diff --git a/package/glibc/0002-CVE-2017-1000366-Ignore-LD_LIBRARY_PATH-for-AT_SECUR.patch b/package/glibc/0002-CVE-2017-1000366-Ignore-LD_LIBRARY_PATH-for-AT_SECUR.patch new file mode 100644 index 0000000000..d701294deb --- /dev/null +++ b/package/glibc/0002-CVE-2017-1000366-Ignore-LD_LIBRARY_PATH-for-AT_SECUR.patch @@ -0,0 +1,35 @@ +From f6110a8fee2ca36f8e2d2abecf3cba9fa7b8ea7d Mon Sep 17 00:00:00 2001 +From: Florian Weimer +Date: Mon, 19 Jun 2017 17:09:55 +0200 +Subject: [PATCH] CVE-2017-1000366: Ignore LD_LIBRARY_PATH for AT_SECURE=1 + programs [BZ #21624] + +LD_LIBRARY_PATH can only be used to reorder system search paths, which +is not useful functionality. + +This makes an exploitable unbounded alloca in _dl_init_paths unreachable +for AT_SECURE=1 programs. + +[Peter: Drop ChangeLog modification] +Signed-off-by: Peter Korsgaard +--- + elf/rtld.c | 3 ++- + 1 file changed, 8 insertions(+), 1 deletion(-) + +diff --git a/elf/rtld.c b/elf/rtld.c +index 2446a87680..2269dbec81 100644 +--- a/elf/rtld.c ++++ b/elf/rtld.c +@@ -2422,7 +2422,8 @@ 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; +-- +2.11.0 + diff --git a/package/glibc/0003-ld.so-Reject-overly-long-LD_PRELOAD-path-elements.patch b/package/glibc/0003-ld.so-Reject-overly-long-LD_PRELOAD-path-elements.patch new file mode 100644 index 0000000000..df410931da --- /dev/null +++ b/package/glibc/0003-ld.so-Reject-overly-long-LD_PRELOAD-path-elements.patch @@ -0,0 +1,122 @@ +From 6d0ba622891bed9d8394eef1935add53003b12e8 Mon Sep 17 00:00:00 2001 +From: Florian Weimer +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 +--- + 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 + diff --git a/package/glibc/0004-ld.so-Reject-overly-long-LD_AUDIT-path-elements.patch b/package/glibc/0004-ld.so-Reject-overly-long-LD_AUDIT-path-elements.patch new file mode 100644 index 0000000000..25e937bd10 --- /dev/null +++ b/package/glibc/0004-ld.so-Reject-overly-long-LD_AUDIT-path-elements.patch @@ -0,0 +1,204 @@ +From 81b82fb966ffbd94353f793ad17116c6088dedd9 Mon Sep 17 00:00:00 2001 +From: Florian Weimer +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 +--- + 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 +