Hi Ingo,

On Fri, Dec 04, 2015 at 12:27:39PM +0100, Ingo Schwarze wrote:
> uint32_t should be preferred because that's the POSIX type, while
> u_int32_t is not standardized.  If you are working on the file
> anyway, i'd recommend to unify all uses to uint32_t.

done.

> __LP64__ that is overly specific and not standardized.  Something
> like this maybe:
> 
>   #if SIZE_MAX <= UINT32_MAX

That sounds nice and gives a better clue why that #if is in place.
I've applied it.

> > I still cast frl_variable_len to u_int32_t for ntohl, but will cast it
> > back to int32_t for a "less than 0" check. This should properly handle
> > error cases when it's been negative to begin with.
> 
> True.  Slightly ugly, but i don't see a better way either.

Looking at UINT32_MAX usage now, I just test for var_len > INT32_MAX.


Tobias

Index: locale/rune.c
===================================================================
RCS file: /cvs/src/lib/libc/locale/rune.c,v
retrieving revision 1.4
diff -u -p -u -p -r1.4 rune.c
--- locale/rune.c       25 May 2014 17:47:04 -0000      1.4
+++ locale/rune.c       4 Dec 2015 20:48:52 -0000
@@ -59,23 +59,31 @@
  * SUCH DAMAGE.
  */
 
+#include <sys/types.h>
+#include <sys/stat.h>
 #include <assert.h>
+#include <errno.h>
+#include <stdint.h>
 #include <stdio.h>
-#include <string.h>
 #include <stdlib.h>
-#include <errno.h>
+#include <string.h>
 #include <wchar.h>
-#include <sys/types.h>
-#include <sys/stat.h>
 #include "rune.h"
 #include "rune_local.h"
 
-static int readrange(_RuneLocale *, _RuneRange *, _FileRuneRange *, void *, 
FILE *);
+#define SAFE_ADD(x, y)                 \
+do {                                   \
+       if ((x) > SIZE_MAX - (y))       \
+               return NULL;            \
+       (x) += (y);                     \
+} while (0);
+
+static int readrange(_RuneLocale *, _RuneRange *, uint32_t, void *, FILE *);
 static void _freeentry(_RuneRange *);
 static void _wctype_init(_RuneLocale *rl);
 
 static int
-readrange(_RuneLocale *rl, _RuneRange *rr, _FileRuneRange *frr, void *lastp,
+readrange(_RuneLocale *rl, _RuneRange *rr, uint32_t nranges, void *lastp,
        FILE *fp)
 {
        uint32_t i;
@@ -84,7 +92,7 @@ readrange(_RuneLocale *rl, _RuneRange *r
 
        re = (_RuneEntry *)rl->rl_variable;
 
-       rr->rr_nranges = ntohl(frr->frr_nranges);
+       rr->rr_nranges = nranges;
        if (rr->rr_nranges == 0) {
                rr->rr_rune_ranges = NULL;
                return 0;
@@ -92,16 +100,16 @@ readrange(_RuneLocale *rl, _RuneRange *r
 
        rr->rr_rune_ranges = re;
        for (i = 0; i < rr->rr_nranges; i++) {
+               if ((void *)re >= lastp)
+                       return -1;
+
                if (fread(&fre, sizeof(fre), 1, fp) != 1)
                        return -1;
 
-               re->re_min = ntohl((u_int32_t)fre.fre_min);
-               re->re_max = ntohl((u_int32_t)fre.fre_max);
-               re->re_map = ntohl((u_int32_t)fre.fre_map);
+               re->re_min = ntohl((uint32_t)fre.fre_min);
+               re->re_max = ntohl((uint32_t)fre.fre_max);
+               re->re_map = ntohl((uint32_t)fre.fre_map);
                re++;
-
-               if ((void *)re > lastp)
-                       return -1;
        }
        rl->rl_variable = re;
        return 0;
@@ -121,6 +129,9 @@ readentry(_RuneRange *rr, FILE *fp)
                        continue;
                }
 
+               if (re[i].re_max < re[i].re_min)
+                       goto fail;
+
                l = re[i].re_max - re[i].re_min + 1;
                re[i].re_rune_types = calloc(l, sizeof(_RuneType));
                if (!re[i].re_rune_types) {
@@ -151,17 +162,20 @@ fail2:
 }
 
 /* XXX: temporary implementation */
-static void
+static int
 find_codeset(_RuneLocale *rl)
 {
        char *top, *codeset, *tail, *ep;
 
+       if (rl->rl_variable == NULL)
+               return 0;
+
        /* end of rl_variable region */
        ep = (char *)rl->rl_variable;
        ep += rl->rl_variable_len;
        rl->rl_codeset = NULL;
        if (!(top = strstr(rl->rl_variable, _RUNE_CODESET)))
-               return;
+               return 0;
        tail = strpbrk(top, " \t");
        codeset = top + sizeof(_RUNE_CODESET) - 1;
        if (tail) {
@@ -173,6 +187,7 @@ find_codeset(_RuneLocale *rl)
                *top = '\0';
                rl->rl_codeset = strdup(codeset);
        }
+       return (rl->rl_codeset == NULL);
 }
 
 void
@@ -183,8 +198,7 @@ _freeentry(_RuneRange *rr)
 
        re = rr->rr_rune_ranges;
        for (i = 0; i < rr->rr_nranges; i++) {
-               if (re[i].re_rune_types)
-                       free(re[i].re_rune_types);
+               free(re[i].re_rune_types);
                re[i].re_rune_types = NULL;
        }
 }
@@ -209,6 +223,7 @@ _Read_RuneMagi(FILE *fp)
        _RuneLocale *rl;
        struct stat sb;
        int x;
+       uint32_t runetype_nranges, maplower_nranges, mapupper_nranges, var_len;
 
        if (fstat(fileno(fp), &sb) < 0)
                return NULL;
@@ -225,10 +240,26 @@ _Read_RuneMagi(FILE *fp)
        if (memcmp(frl.frl_magic, _RUNE_MAGIC_1, sizeof(frl.frl_magic)))
                return NULL;
 
-       hostdatalen = sizeof(*rl) + ntohl((u_int32_t)frl.frl_variable_len) +
-           ntohl(frl.frl_runetype_ext.frr_nranges) * sizeof(_RuneEntry) +
-           ntohl(frl.frl_maplower_ext.frr_nranges) * sizeof(_RuneEntry) +
-           ntohl(frl.frl_mapupper_ext.frr_nranges) * sizeof(_RuneEntry);
+       runetype_nranges = ntohl(frl.frl_runetype_ext.frr_nranges);
+       maplower_nranges = ntohl(frl.frl_maplower_ext.frr_nranges);
+       mapupper_nranges = ntohl(frl.frl_mapupper_ext.frr_nranges);
+       var_len = ntohl((uint32_t)frl.frl_variable_len);
+
+#if SIZE_MAX <= UINT32_MAX
+       if (runetype_nranges > SIZE_MAX / sizeof(_RuneEntry) ||
+           maplower_nranges > SIZE_MAX / sizeof(_RuneEntry) ||
+           mapupper_nranges > SIZE_MAX / sizeof(_RuneEntry))
+               return NULL;
+#endif
+
+       if (var_len > INT32_MAX)
+               return NULL;
+
+       hostdatalen = sizeof(*rl);
+       SAFE_ADD(hostdatalen, var_len);
+       SAFE_ADD(hostdatalen, runetype_nranges * sizeof(_RuneEntry));
+       SAFE_ADD(hostdatalen, maplower_nranges * sizeof(_RuneEntry));
+       SAFE_ADD(hostdatalen, mapupper_nranges * sizeof(_RuneEntry));
 
        if ((hostdata = calloc(hostdatalen, 1)) == NULL)
                return NULL;
@@ -240,65 +271,51 @@ _Read_RuneMagi(FILE *fp)
        memcpy(rl->rl_magic, frl.frl_magic, sizeof(rl->rl_magic));
        memcpy(rl->rl_encoding, frl.frl_encoding, sizeof(rl->rl_encoding));
 
-       rl->rl_invalid_rune = ntohl((u_int32_t)frl.frl_invalid_rune);
-       rl->rl_variable_len = ntohl((u_int32_t)frl.frl_variable_len);
+       /* XXX assumes rune_t = uint32_t */
+       rl->rl_invalid_rune = ntohl((uint32_t)frl.frl_invalid_rune);
+       rl->rl_variable_len = ntohl((uint32_t)frl.frl_variable_len);
 
        for (x = 0; x < _CACHED_RUNES; ++x) {
                rl->rl_runetype[x] = ntohl(frl.frl_runetype[x]);
 
-               /* XXX assumes rune_t = u_int32_t */
-               rl->rl_maplower[x] = ntohl((u_int32_t)frl.frl_maplower[x]);
-               rl->rl_mapupper[x] = ntohl((u_int32_t)frl.frl_mapupper[x]);
-       }
-
-       if (readrange(rl, &rl->rl_runetype_ext, &frl.frl_runetype_ext, lastp, 
fp))
-       {
-               free(hostdata);
-               return NULL;
-       }
-       if (readrange(rl, &rl->rl_maplower_ext, &frl.frl_maplower_ext, lastp, 
fp))
-       {
-               free(hostdata);
-               return NULL;
-       }
-       if (readrange(rl, &rl->rl_mapupper_ext, &frl.frl_mapupper_ext, lastp, 
fp))
-       {
-               free(hostdata);
-               return NULL;
-       }
-
-       if (readentry(&rl->rl_runetype_ext, fp) != 0) {
-               free(hostdata);
-               return NULL;
-       }
+               /* XXX assumes rune_t = uint32_t */
+               rl->rl_maplower[x] = ntohl((uint32_t)frl.frl_maplower[x]);
+               rl->rl_mapupper[x] = ntohl((uint32_t)frl.frl_mapupper[x]);
+       }
+
+       if (readrange(rl, &rl->rl_runetype_ext, runetype_nranges, lastp, fp) ||
+           readrange(rl, &rl->rl_maplower_ext, maplower_nranges, lastp, fp) ||
+           readrange(rl, &rl->rl_mapupper_ext, mapupper_nranges, lastp, fp))
+               goto err;
+
+       if (readentry(&rl->rl_runetype_ext, fp) != 0)
+               goto err;
+
+       if ((uint8_t *)rl->rl_variable + rl->rl_variable_len >
+           (uint8_t *)lastp)
+               goto rune_err;
 
-       if ((u_int8_t *)rl->rl_variable + rl->rl_variable_len >
-           (u_int8_t *)lastp) {
-               _freeentry(&rl->rl_runetype_ext);
-               free(hostdata);
-               return NULL;
-       }
        if (rl->rl_variable_len == 0)
                rl->rl_variable = NULL;
-       else if (fread(rl->rl_variable, rl->rl_variable_len, 1, fp) != 1) {
-               _freeentry(&rl->rl_runetype_ext);
-               free(hostdata);
-               return NULL;
-       }
-       find_codeset(rl);
+       else if (fread(rl->rl_variable, rl->rl_variable_len, 1, fp) != 1)
+               goto rune_err;
+       if (find_codeset(rl))
+               goto rune_err;
        _wctype_init(rl);
 
        /*
         * error if we have junk at the tail, 
         * or if we can't allocate memory.
         */
-       if (ftell(fp) != sb.st_size || __make_ctype_tabs(rl) == -1) {
-               _freeentry(&rl->rl_runetype_ext);
-               free(hostdata);
-               return NULL;
-       }
+       if (ftello(fp) != sb.st_size || __make_ctype_tabs(rl) == -1)
+               goto rune_err;
 
        return(rl);
+rune_err:
+       _freeentry(&rl->rl_runetype_ext);
+err:
+       free(hostdata);
+       return NULL;
 }
 
 void

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