[glibc] 01/05: debian/patches/any/local-CVE-2017-1000366-rtld-LD_AUDIT.diff, debian/patches/any/local-CVE-2017-1000366-rtld-LD_LIBRARY_PATH.diff, debian/patches/any/local-CVE-2017-1000366-rtld-LD_PRELOAD.diff: add patches to protect the dynamic linker against stack clashes (CVE-2017-1000366).
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aurel32 pushed a commit to branch sid
in repository glibc.
commit 45e49cdffd538d726cec16949ae379b3fc8ed8c4
Author: Aurelien Jarno <aurelien@aurel32.net>
Date: Sun Jun 18 16:27:39 2017 +0200
debian/patches/any/local-CVE-2017-1000366-rtld-LD_AUDIT.diff, debian/patches/any/local-CVE-2017-1000366-rtld-LD_LIBRARY_PATH.diff, debian/patches/any/local-CVE-2017-1000366-rtld-LD_PRELOAD.diff: add patches to protect the dynamic linker against stack clashes (CVE-2017-1000366).
---
debian/changelog | 5 +
.../any/local-CVE-2017-1000366-rtld-LD_AUDIT.diff | 205 +++++++++++++++++++++
...ocal-CVE-2017-1000366-rtld-LD_LIBRARY_PATH.diff | 33 ++++
.../local-CVE-2017-1000366-rtld-LD_PRELOAD.diff | 111 +++++++++++
debian/patches/series | 3 +
5 files changed, 357 insertions(+)
diff --git a/debian/changelog b/debian/changelog
index 7c1d44e..f5b7553 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -15,6 +15,11 @@ glibc (2.24-12) UNRELEASED; urgency=medium
to fix longjmp on hppa. Closes: #858738.
* debian/sysdeps/mipsel.mk, debian/sysdeps/mips64el.mk: leave the default
GCC ISA level, currently MIPS32R2/MIPS64R2.
+ * debian/patches/any/local-CVE-2017-1000366-rtld-LD_AUDIT.diff,
+ debian/patches/any/local-CVE-2017-1000366-rtld-LD_LIBRARY_PATH.diff,
+ debian/patches/any/local-CVE-2017-1000366-rtld-LD_PRELOAD.diff: add
+ patches to protect the dynamic linker against stack clashes
+ (CVE-2017-1000366).
[ John Paul Adrian Glaubitz ]
* debian/sysdeps/sh3.mk: copy from sh4.mk. Closes: #851867.
diff --git a/debian/patches/any/local-CVE-2017-1000366-rtld-LD_AUDIT.diff b/debian/patches/any/local-CVE-2017-1000366-rtld-LD_AUDIT.diff
new file mode 100644
index 0000000..02c5c92
--- /dev/null
+++ b/debian/patches/any/local-CVE-2017-1000366-rtld-LD_AUDIT.diff
@@ -0,0 +1,205 @@
+From ba67ba3275d47e0080f0e5f09d9f5102c000c97e Mon Sep 17 00:00:00 2001
+Message-Id: <ba67ba3275d47e0080f0e5f09d9f5102c000c97e.1495998948.git.fweimer@redhat.com>
+In-Reply-To: <cover.1495998948.git.fweimer@redhat.com>
+References: <cover.1495998948.git.fweimer@redhat.com>
+From: Florian Weimer <fweimer@redhat.com>
+Date: Sun, 28 May 2017 20:44:52 +0200
+Subject: [PATCH 3/3] rtld: Reject overly long LD_AUDIT path elements
+To: libc-alpha@sourceware.org
+
+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 +116,91 @@ 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[PATH_MAX];
++};
++
++/* 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 < PATH_MAX)
++ {
++ 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
+
diff --git a/debian/patches/any/local-CVE-2017-1000366-rtld-LD_LIBRARY_PATH.diff b/debian/patches/any/local-CVE-2017-1000366-rtld-LD_LIBRARY_PATH.diff
new file mode 100644
index 0000000..88b1925
--- /dev/null
+++ b/debian/patches/any/local-CVE-2017-1000366-rtld-LD_LIBRARY_PATH.diff
@@ -0,0 +1,33 @@
+From 4d009d39ac9ede0369e268554a181b428f177a80 Mon Sep 17 00:00:00 2001
+Message-Id: <4d009d39ac9ede0369e268554a181b428f177a80.1495998948.git.fweimer@redhat.com>
+In-Reply-To: <cover.1495998948.git.fweimer@redhat.com>
+References: <cover.1495998948.git.fweimer@redhat.com>
+From: Florian Weimer <fweimer@redhat.com>
+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: libc-alpha@sourceware.org
+
+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
+
diff --git a/debian/patches/any/local-CVE-2017-1000366-rtld-LD_PRELOAD.diff b/debian/patches/any/local-CVE-2017-1000366-rtld-LD_PRELOAD.diff
new file mode 100644
index 0000000..f6a56df
--- /dev/null
+++ b/debian/patches/any/local-CVE-2017-1000366-rtld-LD_PRELOAD.diff
@@ -0,0 +1,111 @@
+From 65ff0b7a085b85271ec8fde99f542281b495e3bc Mon Sep 17 00:00:00 2001
+Message-Id: <65ff0b7a085b85271ec8fde99f542281b495e3bc.1495998948.git.fweimer@redhat.com>
+In-Reply-To: <cover.1495998948.git.fweimer@redhat.com>
+References: <cover.1495998948.git.fweimer@redhat.com>
+From: Florian Weimer <fweimer@redhat.com>
+Date: Sun, 28 May 2017 20:57:40 +0200
+Subject: [PATCH 2/3] rtld: Reject overly long LD_PRELOAD path elements
+To: libc-alpha@sourceware.org
+
+---
+ 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 +732,42 @@ 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[PATH_MAX];
++
++ while (*p != '\0')
++ {
++ /* Split preload list at space/colon. */
++ size_t len = strcspn (p, " :");
++ if (len > 0 && len < PATH_MAX)
++ {
++ 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
+
diff --git a/debian/patches/series b/debian/patches/series
index 0ae97ba..712d740 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -219,3 +219,6 @@ any/submitted-dlopen-noload.diff
any/submitted-perl-inc.diff
any/submitted-unicode-9.0.0.diff
any/cvs-malloc-hardening.diff
+any/local-CVE-2017-1000366-rtld-LD_LIBRARY_PATH.diff
+any/local-CVE-2017-1000366-rtld-LD_PRELOAD.diff
+any/local-CVE-2017-1000366-rtld-LD_AUDIT.diff
--
Alioth's /usr/local/bin/git-commit-notice on /srv/git.debian.org/git/pkg-glibc/glibc.git
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