From ff38e1986084c3ed1e98effb96e3de66ec809b3b Mon Sep 17 00:00:00 2001 From: rwatson Date: Sun, 15 Jun 2003 06:26:08 +0000 Subject: [PATCH] Tighten up the string->integer conversion in sysctl(8): (1) Reject zero-length strings for CTLTYPE_INT, _UINT, _LONG, _ULONG. Do not silently convert to 0. (2) When converting CTLTYPE_INT, _UINT, _LONG, and _ULONG, check the end pointer generated by strtol() and strtoul() rather than discarding it. Reject the string if either none of the string was useful for conversion to an integer, or if there was trailing garbage. I.e., we will not allow you to set a numeric sysctl to a value unless we can completely convert the string argument to a numeric value. I tripped over this when I put the following in /etc/sysctl.conf: kern.maxfiles="4000" Ouch. --- sbin/sysctl/sysctl.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-) diff --git a/sbin/sysctl/sysctl.c b/sbin/sysctl/sysctl.c index 7442a3213121..787a489edeb9 100644 --- a/sbin/sysctl/sysctl.c +++ b/sbin/sysctl/sysctl.c @@ -163,7 +163,7 @@ parse(char *string) size_t newsize = 0; quad_t quadval; int mib[CTL_MAXNAME]; - char *cp, *bufp, buf[BUFSIZ], fmt[BUFSIZ]; + char *cp, *bufp, buf[BUFSIZ], *endptr, fmt[BUFSIZ]; u_int kind; bufp = buf; @@ -198,25 +198,45 @@ parse(char *string) if (!(kind&CTLFLAG_WR)) errx(1, "oid '%s' is read only", bufp); + + if ((kind & CTLTYPE) == CTLTYPE_INT || + (kind & CTLTYPE) == CTLTYPE_UINT || + (kind & CTLTYPE) == CTLTYPE_LONG || + (kind & CTLTYPE) == CTLTYPE_ULONG) { + if (strlen(newval) == 0) + errx(1, "empty numeric value"); + } switch (kind & CTLTYPE) { case CTLTYPE_INT: - intval = (int) strtol(newval, NULL, 0); + intval = (int) strtol(newval, &endptr, 0); + if (endptr == newval || *endptr != '\0') + errx(1, "invalid integer '%s'", + newval); newval = &intval; newsize = sizeof(intval); break; case CTLTYPE_UINT: - uintval = (int) strtoul(newval, NULL, 0); + uintval = (int) strtoul(newval, &endptr, 0); + if (endptr == newval || *endptr != '\0') + errx(1, "invalid unsigned integer '%s'", + newval); newval = &uintval; newsize = sizeof uintval; break; case CTLTYPE_LONG: - longval = strtol(newval, NULL, 0); + longval = strtol(newval, &endptr, 0); + if (endptr == newval || *endptr != '\0') + errx(1, "invalid long integer '%s'", + newval); newval = &longval; newsize = sizeof longval; break; case CTLTYPE_ULONG: - ulongval = strtoul(newval, NULL, 0); + ulongval = strtoul(newval, &endptr, 0); + if (endptr == newval || *endptr != '\0') + errx(1, "invalid unsigned long integer" + " '%s'", newval); newval = &ulongval; newsize = sizeof ulongval; break;