elf: Use _dl_catch_error from base namespace in dl-libc.c [BZ #27646]

dlerrror_run in elf/dl-libc.c needs to call GLRO (dl_catch_error)
from the base namespace, just like the exported dlerror
implementation.

Fixes commit b2964eb1d9a6b8ab1250e8a881cf406182da5875 ("dlfcn:
Failures after dlmopen should not terminate process [BZ #24772]").

Backport notes: GLRO (dl_catch_error) is replaced with
_dl_catch_error_ptr to preserve _rtld_global_ro layout.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit c2059edce20c124d1a99f1a94cc52e83b77a917a)

diff --git a/NEWS b/NEWS
index b9e570b4a465d2129fb720a2444f6ce6749c9e63..979a012dbace27cff77d4762cb2a121feed5b44e 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -28,6 +28,7 @@ The following bugs are resolved with this release:
   [27304] pthread_cond_destroy does not pass private flag to futex system calls
   [27537] test-container: Always copy test-specific support files
   [27577] elf/ld.so --help doesn't work
+  [27646] gethostbyname and NSS crashes after dlmopen
   [27648] FAIL: misc/tst-select
   [27651] Performance regression after updating to 2.33
   [27706] select fails to update timeout on error

diff --git a/elf/Makefile b/elf/Makefile
index 509475dd9914e6f389f2be2fd2e8a9f008af2134..4fc3bd8239c8a99b61967ac50b60e55a3e80909a 100644 (file)
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -227,7 +227,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
         tst-single_threaded tst-single_threaded-pthread \
         tst-tls-ie tst-tls-ie-dlmopen argv0test \
         tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask \
-        tst-dlmopen-dlerror
+        tst-dlmopen-dlerror tst-dlmopen-gethostbyname
 #       reldep9
 tests-internal += loadtest unload unload2 circleload1 \
         neededtest neededtest2 neededtest3 neededtest4 \
@@ -349,7 +349,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
                libmarkermod2-1 libmarkermod2-2 \
                libmarkermod3-1 libmarkermod3-2 libmarkermod3-3 \
                libmarkermod4-1 libmarkermod4-2 libmarkermod4-3 libmarkermod4-4 \
-               tst-dlmopen-dlerror-mod \
+               tst-dlmopen-dlerror-mod tst-dlmopen-gethostbyname-mod \
 
 # Most modules build with _ISOMAC defined, but those filtered out
 # depend on internal headers.
@@ -1926,3 +1926,6 @@ $(objpfx)tst-rtld-help.out: $(objpfx)ld.so
        fi; \
        (exit $$status); \
        $(evaluate-test)
+
+$(objpfx)tst-dlmopen-gethostbyname: $(libdl)
+$(objpfx)tst-dlmopen-gethostbyname.out: $(objpfx)tst-dlmopen-gethostbyname-mod.so

diff --git a/elf/dl-libc.c b/elf/dl-libc.c
index ed551f6e56b3cb31ca7c1730722c33cddf72eb98..e2236d87d1df4cfaf004b2cb430bb953dbbbe2c2 100644 (file)
--- a/elf/dl-libc.c
+++ b/elf/dl-libc.c
@@ -43,9 +43,15 @@ dlerror_run (void (*operate) (void *), void *args)
   const char *last_errstring = NULL;
   bool malloced;
 
+#ifdef SHARED
+  int result = (_dl_catch_error_ptr (&objname, &last_errstring, &malloced,
+                                    operate, args)
+               ?: last_errstring != NULL);
+#else
   int result = (_dl_catch_error (&objname, &last_errstring, &malloced,
-                               operate, args)
+                                operate, args)
                ?: last_errstring != NULL);
+#endif
 
   if (result && malloced)
     free ((char *) last_errstring);

diff --git a/elf/tst-dlmopen-gethostbyname-mod.c b/elf/tst-dlmopen-gethostbyname-mod.c
new file mode 100644 (file)
index 0000000..9a68ea5
--- /dev/null
+++ b/elf/tst-dlmopen-gethostbyname-mod.c
@@ -0,0 +1,29 @@
+/* Exercise dlerror_run in elf/dl-libc.c after dlmopen, via NSS.  Helper module.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <netdb.h>
+#include <nss.h>
+
+void
+call_gethostbyname (void)
+{
+  __nss_configure_lookup ("hosts", "files");
+  /* This should not terminate the process due to a missing
+     _nss_files_getcanonname_r symbol.  */
+  gethostbyname ("localhost");
+}

diff --git a/elf/tst-dlmopen-gethostbyname.c b/elf/tst-dlmopen-gethostbyname.c
new file mode 100644 (file)
index 0000000..12deb29
--- /dev/null
+++ b/elf/tst-dlmopen-gethostbyname.c
@@ -0,0 +1,31 @@
+/* Exercise dlerror_run in elf/dl-libc.c after dlmopen, via NSS (bug 27646).
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <support/xdlfcn.h>
+
+static int
+do_test (void)
+{
+  void *handle = xdlmopen (LM_ID_NEWLM, "tst-dlmopen-gethostbyname-mod.so",
+                           RTLD_NOW);
+  void (*call_gethostbyname) (void) = xdlsym (handle, "call_gethostbyname");
+  call_gethostbyname ();
+  return 0;
+}
+
+#include <support/test-driver.c>