From: ori@eigenstate.org
To: 9front@9front.org
Cc: 9front@9front.org
Subject: Re: [9front] upas/Mail: fix multiple suicides (use after free, double free) in mbox.c (patch)
Date: Sun, 11 Apr 2021 19:59:35 -0700 [thread overview]
Message-ID: <97FDE9A5306132622D1D4F91D0453FA9@eigenstate.org> (raw)
In-Reply-To: <9F7C695CA1C76DA9023BE33F535E8C8F@9lab.org>
Quoth igor@9lab.org:
> Below is a patch (inline) that fixes two variants of a suicide (use
> after free, double free) in Mail/mbox.c on latest 9front 'Mit
> Fruchtgeschmack' (explanation with reproducible test instructions
> below) when messages are deleted/moved in bulk:
>
> <patch>
> diff -r 4dfbef4fa4ac sys/src/cmd/upas/Mail/mbox.c
> --- a/sys/src/cmd/upas/Mail/mbox.c Sat Apr 03 19:32:47 2021 +0200
> +++ b/sys/src/cmd/upas/Mail/mbox.c Fri Apr 09 02:54:10 2021 +0200
> @@ -675,10 +675,11 @@
> static void
> mbflush(char **, int)
> {
> - int i, j, ln, fd;
> + int i, j, ln, fd, nmesg;
> char *path;
> Mesg *m, *p;
>
> + nmesg = mbox.nmesg;
> path = estrjoin(maildir, "/ctl", nil);
> fd = open(path, OWRITE);
> free(path);
> @@ -708,11 +709,13 @@
> mbredraw(m->child[j], 1, 1);
> }
>
> - for(i = 0, j = 0; i < mbox.nmesg; i++){
> + for(i = 0, j = 0; i < nmesg; i++){
> m = mbox.mesg[i];
> - if((m->state & Szap) != 0)
> + if((m->state & Szap) != 0){
> mesgfree(m);
> - else
> + mbox.mesg[i] = nil;
> + mbox.nmesg--;
> + }else
> mbox.mesg[j++] = m;
> }
I think I prefer this patch:
diff -r 503c5ef2d2b5 sys/src/cmd/upas/Mail/mbox.c
--- a/sys/src/cmd/upas/Mail/mbox.c Sun Apr 11 20:20:41 2021 +0200
+++ b/sys/src/cmd/upas/Mail/mbox.c Sun Apr 11 19:58:55 2021 -0700
@@ -715,6 +715,7 @@
else
mbox.mesg[j++] = m;
}
+ mbox.nmesg = j;
close(fd);
fprint(mbox.ctl, "clean\n");
next prev parent reply other threads:[~2021-04-12 7:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-11 20:19 igor
2021-04-12 2:59 ` ori [this message]
2021-04-12 12:49 ` igor
2021-04-12 15:51 ` cinap_lenrek
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