From ae0a9312c562985838fdd9845ef95fe61e8aa3de Mon Sep 17 00:00:00 2001

From: Jakub Hrozek <jakub.hrozek@posteo.se>

Date: Sun, 1 Apr 2018 10:57:22 +0200

Subject: [PATCH 2/2] Watch for uint32_t overflows

Always use a function that we know will catch out-of-range values for UIDs and

GIDs, which are currently unsigned 32-bit numbers everywhere, and which won't

produce a result that'll silently be truncated if we store the result in a

uid_t or gid_t.

---

 nslcd/common.c | 28 ++++++++++++++++------------

 nslcd/common.h | 27 +++------------------------

 2 files changed, 19 insertions(+), 36 deletions(-)

diff --git a/nslcd/common.c b/nslcd/common.c

index 60be7773d2c809f3177744ced0dd0ba90c86e820..de640b47806757e0bb2e704b3b79f1ecb18bbc45 100644

--- a/nslcd/common.c

+++ b/nslcd/common.c

@@ -338,19 +338,23 @@ unsigned long int binsid2id(const char *binsid)

          ((((unsigned long int)binsid[i + 3]) & 0xff) << 24);

 }

-#ifdef WANT_STRTOUI

-/* provide a strtoui() implementation, similar to strtoul() but returning

-   an range-checked unsigned int instead */

-unsigned int strtoui(const char *nptr, char **endptr, int base)

+/* provide a strtoid() implementation, similar to strtoul() but returning

+   an range-checked uint32_t instead */

+unsigned int strtoid(const char *nptr,char **endptr,int base)

 {

-  unsigned long val;

-  val = strtoul(nptr, endptr, base);

-  if (val > UINT_MAX)

+  long long val;

+  /* use the fact that long long is 64-bit, even on 32-bit systems */

+  val=strtoll(nptr,endptr,base);

+  if (val>UINT32_MAX)

   {

-    errno = ERANGE;

-    return UINT_MAX;

+    errno=ERANGE;

+    return UINT32_MAX;

   }

-  /* If errno was set by strtoul, we'll pass it back as-is */

-  return (unsigned int)val;

+  else if (val < 0)

+  {

+    errno=EINVAL;

+    return UINT32_MAX;

+  }

+  /* If errno was set, we'll pass it back as-is */

+  return (uint32_t)val;

 }

-#endif /* WANT_STRTOUI */

diff --git a/nslcd/common.h b/nslcd/common.h

index 26fcf48ae2a6dc50bc97fab238ecc9a1879342ce..97d386eaf1f6881182729c5d8e46ce30d2d28eba 100644

--- a/nslcd/common.h

+++ b/nslcd/common.h

@@ -161,31 +161,10 @@ void invalidator_do(enum ldap_map_selector map);

 #define BUFLEN_HOSTNAME     256  /* host names or FQDN (and safe version) */

 #define BUFLEN_MESSAGE     1024  /* message strings */

-/* provide strtouid() function alias */

-#if SIZEOF_UID_T == SIZEOF_UNSIGNED_LONG_INT

-#define strtouid (uid_t)strtoul

-#elif SIZEOF_UID_T == SIZEOF_UNSIGNED_LONG_LONG_INT

-#define strtouid (uid_t)strtoull

-#elif SIZEOF_UID_T == SIZEOF_UNSIGNED_INT

-#define WANT_STRTOUI 1

-#define strtouid (uid_t)strtoui

-#else

-#error unable to find implementation for strtouid()

-#endif

-/* provide strtogid() function alias */

-#if SIZEOF_GID_T == SIZEOF_UNSIGNED_LONG_INT

-#define strtogid (gid_t)strtoul

-#elif SIZEOF_GID_T == SIZEOF_UNSIGNED_LONG_LONG_INT

-#define strtogid (gid_t)strtoull

-#elif SIZEOF_GID_T == SIZEOF_UNSIGNED_INT

-#ifndef WANT_STRTOUI

-#define WANT_STRTOUI 1

-#endif

-#define strtogid (gid_t)strtoui

-#else

-#error unable to find implementation for strtogid()

-#endif

+uint32_t strtoid(const char *nptr,char **endptr,int base);

+#define strtouid (uid_t)strtoid

+#define strtogid (gid_t)strtoid

 #ifdef WANT_STRTOUI

 /* provide a strtoui() if it is needed */

-- 

2.14.3