sync fmt_scaled.c with OpenBSD

revision 1.13
date: 2017/03/11 23:37:23;  author: djm;  state: Exp;  lines: +14 -1;  commitid: jnFKyHkB3CEiEZ2R;
fix signed integer overflow in scan_scaled. Found by Nicolas Iooss
using AFL against ssh_config. ok deraadt@ millert@
----------------------------
revision 1.12
date: 2013/11/29 19:00:51;  author: deraadt;  state: Exp;  lines: +6 -5;
fairly simple unsigned char casts for ctype
ok krw
----------------------------
revision 1.11
date: 2012/11/12 14:07:20;  author: halex;  state: Exp;  lines: +4 -2;
make scan_scaled set errno to EINVAL rather than ERANGE if it encounters
an invalid multiplier, like the man page says it should

"looks sensible" deraadt@, ok ian@
----------------------------
revision 1.10
date: 2009/06/20 15:00:04;  author: martynas;  state: Exp;  lines: +4 -4;
use llabs instead of the home-grown version;  and some comment changes
ok ian@, millert@
----------------------------

1 files changed, 25 insertions, 9 deletions

diff --git a/openbsd-compat/fmt_scaled.c b/openbsd-compat/fmt_scaled.c
index edd682a49..e5533b2de 100644
--- a/openbsd-compat/fmt_scaled.c
+++ b/openbsd-compat/fmt_scaled.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: fmt_scaled.c,v 1.9 2007/03/20 03:42:52 tedu Exp $     */
+/*      $OpenBSD: fmt_scaled.c,v 1.13 2017/03/11 23:37:23 djm Exp $     */
 
 /*
  * Copyright (c) 2001, 2002, 2003 Ian F. Darwin.  All rights reserved.
@@ -69,7 +69,7 @@ static long long scale_factors[] = {
 
 #define MAX_DIGITS (SCALE_LENGTH * 3)   /* XXX strlen(sprintf("%lld", -1)? */
 
-/** Convert the given input string "scaled" into numeric in "result".
+/* Convert the given input string "scaled" into numeric in "result".
  * Return 0 on success, -1 and errno set on error.
  */
 int
@@ -81,7 +81,7 @@ scan_scaled(char *scaled, long long *result)
         long long scale_fact = 1, whole = 0, fpart = 0;
 
         /* Skip leading whitespace */
-        while (isascii(*p) && isspace(*p))
+        while (isascii((unsigned char)*p) && isspace((unsigned char)*p))
                 ++p;
 
         /* Then at most one leading + or - */
@@ -108,7 +108,8 @@ scan_scaled(char *scaled, long long *result)
          * (but note that E for Exa might look like e to some!).
          * Advance 'p' to end, to get scale factor.
          */
-        for (; isascii(*p) && (isdigit(*p) || *p=='.'); ++p) {
+        for (; isascii((unsigned char)*p) &&
+            (isdigit((unsigned char)*p) || *p=='.'); ++p) {
                 if (*p == '.') {
                         if (fract_digits > 0) { /* oops, more than one '.' */
                                 errno = EINVAL;
@@ -124,6 +125,10 @@ scan_scaled(char *scaled, long long *result)
                                 /* ignore extra fractional digits */
                                 continue;
                         fract_digits++;         /* for later scaling */
+                        if (fpart >= LLONG_MAX / 10) {
+                                errno = ERANGE;
+                                return -1;
+                        }
                         fpart *= 10;
                         fpart += i;
                 } else {                                /* normal digit */
@@ -131,6 +136,10 @@ scan_scaled(char *scaled, long long *result)
                                 errno = ERANGE;
                                 return -1;
                         }
+                        if (whole >= LLONG_MAX / 10) {
+                                errno = ERANGE;
+                                return -1;
+                        }
                         whole *= 10;
                         whole += i;
                 }
@@ -150,17 +159,22 @@ scan_scaled(char *scaled, long long *result)
         /* Validate scale factor, and scale whole and fraction by it. */
         for (i = 0; i < SCALE_LENGTH; i++) {
 
-                /** Are we there yet? */
+                /* Are we there yet? */
                 if (*p == scale_chars[i] ||
-                        *p == tolower(scale_chars[i])) {
+                        *p == tolower((unsigned char)scale_chars[i])) {
 
                         /* If it ends with alphanumerics after the scale char, bad. */
-                        if (isalnum(*(p+1))) {
+                        if (isalnum((unsigned char)*(p+1))) {
                                 errno = EINVAL;
                                 return -1;
                         }
                         scale_fact = scale_factors[i];
 
+                        if (whole >= LLONG_MAX / scale_fact) {
+                                errno = ERANGE;
+                                return -1;
+                        }
+
                         /* scale whole part */
                         whole *= scale_fact;
 
@@ -181,7 +195,9 @@ scan_scaled(char *scaled, long long *result)
                         return 0;
                 }
         }
-        errno = ERANGE;
+
+        /* Invalid unit or character */
+        errno = EINVAL;
         return -1;
 }
 
@@ -196,7 +212,7 @@ fmt_scaled(long long number, char *result)
         unsigned int i;
         unit_type unit = NONE;
 
-        abval = (number < 0LL) ? -number : number;      /* no long long_abs yet */
+        abval = llabs(number);
 
         /* Not every negative long long has a positive representation.
          * Also check for numbers that are just too darned big to format