KA9Q bug in domain.c

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2 total messages Started by Niel Kempson Sun, 12 Nov 1995 00:00

#1406

Author: Niel Kempson
Date: Sun, 12 Nov 1995 00:00

54 lines
1898 bytes

I've just tracked down a bug in KA9Q.

Symptoms:

    Try to list the dns cache with the command:

        domain cache list

    At this point, the OS/2 version of KA9Q crashes with a SYS3175 access
    violation.

Explanation:

    The docachelist() function in domain.c calls newsession() to create a
    separate "session window" to display the cache listing. 

        static int docachelist(int argc, char *argv[], void *p)
        {
            struct rr *rrp;
            struct session *sp;
            int row;
        
            if((sp = newsession(argv[1],DCLIST)) == NULLSESSION)
            {
                return -1;
            }

    The "dns cache list" command takes no further parameters, so only
    argv[0] is defined - argv[1] is undefined/NULL.

Fix:

    Pass argv[0] to newsession() instead:

        static int docachelist(int argc, char *argv[], void *p)
        {
            struct rr *rrp;
            struct session *sp;
            int row;
        
            if((sp = newsession(argv[0],DCLIST)) == NULLSESSION)
            {
                return -1;
            }

This bug hasn't yet crashed the DOS implementation of KA9Q 2.16d in a DOS
session on my machine, but we know that DOS is quite happy to let
programs read NULL pointers.
 
Niel
-- 
Dr C Niel Kempson
Snowy Owl Systems Limited
E-mail: kempson@snowyowl.co.uk (Internet)

Re: KA9Q bug in domain.c

#1407

Author: Malcolm Muir
Date: Sun, 12 Nov 1995 00:00

17 lines
995 bytes

Niel Kempson (kempson@snowyowl.co.uk) wrote:
> I've just tracked down a bug in KA9Q.

Noted and filed for fixing. Thanks.

> This bug hasn't yet crashed the DOS implementation of KA9Q 2.16d in a DOS
> session on my machine, but we know that DOS is quite happy to let
> programs read NULL pointers.

And we all know the DOS version does some odd things at times :)
Occasionally runnning under Windows or QEMM you get protection errors,
perhaps there is a connection :)

-- 
Malcolm S. Muir
Sunderland
England

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