[Bug-wget] [PATCH] wget-1.14 segfaults because of bug in redirect_output() at log.c

[Tomas Hozza]

Hi.

I was reviewing wget Bugs backlog we have in Fedora and found
one older Bug (https://bugzilla.redhat.com/show_bug.cgi?id=913153).

I believe that it is possible that under some specific circumstances
there is a fprintf call (at log.c:873) with uninitialized char pointer.

Unfortunately I was unable to reproduce the issue and also the reporter
is not responding. But I think the change I propose is really straight
forward and obvious.

The truncated backtrace (in our Fedora package) was:
Thread no. 1 (10 frames)
 #0 _IO_vfprintf_internal at vfprintf.c:1615
 #1 buffered_vfprintf at vfprintf.c:2299
 #2 _IO_vfprintf_internal at vfprintf.c:1269
 #3 ___fprintf_chk at fprintf_chk.c:36
 #4 fprintf at /usr/include/bits/stdio2.h:97
 #5 redirect_output at log.c:873
 #6 check_redirect_output at log.c:889
 #7 logprintf at log.c:533
 #8 connect_to_ip at connect.c:371
 #9 connect_to_host at connect.c:404

My proposed patch is attached.


Regards,

Tomas Hozza

0001-Fix-using-deadcode-and-possible-use-of-NULL-pointer.patch
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