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Message-Id: <199809141027.DAA14681@hub.freebsd.org>
Date: Mon, 14 Sep 1998 03:27:17 -0700 (PDT)
From: sp@alkor.ru
To: freebsd-gnats-submit@FreeBSD.ORG
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Subject: misc/7926: Probable weak code /usr/bin/cksum
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>Number:         7926
>Category:       misc
>Synopsis:       Probable weak code /usr/bin/cksum
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:
>Keywords:
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Sep 14 03:30:00 PDT 1998
>Last-Modified:
>Originator:     Sergey Potapov
>Organization:
Alkor Telecom SPb Russia
>Release:        2.2.6-RELEASE
>Environment:
FreeBSD ws.alkor.ru 2.2.6-RELEASE FreeBSD 2.2.6-RELEASE #0: Fri Apr  3 16:50:57 MSD 1998     sp@backup.alkor.ru:/usr/src/sys/compile/WORKSTAT  i386

>Description:
the code (/usr/src/usr.bin/cksum/crc32.c):

    while ((nr = read(fd, buf, sizeof(buf))))
        for (len += nr, p = buf; nr--; ++p) {
            CRC(crc, *p) ;
            CRC(crc32_total, *p) ;
        }
    if (nr < 0)
        return 1 ;

IMHO may cause infinite loop or crash of utility.
I cannot predict results if read(2) will return -1 everytime.
I did not check other modules there.
>How-To-Repeat:

>Fix:
Probably should use:

    while ((nr = read(fd, buf, sizeof(buf))) > 0)

instead of:

    while ((nr = read(fd, buf, sizeof(buf))))

>Audit-Trail:
>Unformatted:

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