diff options
Diffstat (limited to 'gnu/packages/patches/glibc-CVE-2017-1000366-pt2.patch')
| -rw-r--r-- | gnu/packages/patches/glibc-CVE-2017-1000366-pt2.patch | 274 |
1 files changed, 96 insertions, 178 deletions
diff --git a/gnu/packages/patches/glibc-CVE-2017-1000366-pt2.patch b/gnu/packages/patches/glibc-CVE-2017-1000366-pt2.patch index 3d8f6d2bf8..4b859c4bfd 100644 --- a/gnu/packages/patches/glibc-CVE-2017-1000366-pt2.patch +++ b/gnu/packages/patches/glibc-CVE-2017-1000366-pt2.patch @@ -1,206 +1,124 @@ -From 81b82fb966ffbd94353f793ad17116c6088dedd9 Mon Sep 17 00:00:00 2001 +From 6d0ba622891bed9d8394eef1935add53003b12e8 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. +Date: Mon, 19 Jun 2017 22:31:04 +0200 +Subject: [PATCH] ld.so: Reject overly long LD_PRELOAD path elements patch from: -https://sourceware.org/git/?p=glibc.git;a=commit;h=81b82fb966ffbd94353f793ad17116c6088dedd9 +https://sourceware.org/git/?p=glibc.git;a=patch;h=6d0ba622891bed9d8394eef1935add53003b12e8 --- - ChangeLog | 11 +++++++ - elf/rtld.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++--------- - 2 files changed, 106 insertions(+), 15 deletions(-) + ChangeLog | 7 ++++++ + elf/rtld.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++------------ + 2 files changed, 73 insertions(+), 16 deletions(-) diff --git a/elf/rtld.c b/elf/rtld.c -index 86ae20c..65647fb 100644 +index 2269dbe..86ae20c 100644 --- a/elf/rtld.c +++ b/elf/rtld.c -@@ -129,13 +129,91 @@ dso_name_valid_for_suid (const char *p) - return *p != '\0'; - } +@@ -99,6 +99,35 @@ uintptr_t __pointer_chk_guard_local + strong_alias (__pointer_chk_guard_local, __pointer_chk_guard) + #endif --/* List of auditing DSOs. */ -+/* LD_AUDIT variable contents. Must be processed before the -+ audit_list below. */ -+const char *audit_list_string; ++/* 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 + -+/* Cyclic list of auditing DSOs. audit_list->next is the first -+ element. */ ++/* 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 - { - const char *name; - struct audit_list *next; - } *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; -+/* 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) ++/* 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) +{ -+ iter->audit_list_tail = audit_list_string; -+ iter->previous = NULL; -+} ++ unsigned int npreloads = 0; ++ const char *p = preloadlist; ++ char fname[SECURE_PATH_LIMIT]; + -+/* 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) ++ while (*p != '\0') + { -+ /* First iterate over audit_list_string. */ -+ while (*iter->audit_list_tail != '\0') ++ /* Split preload list at space/colon. */ ++ size_t len = strcspn (p, " :"); ++ if (len > 0 && len < sizeof (fname)) + { -+ /* 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. */ ++ memcpy (fname, p, len); ++ fname[len] = '\0'; + } -+ /* Fall through to the procesing of audit_list. */ -+ } ++ else ++ fname[0] = '\0'; + -+ 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; ++ /* 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"); + } -+ if (iter->previous == audit_list) -+ /* Cyclic list wrap-around. */ -+ return NULL; -+ iter->previous = iter->previous->next; -+ return iter->previous->name; ++ return npreloads; +} + - #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 (); + 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 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)) + if (__glibc_unlikely (preloadlist != 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; - } - } +- /* 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; - -- 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: + 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); -- 2.9.3 |