bugGNU Octave - Bugs: bug #48078, [octave forge] (signal) crash in...

 
 

bug #48078: [octave forge] (signal) crash in remez with close frequency band values + differentiator

Submitted by:  None
Submitted on:  Wed 01 Jun 2016 03:17:04 PM UTC  
 
Category: Octave Forge PackageSeverity: 3 - Normal
Priority: 5 - NormalItem Group: Segfault, Bus Error, etc.
Status: ConfirmedAssigned to: None
Originator Name: Originator Email: -unavailable-
Open/Closed: OpenRelease: 4.0.2
Operating System: GNU/Linux

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Thu 02 Jun 2016 03:40:21 AM UTC, comment #1:

The current remez implementation has several bugs, including poor filter design, and apparently this crash. Please try patch #8535 for a remez replacement, it has been reported to work with your example.

Mike Miller <mtmiller>
Project Administrator
Wed 01 Jun 2016 03:17:04 PM UTC, original submission:

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:

If 2rgriddensity(bands[2i+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!

Anonymous

 

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Attached Files
file #37331:  testcase.m added by None (269B - application/octet-stream)
file #37332:  gdbdump added by None (7KiB - application/octet-stream)

 

Depends on the following items: None found

Items that depend on this one: None found

 

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  • -unavailable- added by jwe (Updated the item)
  • -unavailable- added by mtmiller (Posted a comment)
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    Follow 5 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Sun 13 Aug 2017 01:18:31 PM UTCjweSummarysignal package: crash in remez with close frequency band values + differentiator=>[octave forge] (signal) crash in remez with close frequency band values + differentiator
    Thu 02 Jun 2016 03:40:21 AM UTCmtmillerStatusNone=>Confirmed
      SummaryCrash when using signal's remez function for close frequency band values + differentiator=>signal package: crash in remez with close frequency band values + differentiator
    Wed 01 Jun 2016 03:17:04 PM UTCNoneAttached File-=>Added testcase.m, #37331
      Attached File-=>Added gdbdump, #37332

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