| From a014cecd82b71b70a6a843e250e06b541ad524f7 Mon Sep 17 00:00:00 2001 |
| From: Florian Weimer <fweimer@redhat.com> |
| Date: Thu, 15 Oct 2015 09:23:07 +0200 |
| Subject: [PATCH] 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. |
| |
| Upstream-Status: Backport |
| CVE: CVE-2015-8777 |
| [Yocto # 8980] |
| |
| https://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commit;h=a014cecd82b71b70a6a843e250e06b541ad524f7 |
| |
| Signed-off-by: Armin Kuster <akuster@mvista.com> |
| |
| --- |
| ChangeLog | 10 ++++++++++ |
| NEWS | 13 ++++++++----- |
| elf/rtld.c | 15 ++++----------- |
| sysdeps/generic/ldsodefs.h | 3 --- |
| 4 files changed, 22 insertions(+), 19 deletions(-) |
| |
| Index: git/ChangeLog |
| =================================================================== |
| --- git.orig/ChangeLog |
| +++ git/ChangeLog |
| @@ -1,3 +1,14 @@ |
| +2015-10-15 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. |
| + |
| + |
| 2015-08-10 Maxim Ostapenko <m.ostapenko@partner.samsung.com> |
| |
| [BZ #18778] |
| Index: git/NEWS |
| =================================================================== |
| --- git.orig/NEWS |
| +++ git/NEWS |
| @@ -34,7 +34,10 @@ Version 2.22 |
| 18533, 18534, 18536, 18539, 18540, 18542, 18544, 18545, 18546, 18547, |
| 18549, 18553, 18557, 18558, 18569, 18583, 18585, 18586, 18592, 18593, |
| 18594, 18602, 18612, 18613, 18619, 18633, 18635, 18641, 18643, 18648, |
| - 18657, 18676, 18694, 18696. |
| + 18657, 18676, 18694, 18696, 18928. |
| + |
| +* The LD_POINTER_GUARD environment variable can no longer be used to |
| + disable the pointer guard feature. It is always enabled. |
| |
| * Cache information can be queried via sysconf() function on s390 e.g. with |
| _SC_LEVEL1_ICACHE_SIZE as argument. |
| Index: git/elf/rtld.c |
| =================================================================== |
| --- git.orig/elf/rtld.c |
| +++ git/elf/rtld.c |
| @@ -163,7 +163,6 @@ struct rtld_global_ro _rtld_global_ro at |
| ._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, |
| |
| @@ -710,15 +709,12 @@ 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 |
| @@ -2478,9 +2474,6 @@ 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: |
| Index: git/sysdeps/generic/ldsodefs.h |
| =================================================================== |
| --- git.orig/sysdeps/generic/ldsodefs.h |
| +++ git/sysdeps/generic/ldsodefs.h |
| @@ -600,9 +600,6 @@ 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) |