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| author | Florian Weimer <fweimer@redhat.com> | 2015-10-15 09:23:07 +0200 |
|---|---|---|
| committer | Mike Frysinger <vapier@gentoo.org> | 2015-10-17 00:40:43 -0400 |
| commit | bf6a73fb389728f297d942f403bfeac150249a66 (patch) | |
| tree | e189475e3c11a794953d55ff9bccb577839fc5a7 | |
| parent | 5c4ac5014823e2bc93f74d4a8ac5502f01a9753f (diff) | |
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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)
(cherry picked from commit dc22a1ec157d02529a0b17986679d3f1c122985e)
| -rw-r--r-- | elf/rtld.c | 15 | ||||
| -rw-r--r-- | sysdeps/generic/ldsodefs.h | 3 |
2 files changed, 4 insertions, 14 deletions
diff --git a/elf/rtld.c b/elf/rtld.c index 69873c2368..07e741cfa7 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 7a0fe8dbe4..78e3a97c06 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -592,9 +592,6 @@ 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__ # if IS_IN (rtld) |