Bug 1501 – Some effects crash allocating memory for extreme inputs

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Audacity 3.0.3 development began 19th April 2021

Audacity Bugzilla

Bug 1501 - Some effects crash allocating memory for extreme inputs


Summary:	Some effects crash allocating memory for extreme inputs

Status:	RESOLVED QUICKFIXED

Product:	Audacity
Classification:	Unclassified
Component:	Built-in FX
Version:	2.1.3
Hardware:	Per OS All

Importance:	P4 Summary
Assigned To:	Default Assignee for New Bugs

URL:
Keywords:

Depends on:
Blocks:
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Reported:	2016-08-28 11:59 UTC by Paul L
Modified:	2018-08-20 11:51 UTC (History)
CC List:	5 users (show)

See Also:
Steps To Reproduce:	1) Generate some sound, select all, use Echo, make delay 1000000 seconds. 2) Generate 14 hours of silence, select all use Paulstretch, make stretch factor 1 and time resolution 10000. 3) Generate 14 hours of silence, select all, Analyze, Find Clipping, and enter 1000000000 for Start. This causes unhandled exceptions for excessive memory allocation requests for buffers.
Release Note:
First Git SHA:
Group:	---
Workaround:
Closed:	2018-08-20 00:00:00

Flags:	gale: Test‑OK‑Win+ gale: Test‑OK‑Mac+ gale: Test‑OK‑Lin+

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Description Paul L 2016-08-28 11:59:09 UTC

Comment 1 Paul L 2016-08-28 12:02:23 UTC

Described in steps are two known cases where unchecked extreme values of user inputs affect calculation of memory buffer sizes requested from the allocator.

I will fix these two effects with try-catch blocks.  I don't yet know if there are other examples, or what an appropriate general fix at the level of Effect.cpp would be.

Comment 2 Paul L 2016-08-28 12:33:34 UTC

Fixed here, but...

https://github.com/audacity/audacity/commit/36ddd9875713719e2b253a18d23c4341bb4aacf9

... Gale may wish to change the user-visible error messages I added.

Comment 3 Paul L 2016-08-28 15:55:47 UTC

https://github.com/audacity/audacity/commit/38ee7c0e3e3933c2aac19530ea897ad0787893bc

This fixes a similar crash that could happen with Find Clipping of the Analyze menu.

Comment 4 Gale Andrews 2016-08-29 13:10:00 UTC

(In reply to Paul L from comment #1)
I made this a summary bug. It can open and close when necessary if we are making fixes in individual effects for now.  

Fixes seem OK to me (including the message wording) though a user trying to find an extreme value that can actually get processed might argue we should reopen the effect (or not close it and return to it). 

A similar problem is endemic with Nyquist effects that load the entire selection into RAM: bug 1285.