Bug 104146 - Fault pointer in "watch"
Summary: Fault pointer in "watch"
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: procps   
(Show other bugs)
Version: 9
Hardware: All
OS: Linux
medium
high
Target Milestone: ---
Assignee: Daniel Walsh
QA Contact: Brian Brock
URL:
Whiteboard:
Keywords:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2003-09-10 15:01 UTC by JW
Modified: 2007-04-18 16:57 UTC (History)
0 users

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Environment:
Last Closed: 2004-02-11 13:42:06 UTC
Type: ---
Regression: ---
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Documentation: ---
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
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Description JW 2003-09-10 15:01:45 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (compatible; MSIE 5.01; Windows 98;)

Description of problem:
Here is the code in question:

        for (; optind < argc; optind++) {
                int s = strlen(argv[optind]);
                char *endp = &command[command_length];
                *endp = ' ';
                command_length += s + 1;
                command = realloc(command, command_length + 1);
                strcpy(endp + 1, argv[optind]);
        }

Study it carefully.  Looks fine doesn't it.
Well it isn't.

The 'endp' is set to point somewhere in relation to 'command'
Then 'command' is changed via realloc.
Then 'endp' is used again like nothing has changed!


Version-Release number of selected component (if applicable):
2.0.13-8

How reproducible:
Always

Steps to Reproduce:
1. Read the code
2. 
3.
    

Actual Results:  Depends on realloc/malloc implementation.
At worse segmentation error, but usually just garbled result.
Unless your system allocate memory in rather large chunks.

Additional info:

Comment 1 Alexander Larsson 2003-09-25 09:01:55 UTC
This is fixed in 2.0.16, we need to upgrade.


Comment 2 Pete Zaitcev 2003-10-08 19:35:06 UTC
*** Bug 106399 has been marked as a duplicate of this bug. ***

Comment 3 Pete Zaitcev 2003-10-08 19:37:41 UTC
Eek. Ignore a mistaken dup.


Comment 4 Daniel Walsh 2004-02-11 13:42:06 UTC
Fixed in latest release 3.1.15


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