Wireshark · Wireshark-commits: [Wireshark-commits] master 48a6ea0: ssh: don't crash when computing hash.

[Wireshark code review <code-review-do-not-reply@xxxxxxxxxxxxx>]

URL: https://code.wireshark.org/review/gitweb?p=wireshark.git;a=commit;h=48a6ea0e05a7637da1dfb6e6acefd64ae0349de5
Submitter: "Guy Harris <gharris@xxxxxxxxx>"
Changed: branch: master
Repository: wireshark

Commits:

48a6ea0 by Guy Harris (gharris@xxxxxxxxx):

    ssh: don't crash when computing hash.
    
    Apparently, it's possile for ssh_keylog_compute_hash() to be called with
    a struct ssh_flow_data structure with a null kex_e; if it is, give up on
    computing the hash before we try dereferencing global_data->kex_e.
    
    See, for example, the capture at
    
    https://wiki.wireshark.org/SampleCaptures?action=AttachFile&do=get&target=Example1.pcap
    
    which crashed if I ran a TShark, built from the tip of the master branch::
    
    TShark (Wireshark) 3.3.0 (v3.3.0rc0-1806-g79e43ef98d59)
    
    Copyright 1998-2020 Gerald Combs <gerald@xxxxxxxxxxxxx> and
    contributors.  License GPLv2+: GNU GPL version 2 or later
    <https://www.gnu.org/licenses/gpl-2.0.html> This is free software; see
    the source for copying conditions.  There is NO warranty; not even for
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    
    Compiled (64-bit) with libpcap (including remote capture support),
    without POSIX capabilities, with GLib 2.37.6, with zlib 1.2.11, with SMI
    0.4.8, with c-ares 1.15.0, with Lua 5.2.4, with GnuTLS 3.4.17, with
    Gcrypt 1.7.7, with MIT Kerberos, with MaxMind DB resolver, with nghttp2
    1.39.2, with brotli, with LZ4, with Zstandard, with Snappy, with libxml2
    2.9.9.
    
    Running on Mac OS X 10.15.6, build 19G73 (Darwin 19.6.0), with Intel(R)
    Core(TM) i9-9980HK CPU @ 2.40GHz (with SSE4.2), with 65536 MB of
    physical memory, with locale en_US.UTF-8, with libpcap version
    1.10.0-PRE-GIT, with GnuTLS 3.4.17, with Gcrypt 1.7.7, with brotli
    1.0.7, with zlib 1.2.11, binary plugins supported (0 loaded).
    
    Built using clang 4.2.1 Compatible Apple LLVM 11.0.3 (clang-1103.0.32.62).
    
    with "tshark -n -V -r Example1.pcap".
    
    Change-Id: Icc534b488e5b486597162e54c725afb54ad61c05
    Reviewed-on: https://code.wireshark.org/review/38113
    Petri-Dish: Guy Harris <gharris@xxxxxxxxx>
    Tested-by: Petri Dish Buildbot
    Reviewed-by: Guy Harris <gharris@xxxxxxxxx>
    

Actions performed:

    from  9b07412   Qt: Add a packet diagram view.
     add  48a6ea0   ssh: don't crash when computing hash.


Summary of changes:
 epan/dissectors/packet-ssh.c | 4 ++++
 1 file changed, 4 insertions(+)