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Date: Mon, 17 Jul 2000 00:17:07 -0700 (PDT)
From: chucha@jam.tario.ru
To: freebsd-gnats-submit@FreeBSD.org
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Subject: misc/19975: fgets() and fread() on file without reading rights leads to SEGV
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>Number:         19975
>Category:       misc
>Synopsis:       fgets() and fread() on file without reading rights leads to SEGV
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Jul 17 00:20:01 PDT 2000
>Closed-Date:
>Last-Modified:
>Originator:     Pavel Chuchkalov
>Release:        3.0 and 3.2 ugraded to 4.0
>Organization:
-
>Environment:
FreeBSD 4.0-RELEASE i386
>Description:
If in program file is open, and this file does not have rights to read, fgets() and fread() will cause segmentation violation. fgets() and fread() on "failed" FILE* returned by fopen() crashes program also (use the source code below but do not 'touch test') - stupid but possible programmer's error. I don't know about read() call and others.
>How-To-Repeat:


#include <stdio.h>

extern int errno;

main() {
	FILE *file;
	char str[1024];

	file = fopen("test", "r");
//	fgets(str, sizeof(str), file);
//	fread(str, sizeof(str), 1, file);

	printf("feof(file) = %d, errno = %d, ferror(file) = %d\n",
		feof(file), errno, ferror(file));
}

>Fix:
I'm not competent in fixing, but I would like to be :) Please, CC: chucha@jam.tario.ru while discussing this problem, or tell me maillist (oh, how I'm tired of all of them! ;) where this problem will be discussed. Or, if I'm really wrong and my trouble is only in my mind, let me know also... Good luck!

>Release-Note:
>Audit-Trail:
>Unformatted:


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