ static int translate[8][2][16] =
+ { { { 0,2,2,2,2,2,2,0,0,0,1,1,1,1,1,0 } , /*44.1 stereo*/
+ { 0,2,2,0,0,0,1,1,1,1,1,1,1,1,1,0 } } , /*44.1 mono*/
+ { { 0,2,2,2,2,2,2,0,0,0,0,0,0,0,0,0 } , /*48 stereo*/
+ { 0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0 } } , /*48 mono*/
+ { { 0,3,3,3,3,3,3,0,0,0,1,1,1,1,1,0 } , /*32 stereo*/
+ { 0,3,3,0,0,0,1,1,1,1,1,1,1,1,1,0 } } , /*32 mono*/
+ { { 2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,0 } , /*22.05 stereo*/
+ { 2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,0 } } , /*22.05 mono*/
+ { { 2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,0 } , /*24 stereo*/
+ { 2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,0 } } , /*24 mono*/
+ { { 2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,0 } , /*16 stereo*/
+ { 2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,0 } } , /*16 mono*/
+ { { 2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,0 } , /*11.025 stereo*/
+ { 2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,0 } } , /*11.025 mono*/
+ { { 2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,0 } , /*12 stereo*/
+ { 2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,0 } } , /*12 mono*/
+ { { 2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,0 } , /*8 stereo*/
+ { 2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,0 } } /*8 mono*/
+/* 0 48 64 96 128 192 256 384 */
+/* 32 56 80 112 160 224 320 XX*/
+ };
int table,sblim;
static struct al_table *tables[5] =
----- PATCH ENDED PREVIOUS LINE ---------------
This is from Nick.
thanks
- Nil
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