From 3c7cd21290cabdadd72984fb69bc51e64ff1002d Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Mon, 19 Jun 2017 18:31:27 +0200 Subject: CVE-2017-1000366: Ignore LD_LIBRARY_PATH for AT_SECURE=1 programs [BZ #21624] LD_LIBRARY_PATH can only be used to reorder system search paths, which is not useful functionality. This makes an exploitable unbounded alloca in _dl_init_paths unreachable for AT_SECURE=1 programs. (cherry picked from commit f6110a8fee2ca36f8e2d2abecf3cba9fa7b8ea7d) --- ChangeLog | 7 +++++++ NEWS | 1 + elf/rtld.c | 3 ++- 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/ChangeLog b/ChangeLog index d44aff0a36..14ff8b8bb3 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2017-06-19 Florian Weimer + + [BZ #21624] + CVE-2017-1000366 + * elf/rtld.c (process_envvars): Ignore LD_LIBRARY_PATH for + __libc_enable_secure. + 2017-05-12 Florian Weimer [BZ #21386] diff --git a/NEWS b/NEWS index d52872323d..29079e8586 100644 --- a/NEWS +++ b/NEWS @@ -15,6 +15,7 @@ The following bugs are resolved with this release: [21115] sunrpc: Use-after-free in error path in clntudp_call [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) Version 2.25 diff --git a/elf/rtld.c b/elf/rtld.c index a036ece956..2fc33a6178 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -2418,7 +2418,8 @@ process_envvars (enum mode *modep) case 12: /* The library search path. */ - if (memcmp (envline, "LIBRARY_PATH", 12) == 0) + if (!__libc_enable_secure + && memcmp (envline, "LIBRARY_PATH", 12) == 0) { library_path = &envline[13]; break; -- cgit v1.2.1