glibc: patch CVE-2017-1000366 (stack clash)

pkgs/development/libraries/glibc/CVE-2017-1000366-rtld-LD_AUDIT.patch

···
+From ba67ba3275d47e0080f0e5f09d9f5102c000c97e Mon Sep 17 00:00:00 2001
+Message-Id: <[e-mail]>
+In-Reply-To: <[e-mail]>
+References: <[e-mail]>
+From: Florian Weimer <[e-mail]>
+Date: Sun, 28 May 2017 20:44:52 +0200
+Subject: [PATCH 3/3] rtld: Reject overly long LD_AUDIT path elements
+To: [e-mail]
+
+Also only process the last LD_AUDIT entry.
+---
+ elf/rtld.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++---------
+ 1 file changed, 95 insertions(+), 15 deletions(-)
+
+diff --git a/elf/rtld.c b/elf/rtld.c
+index 30f0cae..89d8573 100644
+--- a/elf/rtld.c
++++ b/elf/rtld.c
+@@ -116,13 +116,95 @@ dso_name_valid_for_suid (const char *p)
+   return *p != '\0';
+ }
+ 
+-/* List of auditing DSOs.  */
++/* LD_AUDIT variable contents.  Must be processed before the
++   audit_list below.  */
++const char *audit_list_string;
++
++/* Cyclic list of auditing DSOs.  audit_list->next is the first
++   element.  */
+ static struct audit_list
+ {
+   const char *name;
+   struct audit_list *next;
+ } *audit_list;
+ 
++/* Iterator for audit_list_string followed by audit_list.  */
++struct audit_list_iter
++{
++  /* Tail of audit_list_string still needing processing, or NULL.  */
++  const char *audit_list_tail;
++
++  /* The list element returned in the previous iteration.  NULL before
++     the first element.  */
++  struct audit_list *previous;
++
++  /* Scratch buffer for returning a name which is part of
++     audit_list_string.  */
++#ifdef PATH_MAX
++  char fname[PATH_MAX];
++#else
++  char fname[4096];
++#endif
++};
++
++/* Initialize an audit list iterator.  */
++static void
++audit_list_iter_init (struct audit_list_iter *iter)
++{
++  iter->audit_list_tail = audit_list_string;
++  iter->previous = NULL;
++}
++
++/* Iterate through both audit_list_string and audit_list.  */
++static const char *
++audit_list_iter_next (struct audit_list_iter *iter)
++{
++  if (iter->audit_list_tail != NULL)
++    {
++      /* First iterate over audit_list_string.  */
++      while (*iter->audit_list_tail != '\0')
++	{
++	  /* Split audit list at colon.  */
++	  size_t len = strcspn (iter->audit_list_tail, ":");
++	  if (len > 0 && len < sizeof(iter->fname))
++	    {
++	      memcpy (iter->fname, iter->audit_list_tail, len);
++	      iter->fname[len] = '\0';
++	    }
++	  else
++	    /* Do not return this name to the caller.  */
++	    iter->fname[0] = '\0';
++
++	  /* Skip over the substring and the following delimiter.  */
++	  iter->audit_list_tail += len;
++	  if (*iter->audit_list_tail == ':')
++	    ++iter->audit_list_tail;
++
++	  /* If the name is valid, return it.  */
++	  if (dso_name_valid_for_suid (iter->fname))
++	    return iter->fname;
++	  /* Otherwise, wrap around and try the next name.  */
++	}
++      /* Fall through to the procesing of audit_list.  */
++    }
++
++  if (iter->previous == NULL)
++    {
++      if (audit_list == NULL)
++	/* No pre-parsed audit list.  */
++	return NULL;
++      /* Start of audit list.  The first list element is at
++	 audit_list->next (cyclic list).  */
++      iter->previous = audit_list->next;
++      return iter->previous->name;
++    }
++  if (iter->previous == audit_list)
++    /* Cyclic list wrap-around.  */
++    return NULL;
++  iter->previous = iter->previous->next;
++  return iter->previous->name;
++}
++
+ #ifndef HAVE_INLINED_SYSCALLS
+ /* Set nonzero during loading and initialization of executable and
+    libraries, cleared before the executable's entry point runs.  This
+@@ -1290,11 +1368,13 @@ of this helper program; chances are you did not intend to run this program.\n\
+     GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
+ 
+   /* If we have auditing DSOs to load, do it now.  */
+-  if (__glibc_unlikely (audit_list != NULL))
++  bool need_security_init = true;
++  if (__glibc_unlikely (audit_list != NULL)
++      || __glibc_unlikely (audit_list_string != NULL))
+     {
+-      /* Iterate over all entries in the list.  The order is important.  */
+       struct audit_ifaces *last_audit = NULL;
+-      struct audit_list *al = audit_list->next;
++      struct audit_list_iter al_iter;
++      audit_list_iter_init (&al_iter);
+ 
+       /* Since we start using the auditing DSOs right away we need to
+ 	 initialize the data structures now.  */
+@@ -1305,9 +1385,14 @@ of this helper program; chances are you did not intend to run this program.\n\
+ 	 use different values (especially the pointer guard) and will
+ 	 fail later on.  */
+       security_init ();
++      need_security_init = false;
+ 
+-      do
++      while (true)
+ 	{
++	  const char *name = audit_list_iter_next (&al_iter);
++	  if (name == NULL)
++	    break;
++
+ 	  int tls_idx = GL(dl_tls_max_dtv_idx);
+ 
+ 	  /* Now it is time to determine the layout of the static TLS
+@@ -1316,7 +1401,7 @@ of this helper program; chances are you did not intend to run this program.\n\
+ 	     no DF_STATIC_TLS bit is set.  The reason is that we know
+ 	     glibc will use the static model.  */
+ 	  struct dlmopen_args dlmargs;
+-	  dlmargs.fname = al->name;
++	  dlmargs.fname = name;
+ 	  dlmargs.map = NULL;
+ 
+ 	  const char *objname;
+@@ -1329,7 +1414,7 @@ of this helper program; chances are you did not intend to run this program.\n\
+ 	    not_loaded:
+ 	      _dl_error_printf ("\
+ ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
+-				al->name, err_str);
++				name, err_str);
+ 	      if (malloced)
+ 		free ((char *) err_str);
+ 	    }
+@@ -1433,10 +1518,7 @@ ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
+ 		  goto not_loaded;
+ 		}
+ 	    }
+-
+-	  al = al->next;
+ 	}
+-      while (al != audit_list->next);
+ 
+       /* If we have any auditing modules, announce that we already
+ 	 have two objects loaded.  */
+@@ -1700,7 +1782,7 @@ ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
+   if (tcbp == NULL)
+     tcbp = init_tls ();
+ 
+-  if (__glibc_likely (audit_list == NULL))
++  if (__glibc_likely (need_security_init))
+     /* Initialize security features.  But only if we have not done it
+        earlier.  */
+     security_init ();
+@@ -2331,9 +2413,7 @@ process_dl_audit (char *str)
+   char *p;
+ 
+   while ((p = (strsep) (&str, ":")) != NULL)
+-    if (p[0] != '\0'
+-	&& (__builtin_expect (! __libc_enable_secure, 1)
+-	    || strchr (p, '/') == NULL))
++    if (dso_name_valid_for_suid (p))
+       {
+ 	/* This is using the local malloc, not the system malloc.  The
+ 	   memory can never be freed.  */
+@@ -2397,7 +2477,7 @@ process_envvars (enum mode *modep)
+ 	      break;
+ 	    }
+ 	  if (memcmp (envline, "AUDIT", 5) == 0)
+-	    process_dl_audit (&envline[6]);
++	    audit_list_string = &envline[6];
+ 	  break;
+ 
+ 	case 7:
+-- 
+2.9.4
+

pkgs/development/libraries/glibc/CVE-2017-1000366-rtld-LD_LIBRARY_PATH.patch

···
+From 4d009d39ac9ede0369e268554a181b428f177a80 Mon Sep 17 00:00:00 2001
+Message-Id: <[e-mail]>
+In-Reply-To: <[e-mail]>
+References: <[e-mail]>
+From: Florian Weimer <[e-mail]>
+Date: Sun, 28 May 2017 20:37:40 +0200
+Subject: [PATCH 1/3] rtld: Completely ignore LD_LIBRARY_PATH for AT_SECURE=1
+ programs
+To: [e-mail]
+
+LD_LIBRARY_PATH can only be used to reorder system search paths, which
+is not useful functionality.
+---
+ elf/rtld.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/elf/rtld.c b/elf/rtld.c
+index 319ef06..824b6cf 100644
+--- a/elf/rtld.c
++++ b/elf/rtld.c
+@@ -2419,7 +2419,8 @@ process_envvars (enum mode *modep)
+ 
+ 	case 12:
+ 	  /* The library search path.  */
+-	  if (memcmp (envline, "LIBRARY_PATH", 12) == 0)
++	  if (!__libc_enable_secure
++	      && memcmp (envline, "LIBRARY_PATH", 12) == 0)
+ 	    {
+ 	      library_path = &envline[13];
+ 	      break;
+-- 
+2.9.4
+

pkgs/development/libraries/glibc/CVE-2017-1000366-rtld-LD_PRELOAD.patch

···
+From 65ff0b7a085b85271ec8fde99f542281b495e3bc Mon Sep 17 00:00:00 2001
+Message-Id: <[e-mail]>
+In-Reply-To: <[e-mail]>
+References: <[e-mail]>
+From: Florian Weimer <[e-mail]>
+Date: Sun, 28 May 2017 20:57:40 +0200
+Subject: [PATCH 2/3] rtld: Reject overly long LD_PRELOAD path elements
+To: [e-mail]
+
+---
+ elf/rtld.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++---------------
+ 1 file changed, 53 insertions(+), 16 deletions(-)
+
+diff --git a/elf/rtld.c b/elf/rtld.c
+index 824b6cf..30f0cae 100644
+--- a/elf/rtld.c
++++ b/elf/rtld.c
+@@ -99,6 +99,22 @@ uintptr_t __pointer_chk_guard_local
+ strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
+ #endif
+ 
++/* Check that AT_SECURE=0, or that the passed name does not contain
++   directories and is not overly long.  Reject empty names
++   unconditionally.  */
++static bool
++dso_name_valid_for_suid (const char *p)
++{
++  if (__glibc_unlikely (__libc_enable_secure))
++    {
++      /* Ignore pathnames with directories for AT_SECURE=1
++	 programs, and also skip overlong names.  */
++      size_t len = strlen (p);
++      if (len >= NAME_MAX || memchr (p, '/', len) != NULL)
++	return false;
++    }
++  return *p != '\0';
++}
+ 
+ /* List of auditing DSOs.  */
+ static struct audit_list
+@@ -716,6 +732,46 @@ static const char *preloadlist attribute_relro;
+ /* Nonzero if information about versions has to be printed.  */
+ static int version_info attribute_relro;
+ 
++/* The LD_PRELOAD environment variable gives list of libraries
++   separated by white space or colons that are loaded before the
++   executable's dependencies and prepended to the global scope list.
++   (If the binary is running setuid all elements containing a '/' are
++   ignored since it is insecure.)  Return the number of preloads
++   performed.  */
++unsigned int
++handle_ld_preload (const char *preloadlist, struct link_map *main_map)
++{
++  unsigned int npreloads = 0;
++  const char *p = preloadlist;
++#ifdef PATH_MAX
++  char fname[PATH_MAX];
++#else
++  char fname[4096];
++#endif
++
++  while (*p != '\0')
++    {
++      /* Split preload list at space/colon.  */
++      size_t len = strcspn (p, " :");
++      if (len > 0 && len < sizeof(fname))
++	{
++	  memcpy (fname, p, len);
++	  fname[len] = '\0';
++	}
++      else
++	fname[0] = '\0';
++
++      /* Skip over the substring and the following delimiter.  */
++      p += len;
++      if (*p == ' ' || *p == ':')
++	++p;
++
++      if (dso_name_valid_for_suid (fname))
++	npreloads += do_preload (fname, main_map, "LD_PRELOAD");
++    }
++  return npreloads;
++}
++
+ static void
+ dl_main (const ElfW(Phdr) *phdr,
+ 	 ElfW(Word) phnum,
+@@ -1462,23 +1514,8 @@ ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
+ 
+   if (__glibc_unlikely (preloadlist != NULL))
+     {
+-      /* The LD_PRELOAD environment variable gives list of libraries
+-	 separated by white space or colons that are loaded before the
+-	 executable's dependencies and prepended to the global scope
+-	 list.  If the binary is running setuid all elements
+-	 containing a '/' are ignored since it is insecure.  */
+-      char *list = strdupa (preloadlist);
+-      char *p;
+-
+       HP_TIMING_NOW (start);
+-
+-      /* Prevent optimizing strsep.  Speed is not important here.  */
+-      while ((p = (strsep) (&list, " :")) != NULL)
+-	if (p[0] != '\0'
+-	    && (__builtin_expect (! __libc_enable_secure, 1)
+-		|| strchr (p, '/') == NULL))
+-	  npreloads += do_preload (p, main_map, "LD_PRELOAD");
+-
++      npreloads += handle_ld_preload (preloadlist, main_map);
+       HP_TIMING_NOW (stop);
+       HP_TIMING_DIFF (diff, start, stop);
+       HP_TIMING_ACCUM_NT (load_time, diff);
+-- 
+2.9.4
+

pkgs/development/libraries/glibc/common.nix

···
          "/bin:/usr/bin", which is inappropriate on NixOS machines. This
          patch extends the search path by "/run/current-system/sw/bin". */
       ./fix_path_attribute_in_getconf.patch
+
+      /* Stack Clash */
+      ./CVE-2017-1000366-rtld-LD_LIBRARY_PATH.patch
+      ./CVE-2017-1000366-rtld-LD_PRELOAD.patch
+      ./CVE-2017-1000366-rtld-LD_AUDIT.patch
     ]
       ++ lib.optional stdenv.isi686 ./fix-i686-memchr.patch;