Bug 1609351

This looks like a real bug:

* binary must be statically linked
* must pass DSTs through to _dl_init_paths

The problem is that we don't set l for static applications so this has never worked.

With upstream's support for static link maps we will always have a non-NULL main linkmap. So I can clean this code up.

I tested this fixes the issue:

diff --git a/elf/dl-load.c b/elf/dl-load.c
index c51e4b3718..348796c0a8 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -748,9 +748,10 @@ _dl_init_paths (const char *llp)
   max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
   *aelem = NULL;
 
-#ifdef SHARED
   /* This points to the map of the main object.  */
   l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
+
+#ifdef SHARED
   if (l != NULL)
     {
       assert (l->l_type != lt_loaded);

RHEL 7.6 has this guard which prevents failure:

# define DL_DST_REQ_STATIC(l) \
  if ((l) == NULL)                                                            \
    {                                                                         \
      const char *origin = _dl_get_origin ();                                 \
      dst_len = (origin && origin != (char *) -1 ? strlen (origin) : 0);      \
    }                                                                         \
  else
#endif

Which was removed by Maciej's upstream changes precisely to get static link map parity with the shared case.

commit d1d5471579eb0426671bf94f2d71e61dfb204c30
Author: Maciej W. Rozycki <macro>
Date:   Sat Jun 22 00:39:42 2013 +0100

    Remove dead DL_DST_REQ_STATIC code.

So it looks like an incomplete transition, where we missed setting 'l' outside of the #ifdef.

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plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version.

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able to fix it before Fedora 28 is end of life. If you would still like 
to see this bug fixed and are able to reproduce it against a later version 
of Fedora, you are encouraged  change the 'version' to a later Fedora 
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

Fedora 28 changed to end-of-life (EOL) status on 2019-05-28. Fedora 28 is
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Reopening and re-targeting for Fedora 29.

$ uname -a
Linux xxxxxx 5.0.5-200.fc29.x86_64 #1 SMP Wed Mar 27 20:58:04 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
$ LD_LIBRARY_PATH=/foo/'$LIB' ldconfig
Segmentation fault (core dumped)

It's not written here yet, but the issue can be reproduced with any statically linked PIE:

  $ cat > empty.c
  int main(void) { return 1; }

  $ gcc -static-pie empty.c -o empty

  $ file empty
  empty: ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, for GNU/Linux 3.2.0, BuildID[sha1]=95e27090a4d7f3de5e632faf9cedbbd22a4afe57, not stripped, too many notes (256)

  $ ldd empty
          statically linked

  $ LD_LIBRARY_PATH=/foo/'$LIB' ./empty 
  Erreur de segmentation (core dumped)

Reproduced on Fedora 30 (aarch64, which is the only Fedora 30 I have access to ATM):

$ uname -a
Linux xxxxxx 5.0.14-300.fc30.aarch64 #1 SMP Thu May 9 10:16:12 UTC 2019 aarch64 aarch64 aarch64 GNU/Linux
$ LD_LIBRARY_PATH=/foo/'$LIB' ldconfig
Segmentation fault (core dumped)

(aside: I wasn't able to report ldconfig crash through abrt, I've opened the bug #1715110 regarding libreport and statically linked executable).

We are tracking this upstream and will fix it there.

This has been fixed upstream, and I'm going to backport the changes.

Fedora 34 and rawhide fixed. We are not going to fix Fedora 33. Thanks for your understanding.

Great, thanks! I'm using Fedora 34 now so it's fine as far as I'm concerned.