elf: Ignore LD_BIND_NOW and LD_BIND_NOT for setuid binaries

To avoid any environment variable to change setuid binaries
semantics.

Checked on x86_64-linux-gnu.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

diff --git a/elf/rtld.c b/elf/rtld.c
index 55cdb4836e7536a2fe40a9779c6e90c04aa00be8..d9a6c33b313b98c436f7b36abaf0b711d5ab5d3d 100644 (file)
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -2604,12 +2604,14 @@ process_envvars (struct dl_main_state *state)
 
        case 8:
          /* Do we bind early?  */
-         if (memcmp (envline, "BIND_NOW", 8) == 0)
+         if (!__libc_enable_secure
+             && memcmp (envline, "BIND_NOW", 8) == 0)
            {
              GLRO(dl_lazy) = envline[9] == '\0';
              break;
            }
-         if (memcmp (envline, "BIND_NOT", 8) == 0)
+         if (! __libc_enable_secure
+             && memcmp (envline, "BIND_NOT", 8) == 0)
            GLRO(dl_bind_not) = envline[9] != '\0';
          break;
 
@@ -2686,6 +2688,8 @@ process_envvars (struct dl_main_state *state)
 
       if (GLRO(dl_debug_mask) != 0
          || GLRO(dl_verbose) != 0
+         || GLRO(dl_lazy) != 1
+         || GLRO(dl_bind_not) != 0
          || state->mode != rtld_mode_normal
          || state->version_info)
        _exit (5);

diff --git a/elf/tst-env-setuid.c b/elf/tst-env-setuid.c
index b1d64ac08517a73205f8dda168e1c41cb0aed955..9fa591a13640c5ebff19a01c794fa5ad71111b40 100644 (file)
--- a/elf/tst-env-setuid.c
+++ b/elf/tst-env-setuid.c
@@ -63,12 +63,12 @@ static const struct envvar_t filtered_envvars[] =
   { "LD_DEBUG_OUTPUT",         "/tmp/some-file" },
   { "LD_WARN",                 FILTERED_VALUE },
   { "LD_VERBOSE",              FILTERED_VALUE },
+  { "LD_BIND_NOW",             "0" },
+  { "LD_BIND_NOT",             "1" },
 };
 
 static const struct envvar_t unfiltered_envvars[] =
 {
-  { "LD_BIND_NOW",             "0" },
-  { "LD_BIND_NOT",             "1" },
   /* Non longer supported option.  */
   { "LD_ASSUME_KERNEL",        UNFILTERED_VALUE },
 };

diff --git a/sysdeps/generic/unsecvars.h b/sysdeps/generic/unsecvars.h
index 8975df4a14570f5c2c119e9a0608c480c2288a67..f1724efe0f1fea7bb155b6025a16fea2f662252e 100644 (file)
--- a/sysdeps/generic/unsecvars.h
+++ b/sysdeps/generic/unsecvars.h
@@ -7,6 +7,8 @@
   "GLIBC_TUNABLES\0"                                                         \
   "HOSTALIASES\0"                                                            \
   "LD_AUDIT\0"                                                               \
+  "LD_BIND_NOT\0"                                                            \
+  "LD_BIND_NOW\0"                                                            \
   "LD_DEBUG\0"                                                               \
   "LD_DEBUG_OUTPUT\0"                                                        \
   "LD_DYNAMIC_WEAK\0"                                                        \