Date: Thu, 4 Oct 2001 12:16:40 +0300 From: Peter Pentchev <roam@ringlet.net> To: freebsd-net@FreeBSD.org Cc: freebsd-audit@FreeBSD.org Subject: [CFR] whois(1) out-of-bound access patch Message-ID: <20011004121640.C1959@ringworld.oblivion.bg>
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Hi,
As described in PR bin/30968, whois(1) may access invalid data when
the whois server returns a non-newline-terminated string.
While it is true that the whois server maintainers should do a better
job of following standards and such, still the 'be liberal in what
you accept' mindset might be applied in this case, to fix what is
ultimately a subtle fgetln(3) use bug :)
Any harm in committing the attached patch? And this - or something
like this - should be done soon; all FreeBSD whois clients currently
display weird behavior when querying .biz domains :\
G'luck,
Peter
--
because I didn't think of a good beginning of it.
Index: src/usr.bin/whois/whois.c
===================================================================
RCS file: /home/ncvs/src/usr.bin/whois/whois.c,v
retrieving revision 1.24
diff -u -r1.24 whois.c
--- src/usr.bin/whois/whois.c 2001/08/05 19:37:12 1.24
+++ src/usr.bin/whois/whois.c 2001/10/04 14:03:33
@@ -51,6 +51,7 @@
#include <arpa/inet.h>
#include <ctype.h>
#include <err.h>
+#include <errno.h>
#include <netdb.h>
#include <stdarg.h>
#include <stdio.h>
@@ -251,7 +252,7 @@
{
FILE *sfi, *sfo;
struct addrinfo *res2;
- char *buf, *nhost, *p;
+ char *abuf, *buf, *nhost, *p;
int i, nomatch, s;
size_t len;
@@ -275,6 +276,16 @@
nhost = NULL;
nomatch = 0;
while ((buf = fgetln(sfi, &len)) != NULL) {
+ abuf = NULL;
+ if ((len == 0) || !isspace(buf[len - 1])) {
+ abuf = calloc(1, len + 1);
+ if (abuf == NULL) {
+ errno = ENOMEM;
+ err(1, "reallocating");
+ }
+ memcpy(abuf, buf, len);
+ buf = abuf;
+ }
while (len && isspace(buf[len - 1]))
buf[--len] = '\0';
@@ -304,6 +315,7 @@
nomatch = 1;
}
printf("%s\n", buf);
+ free(abuf);
}
/* Do second lookup as needed. */
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