Bug 1963710

Description of problem:

When compiled statically, getpwuid(unnamed_uid), causes a program to core dump.

Note: This bug is a re-filing of this one:

  https://bugzilla.redhat.com/show_bug.cgi?id=1842745

That other bug was closed as fixed in F33, but while it may have fixed something upstream, it hasn't actually fixed the reason the bug was filed. So I'm filing this one.

Version-Release number of selected component (if applicable):

$ rpm -q glibc
glibc-2.33-8.fc34.x86_64

How reproducible:

100%

Steps to Reproduce:

1. create this program:

/* === bug.c === */

#include <stdio.h>
#include <sys/types.h>
#include <pwd.h>

int main(int argc, char **argv) {
  printf("call for uid=1 returns: %p\n", getpwuid(1));
  printf("call for uid=500 returns: %p\n", getpwuid(500));
}

/* ============= */

2. Compile it as follows:

gcc --static bug.c -o bug

3. run it

Actual results:

$ ./bug 
call for uid=1 returns: 0x4bd200
Segmentation fault (core dumped)

Expected results:

$ ./bug 
call for uid=1 returns: 0x4bd200
call for uid=500 returns: (nil)

Additional info:

$ gcc -g --static bug.c -o bug
$ gdb ./bug
(gdb) run
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7f0029b in getauxval () from /lib64/libc.so.6
(gdb)  bt
#0  0x00007ffff7f0029b in getauxval () from /lib64/libc.so.6
#1  0x00007ffff6fbe80c in parse_environ_flags.lto_priv ()
   from /lib64/libp11-kit.so.0
#2  0x00007ffff6f291ad in _p11_kit_init () from /lib64/libp11-kit.so.0
#3  0x00000000004879de in call_init ()
#4  0x0000000000487acc in _dl_init ()
#5  0x000000000044ea15 in _dl_catch_exception ()
#6  0x000000000047747a in dl_open_worker ()
#7  0x000000000044e9b8 in _dl_catch_exception ()
#8  0x0000000000476d49 in _dl_open ()
#9  0x000000000044d506 in do_dlopen ()
#10 0x000000000044e9b8 in _dl_catch_exception ()
#11 0x000000000044ea83 in _dl_catch_error ()
#12 0x000000000044d547 in dlerror_run ()
#13 0x000000000044d9fa in __libc_dlopen_mode ()
#14 0x0000000000448db0 in module_load ()
#15 0x00000000004491f5 in __nss_module_get_function ()
#16 0x0000000000448baf in __nss_next2 ()
#17 0x0000000000445a20 in getpwuid_r ()
#18 0x000000000044580b in getpwuid ()
#19 0x00000000004017ba in main (argc=1, argv=0x7fffffffddc8) at bug.c:7