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Description of problem:

Tcpdump segfaults with --help option on ppc64. The issue is in getopt_long function and bad parameter with list of possible options which is not properly terminated.

# ltrace tcpdump --help
(0x80086a2a40, 0, 1, 0, 0xfffffffffeff0000)                                                                                         = 0x80086a2a40
__libc_start_main(2, 0xfffd41c5498, 0xfffd41c54b0, 0xfffd41c55d8, 0x80086a03f0 <unfinished ...>
strrchr("tcpdump", '/')                                                                                                             = NULL
getopt_long(2, 0xfffd41c5498, "aAB:c:C:dDeE:fF:G:i:Ij:JKlLm:M:n"..., 0x100cf248, NULL <unfinished ...>
--- SIGSEGV (Segmentation fault) ---
+++ killed by SIGSEGV +++

Coredump appears only on ppc64, but the code is the same for all architectures, so the fact there is no segfault on the other architectures is coincidence.

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

tcpdump-4.0.0-8.20090921gitdf3cb4.2.el6

How reproducible:

100% on ppc64

Steps to Reproduce:
1. Run command tpcdump --help on ppc64.

# tcpdump --help
Segmentation fault (core dumped)

Actual results:

Segfault.

Expected results:

No segfault.

Created attachment 1113955 [details]
Patch which fixes this issue

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-0831.html