--- /dev/null
+From 6d0ba622891bed9d8394eef1935add53003b12e8 Mon Sep 17 00:00:00 2001
+From: Florian Weimer <fweimer@redhat.com>
+Date: Mon, 19 Jun 2017 22:31:04 +0200
+Subject: [PATCH] ld.so: Reject overly long LD_PRELOAD path elements
+
+[Peter: Drop ChangeLog modification]
+Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
+---
+ elf/rtld.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++------------
+ 1 file changed, 72 insertions(+), 16 deletions(-)
+
+diff --git a/elf/rtld.c b/elf/rtld.c
+index 2269dbec81..86ae20c83f 100644
+--- a/elf/rtld.c
++++ b/elf/rtld.c
+@@ -99,6 +99,35 @@ uintptr_t __pointer_chk_guard_local
+ strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
+ #endif
+
++/* Length limits for names and paths, to protect the dynamic linker,
++ particularly when __libc_enable_secure is active. */
++#ifdef NAME_MAX
++# define SECURE_NAME_LIMIT NAME_MAX
++#else
++# define SECURE_NAME_LIMIT 255
++#endif
++#ifdef PATH_MAX
++# define SECURE_PATH_LIMIT PATH_MAX
++#else
++# define SECURE_PATH_LIMIT 1024
++#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 >= SECURE_NAME_LIMIT || memchr (p, '/', len) != NULL)
++ return false;
++ }
++ return *p != '\0';
++}
+
+ /* List of auditing DSOs. */
+ static struct audit_list
+@@ -718,6 +747,42 @@ 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;
++ char fname[SECURE_PATH_LIMIT];
++
++ 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 != '\0')
++ ++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,
+@@ -1464,23 +1529,8 @@ 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);
+--
+2.11.0
+
--- /dev/null
+From 81b82fb966ffbd94353f793ad17116c6088dedd9 Mon Sep 17 00:00:00 2001
+From: Florian Weimer <fweimer@redhat.com>
+Date: Mon, 19 Jun 2017 22:32:12 +0200
+Subject: [PATCH] ld.so: Reject overly long LD_AUDIT path elements
+
+Also only process the last LD_AUDIT entry.
+
+[Peter: Drop ChangeLog modification]
+Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
+---
+ elf/rtld.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++---------
+ 1 file changed, 105 insertions(+), 15 deletions(-)
+
+diff --git a/elf/rtld.c b/elf/rtld.c
+index 86ae20c83f..65647fb1c8 100644
+--- a/elf/rtld.c
++++ b/elf/rtld.c
+@@ -129,13 +129,91 @@ 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. */
++ char fname[SECURE_NAME_LIMIT];
++};
++
++/* 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
+@@ -1305,11 +1383,13 @@ 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. */
+@@ -1320,9 +1400,14 @@ 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
+@@ -1331,7 +1416,7 @@ 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;
+@@ -1344,7 +1429,7 @@ 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);
+ }
+@@ -1448,10 +1533,7 @@ 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. */
+@@ -1715,7 +1797,7 @@ 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 ();
+@@ -2346,9 +2428,7 @@ 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. */
+@@ -2412,7 +2492,7 @@ 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:
+--
+2.11.0
+
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