about summary refs log tree commit diff
path: root/sysdeps/unix/sysv
diff options
context:
space:
mode:
authorMarcin Koƛcielnicki <mwk@0x04.net>2019-11-21 00:20:15 +0100
committerFlorian Weimer <fweimer@redhat.com>2019-11-22 14:09:58 +0100
commitb039fd85db0717aca309b61925d00a5a6547a649 (patch)
tree0d2e5bb4a86694aa15af4e0fe4604e587982bdfb /sysdeps/unix/sysv
parent8337b12d0b80b0f26ec88156b8dd4972a9cb34c3 (diff)
downloadglibc-release/2.23/master.tar.gz
glibc-release/2.23/master.tar.xz
glibc-release/2.23/master.zip
rtld: Check __libc_enable_secure before honoring LD_PREFER_MAP_32BIT_EXEC (CVE-2019-19126) [BZ #25204] release/2.23/master
The problem was introduced in glibc 2.23, in commit
b9eb92ab05204df772eb4929eccd018637c9f3e9
("Add Prefer_MAP_32BIT_EXEC to map executable pages with MAP_32BIT").

(cherry picked from commit d5dfad4326fc683c813df1e37bbf5cf920591c8e)
Diffstat (limited to 'sysdeps/unix/sysv')
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h b/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h
index a759934fdd..b13bba65d2 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h
+++ b/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h
@@ -31,7 +31,8 @@
    environment variable, LD_PREFER_MAP_32BIT_EXEC.  */
 #define EXTRA_LD_ENVVARS \
   case 21:							      \
-    if (memcmp (envline, "PREFER_MAP_32BIT_EXEC", 21) == 0)	      \
+    if (!__libc_enable_secure					      \
+	&& memcmp (envline, "PREFER_MAP_32BIT_EXEC", 21) == 0)	      \
       GLRO(dl_x86_cpu_features).feature[index_Prefer_MAP_32BIT_EXEC]  \
 	|= bit_Prefer_MAP_32BIT_EXEC;				      \
     break;