From 8e1472d2c1e25e6eabc2059170731365f6d5b3d1 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Mon, 18 Dec 2017 20:04:13 +0100 Subject: ld.so: Examine GLRO to detect inactive loader [BZ #20204] GLRO (_rtld_global_ro) is read-only after initialization and can therefore not be patched at run time, unlike the hook table addresses and their contents, so this is a desirable hardening feature. The hooks are only needed if ld.so has not been initialized, and this happens only after static dlopen (dlmopen uses a single ld.so object across all namespaces). Reviewed-by: Carlos O'Donell --- dlfcn/dlopenold.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'dlfcn/dlopenold.c') diff --git a/dlfcn/dlopenold.c b/dlfcn/dlopenold.c index a3db500..d899c4e 100644 --- a/dlfcn/dlopenold.c +++ b/dlfcn/dlopenold.c @@ -70,7 +70,7 @@ __dlopen_nocheck (const char *file, int mode) mode |= RTLD_LAZY; args.mode = mode; - if (__glibc_unlikely (_dlfcn_hook != NULL)) + if (!rtld_active ()) return _dlfcn_hook->dlopen (file, mode, RETURN_ADDRESS (0)); return _dlerror_run (dlopen_doit, &args) ? NULL : args.new; -- cgit v1.1