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[Octave-bug-tracker] [bug #48078] Crash when using signal's remez functi
From: |
anonymous |
Subject: |
[Octave-bug-tracker] [bug #48078] Crash when using signal's remez function for close frequency band values + differentiator |
Date: |
Wed, 1 Jun 2016 15:17:06 +0000 (UTC) |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:46.0) Gecko/20100101 Firefox/46.0 |
URL:
<http://savannah.gnu.org/bugs/?48078>
Summary: Crash when using signal's remez function for close
frequency band values + differentiator
Project: GNU Octave
Submitted by: None
Submitted on: Wed 01 Jun 2016 03:17:04 PM UTC
Category: Octave Forge Package
Severity: 3 - Normal
Priority: 5 - Normal
Item Group: Crash
Status: None
Assigned to: None
Originator Name:
Originator Email:
Open/Closed: Open
Discussion Lock: Any
Release: 4.0.2
Operating System: GNU/Linux
_______________________________________________________
Details:
Hi,
I've found that, when using remez function from the forge package « signal
», if you give frequencies at the band edges too close from each other (as in
testcase.m), octave segfaults.
I've located the problem in remez.cc, l612-624:
for (i=0; i<numband; i++)
{
gridsize += (int)(2*r*griddensity*(bands[2*i+1] - bands[2*i]) + .5);
}
if (symmetry == NEGATIVE)
{
gridsize--;
}
Grid = (double *)malloc(gridsize * sizeof(double));
If 2*r*griddensity*(bands[2*i+1] - bands[2*i] <= 0.4, and the symmetry is
NEGATIVE (like in a differentiator), then gridsize = -1, and Grid points to
NULL, so octave crashes as soon as something tries to access it (like in
CreateDenseGrid).
I believe there should be a size check somewhere, but as I don't really now
how does remez work, I don't want to suggest something wrong.
Thanks!
_______________________________________________________
File Attachments:
-------------------------------------------------------
Date: Wed 01 Jun 2016 03:17:04 PM UTC Name: testcase.m Size: 269B By: None
<http://savannah.gnu.org/bugs/download.php?file_id=37331>
-------------------------------------------------------
Date: Wed 01 Jun 2016 03:17:04 PM UTC Name: gdbdump Size: 7kB By: None
<http://savannah.gnu.org/bugs/download.php?file_id=37332>
_______________________________________________________
Reply to this item at:
<http://savannah.gnu.org/bugs/?48078>
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- [Octave-bug-tracker] [bug #48078] Crash when using signal's remez function for close frequency band values + differentiator,
anonymous <=