#323 devided by zero issue

[niugx]

There is a devided by zero issue in line 182 of flanger.c file

182 double delay = f->lfo[(f->lfo_pos + channel_phase) % f->lfo_length];

with crafted mp3 file, f->lfo_length can be set to 0.

/////////issue information////////
/example0 hello.mp3 hello.aiff
Floating point exception (core dumped)

////////gdb debug infomation//////////
(gdb) r
Starting program:/sox-14.4.2/src/.libs/example0 hello.mp3 hello.aiff
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGFPE, Arithmetic exception.
0x00007ffff7b491b8 in flow (effp=0x605220, ibuf=0x60d410, obuf=0x615420, isamp=0x7fffffffe2f0, osamp=0x7fffffffe2f8) at flanger.c:182
182 double delay = f->lfo[(f->lfo_pos + channel_phase) % f->lfo_length];
(gdb) p f->lfo_length
$1 = 0
(gdb) bt
0x00007ffff7b491b8 in flow (effp=0x605220, ibuf=0x60d410, obuf=0x615420, isamp=0x7fffffffe2f0, osamp=0x7fffffffe2f8) at flanger.c:182
0x00007ffff7b38ba6 in flow_effect (chain=0x603b10, n=2) at effects.c:257
0x00007ffff7b39985 in sox_flow_effects (chain=0x603b10, callback=0x0, client_data=0x0) at effects.c:449
0x0000000000400e8a in main (argc=3, argv=0x7fffffffe5c8) at example0.c:89

Guoxiang Niu, Xiaolong Zhao, EaglEye Team

[Martin Guy]

https://codeberg.org/sox_ng/sox_ng/issues/536

[Martin Guy]

Do you still have a "crafted mp3 file" that provokes this? Thanks -M