void-packages/srcpkgs/glibc/patches/0022-Ignore-and-remove-LD_H...

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From 3776f38fcd267c127ba5eb222e2c614c191744aa Mon Sep 17 00:00:00 2001
From: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date: Tue, 20 Jun 2017 05:59:17 +0200
Subject: Ignore and remove LD_HWCAP_MASK for AT_SECURE programs (bug #21209)
The LD_HWCAP_MASK environment variable may alter the selection of
function variants for some architectures. For AT_SECURE process it
means that if an outdated routine has a bug that would otherwise not
affect newer platforms by default, LD_HWCAP_MASK will allow that bug
to be exploited.
To be on the safe side, ignore and disable LD_HWCAP_MASK for setuid
binaries.
[BZ #21209]
* elf/rtld.c (process_envvars): Ignore LD_HWCAP_MASK for
AT_SECURE processes.
* sysdeps/generic/unsecvars.h: Add LD_HWCAP_MASK.
* elf/tst-env-setuid.c (test_parent): Test LD_HWCAP_MASK.
(test_child): Likewise.
* elf/Makefile (tst-env-setuid-ENV): Add LD_HWCAP_MASK.
(cherry picked from commit 1c1243b6fc33c029488add276e56570a07803bfd)
diff --git a/ChangeLog b/ChangeLog
index 67ce0aa4de..85f1e0a495 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2017-03-07 Siddhesh Poyarekar <siddhesh@sourceware.org>
+
+ [BZ #21209]
+ * elf/rtld.c (process_envvars): Ignore LD_HWCAP_MASK for
+ AT_SECURE processes.
+ * sysdeps/generic/unsecvars.h: Add LD_HWCAP_MASK.
+ * elf/tst-env-setuid.c (test_parent): Test LD_HWCAP_MASK.
+ (test_child): Likewise.
+ * elf/Makefile (tst-env-setuid-ENV): Add LD_HWCAP_MASK.
+
2017-06-19 Florian Weimer <fweimer@redhat.com>
* elf/rtld.c (audit_list_string): New variable.
diff --git a/NEWS b/NEWS
index 29079e8586..7be238c404 100644
--- a/NEWS
+++ b/NEWS
@@ -13,6 +13,7 @@ The following bugs are resolved with this release:
[21015] Document and fix --enable-bind-now
[21109] Tunables broken on big-endian
[21115] sunrpc: Use-after-free in error path in clntudp_call
+ [21209] Ignore and remove LD_HWCAP_MASK for AT_SECURE programs
[21289] Fix symbol redirect for fts_set
[21386] Assertion in fork for distinct parent PID is incorrect
[21624] Unsafe alloca allows local attackers to alias stack and heap (CVE-2017-1000366)
diff --git a/elf/Makefile b/elf/Makefile
index 61abeb59ee..cc4aeb25b6 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -1398,6 +1398,7 @@ $(objpfx)tst-nodelete-dlclose: $(objpfx)tst-nodelete-dlclose-dso.so
$(objpfx)tst-nodelete-dlclose.out: $(objpfx)tst-nodelete-dlclose-dso.so \
$(objpfx)tst-nodelete-dlclose-plugin.so
-tst-env-setuid-ENV = MALLOC_CHECK_=2 MALLOC_MMAP_THRESHOLD_=4096
+tst-env-setuid-ENV = MALLOC_CHECK_=2 MALLOC_MMAP_THRESHOLD_=4096 \
+ LD_HWCAP_MASK=0xffffffff
tst-env-setuid-tunables-ENV = \
GLIBC_TUNABLES=glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096
diff --git a/elf/rtld.c b/elf/rtld.c
index 369724babe..9362a21e73 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -2534,7 +2534,8 @@ process_envvars (enum mode *modep)
case 10:
/* Mask for the important hardware capabilities. */
- if (memcmp (envline, "HWCAP_MASK", 10) == 0)
+ if (!__libc_enable_secure
+ && memcmp (envline, "HWCAP_MASK", 10) == 0)
GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL,
0, 0);
break;
diff --git a/elf/tst-env-setuid.c b/elf/tst-env-setuid.c
index 6ec3fa5874..eec408eb5d 100644
--- a/elf/tst-env-setuid.c
+++ b/elf/tst-env-setuid.c
@@ -213,6 +213,12 @@ test_child (void)
return 1;
}
+ if (getenv ("LD_HWCAP_MASK") != NULL)
+ {
+ printf ("LD_HWCAP_MASK still set\n");
+ return 1;
+ }
+
return 0;
}
#endif
@@ -233,6 +239,12 @@ test_parent (void)
return 1;
}
+ if (getenv ("LD_HWCAP_MASK") == NULL)
+ {
+ printf ("LD_HWCAP_MASK lost\n");
+ return 1;
+ }
+
return 0;
}
#endif
diff --git a/sysdeps/generic/unsecvars.h b/sysdeps/generic/unsecvars.h
index a74083786e..5ea8a4a259 100644
--- a/sysdeps/generic/unsecvars.h
+++ b/sysdeps/generic/unsecvars.h
@@ -16,6 +16,7 @@
"LD_DEBUG\0" \
"LD_DEBUG_OUTPUT\0" \
"LD_DYNAMIC_WEAK\0" \
+ "LD_HWCAP_MASK\0" \
"LD_LIBRARY_PATH\0" \
"LD_ORIGIN_PATH\0" \
"LD_PRELOAD\0" \
--
2.13.1