0000846: msh - break/continue statement within nested loop causes hang or segfault

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Category

Severity

Reproducibility

Date Submitted

Last Update

0000846

[BusyBox] Other

major

always

04-22-06 13:18

03-01-08 01:35

Reporter

John

View Status

public

Assigned To

BusyBox

Priority

normal

Resolution

fixed

Status

closed

Product Version

1.1.x

Summary

0000846: msh - break/continue statement within nested loop causes hang or segfault

Description

To be more exact, break/continue statement within nested loop causes hang or segfault on 2nd/3rd/i.e. >1 iteration.

Additional Information

Minimal sample code that shows the bug:
n=0
while :
do
        while :
        do
                break
        done
        echo iteration
        [ $n = 1 ] && break
        n=`expr $n + 1`
done

Run in ash/bash/ksh it echoes iteration twice and exits.
Run in msh it echoes iteration once and either hangs or segfaults (I've experienced both; there seem to be some randomness involved).

Attached Files

Relationships

Notes
(0005544) vda 03-01-08 00:52	forkexec temporarily sets t->words to processed/expanded list of arguments (I think), does its job, returns to execute(), and execute() restores t->words. This scheme breaks horribly with "break" - it longjmps away out of nested execute() call back to some previous execute(), which was executing "while". Leaving break's t->words clobbered! On next iteration "break" has wrong/corrupted t->words... Fix: do not touch t->words, but separately pass wp as param list to builtins.

(0005554) vda 03-01-08 01:35	Fixed in rev 21144.

Issue History
Date Modified	Username	Field	Change
04-22-06 13:18	John	New Issue
04-22-06 13:18	John	Status	new => assigned
04-22-06 13:18	John	Assigned To	=> BusyBox
03-01-08 00:52	vda	Note Added: 0005544
03-01-08 01:35	vda	Status	assigned => closed
03-01-08 01:35	vda	Note Added: 0005554
03-01-08 01:35	vda	Resolution	open => fixed