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| author | Florian Weimer <fweimer@redhat.com> | 2015-10-15 09:23:07 +0200 |
|---|---|---|
| committer | Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com> | 2016-02-25 16:00:20 -0300 |
| commit | 9f108bbbeb8064a746cd2e1e7079f58fe3508485 (patch) | |
| tree | e27d04f316e1a3e68c0fb5253b913f486f8cfd51 | |
| parent | ed99e5f9cc6471745488f269d16ee5b127944a85 (diff) | |
| download | glibc-9f108bbbeb8064a746cd2e1e7079f58fe3508485.tar.gz glibc-9f108bbbeb8064a746cd2e1e7079f58fe3508485.tar.xz glibc-9f108bbbeb8064a746cd2e1e7079f58fe3508485.zip | |
Always enable pointer guard [BZ #18928]
Honoring the LD_POINTER_GUARD environment variable in AT_SECURE mode
has security implications. This commit enables pointer guard
unconditionally, and the environment variable is now ignored.
[BZ #18928]
* sysdeps/generic/ldsodefs.h (struct rtld_global_ro): Remove
_dl_pointer_guard member.
* elf/rtld.c (_rtld_global_ro): Remove _dl_pointer_guard
initializer.
(security_init): Always set up pointer guard.
(process_envvars): Do not process LD_POINTER_GUARD.
(cherry picked from commit a014cecd82b71b70a6a843e250e06b541ad524f7)
Conflicts:
NEWS
| -rw-r--r-- | ChangeLog | 10 | ||||
| -rw-r--r-- | NEWS | 5 | ||||
| -rw-r--r-- | elf/rtld.c | 15 | ||||
| -rw-r--r-- | sysdeps/generic/ldsodefs.h | 3 |
4 files changed, 18 insertions, 15 deletions
diff --git a/ChangeLog b/ChangeLog index d9cbce76d5..32f9e4a62f 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2016-02-25 Florian Weimer <fweimer@redhat.com> + + [BZ #18928] + * sysdeps/generic/ldsodefs.h (struct rtld_global_ro): Remove + _dl_pointer_guard member. + * elf/rtld.c (_rtld_global_ro): Remove _dl_pointer_guard + initializer. + (security_init): Always set up pointer guard. + (process_envvars): Do not process LD_POINTER_GUARD. + 2015-07-21 Mike Frysinger <vapier@gentoo.org> [BZ #18694] diff --git a/NEWS b/NEWS index b469ad2b50..34daa03661 100644 --- a/NEWS +++ b/NEWS @@ -10,7 +10,10 @@ Version 2.20.1 * The following bugs are resolved with this release: 16009, 16617, 16618, 17266, 17370, 17371, 17460, 17485, 17555, 17625, - 17630, 17801, 18694. + 17630, 17801, 18694, 18928. + +* The LD_POINTER_GUARD environment variable can no longer be used to + disable the pointer guard feature. It is always enabled. * CVE-2015-1472 Under certain conditions wscanf can allocate too little memory for the to-be-scanned arguments and overflow the allocated diff --git a/elf/rtld.c b/elf/rtld.c index d5cace868b..39d3ae2b03 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -162,7 +162,6 @@ struct rtld_global_ro _rtld_global_ro attribute_relro = ._dl_hwcap_mask = HWCAP_IMPORTANT, ._dl_lazy = 1, ._dl_fpu_control = _FPU_DEFAULT, - ._dl_pointer_guard = 1, ._dl_pagesize = EXEC_PAGESIZE, ._dl_inhibit_cache = 0, @@ -709,15 +708,12 @@ security_init (void) #endif /* Set up the pointer guard as well, if necessary. */ - if (GLRO(dl_pointer_guard)) - { - uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random, - stack_chk_guard); + uintptr_t pointer_chk_guard + = _dl_setup_pointer_guard (_dl_random, stack_chk_guard); #ifdef THREAD_SET_POINTER_GUARD - THREAD_SET_POINTER_GUARD (pointer_chk_guard); + THREAD_SET_POINTER_GUARD (pointer_chk_guard); #endif - __pointer_chk_guard_local = pointer_chk_guard; - } + __pointer_chk_guard_local = pointer_chk_guard; /* We do not need the _dl_random value anymore. The less information we leave behind, the better, so clear the @@ -2471,9 +2467,6 @@ process_envvars (enum mode *modep) GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0; break; } - - if (memcmp (envline, "POINTER_GUARD", 13) == 0) - GLRO(dl_pointer_guard) = envline[14] != '0'; break; case 14: diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index e01df84a99..88383edc81 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -582,9 +582,6 @@ struct rtld_global_ro /* List of auditing interfaces. */ struct audit_ifaces *_dl_audit; unsigned int _dl_naudit; - - /* 0 if internal pointer values should not be guarded, 1 if they should. */ - EXTERN int _dl_pointer_guard; }; # define __rtld_global_attribute__ # ifdef IS_IN_rtld |