From: cinap_lenrek@felloff.net
To: 9front@9front.org
Subject: Re: [9front] werc memory over flow
Date: Sat, 12 Mar 2022 12:54:38 +0100 [thread overview]
Message-ID: <CC7138DE00DDE7F6259D949AFAE27A21@felloff.net> (raw)
In-Reply-To: <CDCBC180CF87AAF0F4BC5AC7D4F7791B@felloff.net>
actually, i think i found it (by staring at the code).
the code at the done label was unconditionally inserting
NUL terminator, without the final adjbuf() ensuring
theres space for it.
the patch gets rid of the label, so we wont skip the
final adjbuf().
diff d52f25ecdcf1dc8ee8d278c8da44159d82d8dd8f uncommitted
--- a/sys/src/cmd/awk/run.c
+++ b/sys/src/cmd/awk/run.c
@@ -1934,7 +1934,7 @@
}
}
if (*c == 0) /* at end */
- goto done;
+ break;
adjbuf(&buf, &bufsz, 2+pb-buf, recsize, &pb, "gsub");
*pb++ = *c++;
if (pb > buf + bufsz) /* BUG: not sure of this test */
@@ -1962,8 +1962,12 @@
*pb++ = *sptr++;
}
c = patbeg + patlen;
- if ((c[-1] == 0) || (*c == 0))
- goto done;
+ if (c[-1] == 0){
+ c--;
+ break;
+ }
+ if (*c == 0)
+ break;
if (pb > buf + bufsz)
FATAL("gsub result1 %.30s too big; can't happen", buf);
mflag = 1;
@@ -1973,7 +1977,7 @@
adjbuf(&buf, &bufsz, 1+strlen(sptr)+pb-buf, 0, &pb, "gsub");
while ((*pb++ = *sptr++) != 0)
;
- done: if (pb > buf + bufsz)
+ if (pb > buf + bufsz)
FATAL("gsub result2 %.30s too big; can't happen", buf);
*pb = '\0';
setsval(x, buf); /* BUG: should be able to avoid copy + free */
--
cinap
next prev parent reply other threads:[~2022-03-12 12:00 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-11 6:24 william
2022-03-11 6:33 ` ori
2022-03-11 15:18 ` ori
2022-03-12 11:23 ` cinap_lenrek
2022-03-12 11:54 ` cinap_lenrek [this message]
2022-03-12 12:34 ` cinap_lenrek
2022-03-13 7:27 ` william
2022-03-13 21:16 ` cinap_lenrek
2022-03-12 13:27 ` Steve Simon
2022-03-12 14:38 ` Steffen Nurpmeso
2022-03-11 16:49 ` Nick Owens
2022-03-11 20:13 ` cinap_lenrek
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