Description of problem:

*** glibc detected *** mandb: double free or corruption (fasttop): 0x00000000026fde30 ***
======= Backtrace: =========
/lib64/libc.so.6[0x3004c788aa]
mandb[0x406124]
mandb[0x403e44]
mandb[0x4041d4]
mandb[0x404e9e]
mandb[0x40beba]
mandb[0x40c3db]
mandb[0x403321]
/lib64/libc.so.6(__libc_start_main+0xed)[0x3004c2143d]
mandb[0x403679]
======= Memory map: ========
00400000-0041f000 r-xp 00000000 08:17 422029258                          /usr/bin/mandb
0061e000-0061f000 rw-p 0001e000 08:17 422029258                          /usr/bin/mandb
0061f000-00622000 rw-p 00000000 00:00 0 
01561000-0270c000 rw-p 00000000 00:00 0                                  [heap]
3000000000-3000021000 r-xp 00000000 08:11 3979416                        /lib64/ld-2.13.90.so
3000220000-3000221000 r--p 00020000 08:11 3979416                        /lib64/ld-2.13.90.so
3000221000-3000222000 rw-p 00021000 08:11 3979416                        /lib64/ld-2.13.90.so
3000222000-3000223000 rw-p 00000000 00:00 0 
3003400000-3003415000 r-xp 00000000 08:11 3944741                        /lib64/libgcc_s-4.6.0-20110419.so.1
3003415000-3003614000 ---p 00015000 08:11 3944741                        /lib64/libgcc_s-4.6.0-20110419.so.1
3003614000-3003615000 rw-p 00014000 08:11 3944741                        /lib64/libgcc_s-4.6.0-20110419.so.1
3004c00000-3004d92000 r-xp 00000000 08:11 3979417                        /lib64/libc-2.13.90.so
3004d92000-3004f92000 ---p 00192000 08:11 3979417                        /lib64/libc-2.13.90.so
3004f92000-3004f96000 r--p 00192000 08:11 3979417                        /lib64/libc-2.13.90.so
3004f96000-3004f97000 rw-p 00196000 08:11 3979417                        /lib64/libc-2.13.90.so
3004f97000-3004f9d000 rw-p 00000000 00:00 0 
300e800000-300e816000 r-xp 00000000 08:11 3979845                        /lib64/libz.so.1.2.5
300e816000-300ea16000 ---p 00016000 08:11 3979845                        /lib64/libz.so.1.2.5
300ea16000-300ea17000 rw-p 00016000 08:11 3979845                        /lib64/libz.so.1.2.5
7f749813f000-7f749dfd0000 r--p 00000000 08:17 279829358                  /usr/lib/locale/locale-archive
7f749dfd0000-7f749dfd4000 rw-p 00000000 00:00 0 
7f749dfd4000-7f749dfe0000 r-xp 00000000 08:17 403512846                  /usr/lib64/libpipeline.so.1.2.0
7f749dfe0000-7f749e1e0000 ---p 0000c000 08:17 403512846                  /usr/lib64/libpipeline.so.1.2.0
7f749e1e0000-7f749e1e1000 rw-p 0000c000 08:17 403512846                  /usr/lib64/libpipeline.so.1.2.0
7f749e1e1000-7f749e1e6000 r-xp 00000000 08:17 441186495                  /usr/lib64/libgdbm.so.3.0.0
7f749e1e6000-7f749e3e5000 ---p 00005000 08:17 441186495                  /usr/lib64/libgdbm.so.3.0.0
7f749e3e5000-7f749e3e6000 rw-p 00004000 08:17 441186495                  /usr/lib64/libgdbm.so.3.0.0
7f749e46d000-7f749e474000 r--s 00000000 08:17 268994114                  /usr/lib64/gconv/gconv-modules.cache
7f749e474000-7f749e492000 r-xp 00000000 08:17 9406526                    /usr/lib64/man-db/libman-2.6.0.2.so
7f749e492000-7f749e691000 ---p 0001e000 08:17 9406526                    /usr/lib64/man-db/libman-2.6.0.2.so
7f749e691000-7f749e693000 rw-p 0001d000 08:17 9406526                    /usr/lib64/man-db/libman-2.6.0.2.so
7f749e693000-7f749e695000 rw-p 00000000 00:00 0 
7f749e695000-7f749e69a000 r-xp 00000000 08:17 531549                     /usr/lib64/man-db/libmandb-2.6.0.2.so
7f749e69a000-7f749e899000 ---p 00005000 08:17 531549                     /usr/lib64/man-db/libmandb-2.6.0.2.so
7f749e899000-7f749e89a000 rw-p 00004000 08:17 531549                     /usr/lib64/man-db/libmandb-2.6.0.2.so
7f749e89a000-7f749e89b000 rw-p 00000000 00:00 0 
7fff2c896000-7fff2c8b7000 rw-p 00000000 00:00 0                          [stack]
7fff2c9d7000-7fff2c9d8000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]
./man-db.cron: line 25: 10121 Aborted                 mandb $OPTS

Version-Release number of selected component (if applicable):
2.6.0.2-1

How reproducible:
100%

Steps to Reproduce:
1. wait till cronjob runs or start manually
2.
3.
  
Actual results:
crashing

Expected results:
working

Additional info:
I tried running under gdb but the result seemed like fork bomb, does it fork for every man page? 

Detaching after fork from child process 7530.
Detaching after fork from child process 7531.
Detaching after fork from child process 7533.

(gdb) bt
#0  0x0000003004c36415 in raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x0000003004c37d2b in abort () at abort.c:92
#2  0x0000003004c723b3 in __libc_message (do_abort=2, fmt=0x3004d5cbe8 "*** glibc detected *** %s: %s: 0x%s ***\n") at ../sysdeps/unix/sysv/linux/libc_fatal.c:186
#3  0x0000003004c788aa in malloc_printerr (action=3, str=0x3004d5cdd8 "double free or corruption (fasttop)", ptr=<optimized out>) at malloc.c:6283
#4  0x0000000000406124 in store_descriptions ()
#5  0x0000000000403e44 in test_manfile ()
#6  0x00000000004041d4 in testmandirs ()
#7  0x0000000000404e9e in create_db ()
#8  0x000000000040beba in mandb ()
#9  0x000000000040c3db in process_manpath ()
#10 0x0000000000403321 in main ()