perl-modperl mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jie Gao <J....@sydney.edu.au>
Subject Re: New segfault with 2.4.20 with mod_perl
Date Sun, 29 May 2016 06:02:17 GMT
Hi All

I wonder if anybody is looking at this issue. At the moment, the build cores even at the end
of generating a Makefile.

If not, I would like to get my hands dirty in an attmpt to get the ball rolling. Any help
on how to get a handle on the "ip comparisons" recommended by W. Rowe Jr would be much appreciated.

Regards,


Jie


* William A Rowe Jr <wrowe@rowe-clan.net> wrote:

> Date: Thu, 19 May 2016 11:23:33 -0500
> From: William A Rowe Jr <wrowe@rowe-clan.net>
> To: httpd <dev@httpd.apache.org>, modperl@perl.apache.org
> Subject: Re: New segfault with 2.4.20 with mod_perl
> 
> Re-sending to include the correct perl.a.o dev list.
> 
> On Thu, Apr 14, 2016 at 1:25 PM, William A Rowe Jr <wrowe@rowe-clan.net>
> wrote:
> 
> > The defect appears to be in t/protocol/TestProtocol/pseudo_http.pm...
> >
> > First, the handler is registered using
> >
> >   PerlProcessConnectionHandler TestProtocol::pseudo_http
> >
> > so its activities are outside of the request handling phase.
> >
> > Note that this logic has been broken, for a long time;
> >
> >           <IfVersion > 2.4.1>
> >               <IfModule mod_access_compat.c>
> >                   Order Deny,Allow
> >                   Allow from @servername@
> >               </IfModule>
> >           </IfVersion>
> >
> > Where @servername@ is a hostname, this module defect was
> > identified in version 2.4.20 when we began using the per-req
> > hostname in comparison (based on r->useragent_addr, which
> > is obviously is null during part of the read_request phase).
> >
> > But this module using mod_access_compat during the connection
> > phase has been broken for much longer, since Allow from {ip-addr}
> > would already have failed since 2.4.1 was released, due to the
> > same null r->useragent_addr.
> >
> > Effectively, mod_access_compat.c never supported per-connection
> > IP addresses since it was added.  The fact that it supported
> > per-connection hostname comparison was a quirk, and that the
> > pseudo_http tests only looked at hostname and not ip comparisons
> > was an oversight.
> >
> > But the module will fail in other manners if attempting to use
> > http request_rec processing since that record is never fleshed
> > out with the proper read/post_read request hook phases.
> >
> > My thought is to simply decouple access_compat from this
> > module test... opinions?
> >
> > See also; https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=820824;msg=5
> >
> >
> > On Thu, Apr 14, 2016 at 11:55 AM, William A Rowe Jr <wrowe@rowe-clan.net>
> > wrote:
> >
> >> We can be more vigilant about unexpectedly null values, however...
> >>
> >> how are you running request processing in the connection callback
> >> of mod_perl?  That makes no sense, and probably signals a deeper
> >> logic error.
> >>
> >> The access checker is configured per-dir, so until the request rec
> >> is completely initialized during read_request, this doesn't make
> >> much sense to me (full backtrace .. including frames #6-#10, for
> >> those who are curious...)
> >>
> >> Either the callback list registered for modperl_callback_connection,
> >> or the Perl_runops_standard, or the Perl_pp_entersub invoking the
> >> run_access_checker hook seem the most suspect here.
> >>
> >> #0  apr_getnameinfo (hostname=hostname@entry=0x7fd4461ee368, sockaddr=0x0, flags=flags@entry=0)
> >>     at /tmp/buildd/apr-1.5.2/network_io/unix/sockaddr.c:663
> >> #1  0x000055feaf0f513a in ap_get_useragent_host (r=r@entry=0x7fd4461ee0a0, type=type@entry=3,
> >>     str_is_ip=str_is_ip@entry=0x7fd44740c9c4) at core.c:990
> >> #2  0x00007fd4519d7212 in find_allowdeny (r=r@entry=0x7fd4461ee0a0, method=method@entry=0,
a=<optimized out>,
> >>     a=<optimized out>) at mod_access_compat.c:279
> >> #3  0x00007fd4519d74b2 in check_dir_access (r=0x7fd4461ee0a0) at mod_access_compat.c:332
> >> #4  0x000055feaf0f8f30 in ap_run_access_checker (r=r@entry=0x7fd4461ee0a0) at
request.c:87
> >> #5  0x00007fd448a6f7dd in XS_Apache2__RequestRec_run_access_checker (my_perl=0x55feb2964a20,
cv=<optimized out>)
> >>     at HookRun.c:235
> >> #6  0x00007fd44f5f7e6a in Perl_pp_entersub () from /usr/lib/x86_64-linux-gnu/libperl.so.5.22
> >> #7  0x00007fd44f5f0ca6 in Perl_runops_standard () from /usr/lib/x86_64-linux-gnu/libperl.so.5.22
> >> #8  0x00007fd44f575f06 in Perl_call_sv () from /usr/lib/x86_64-linux-gnu/libperl.so.5.22
> >> #9  0x00007fd44f91ec28 in modperl_callback (my_perl=my_perl@entry=0x55feb2964a20,
handler=0x7fd4461f2750,
> >>     p=p@entry=0x7fd4461f2028, r=r@entry=0x0, s=s@entry=0x7fd453ddc628, args=0x55feb3beebd0)
> >>     at modperl_callback.c:100
> >> #10 0x00007fd44f91f576 in modperl_callback_run_handlers (idx=0, type=type@entry=1,
r=r@entry=0x0,
> >>     c=<optimized out>, s=0x7fd453ddc628, pconf=pconf@entry=0x0, plog=0x0,
ptemp=0x0, run_mode=MP_HOOK_RUN_FIRST)
> >>     at modperl_callback.c:236
> >> #11 0x00007fd44f91fd4f in modperl_callback_connection (idx=<optimized out>,
c=<optimized out>,
> >>     run_mode=<optimized out>) at modperl_callback.c:359
> >> #12 0x000055feaf10cdf0 in ap_run_process_connection (c=c@entry=0x7fd4461f22b8)
at connection.c:42
> >> #13 0x000055feaf10d340 in ap_process_connection (c=c@entry=0x7fd4461f22b8, csd=csd@entry=0x7fd4461f20a0)
> >>     at connection.c:226
> >> #14 0x00007fd4523f3e6b in process_socket (bucket_alloc=0x7fd4461f0028, my_thread_num=1,
my_child_num=0,
> >>     sock=0x7fd4461f20a0, p=0x7fd4461f2028, thd=0x7fd453eb27a0) at worker.c:631
> >> #15 worker_thread (thd=0x7fd453eb27a0, dummy=<optimized out>) at worker.c:990
> >> #16 0x00007fd453418454 in start_thread (arg=0x7fd44740d700) at pthread_create.c:334
> >> #17 0x00007fd453155ecd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109
> >>
> >>
> >> Before we chase down a potential non-defect in httpd, any thoughts
> >> on the underlying modperl or script logic?
> >>
> >>
> >> On Thu, Apr 14, 2016 at 1:44 AM, Takashi Sato <takashi@tks.st> wrote:
> >>
> >>> r->useragent_addr is assigned on ap_read_request (http_core.c),
> >>> called from ap_process_http_(async_)connection
> >>> called from process_connection hook (APR_HOOK_REALLY_LAST).
> >>>
> >>> The SEGV occured on process_connection hook, maybe before
> >>> ap_process_http_(async_)connection,
> >>>
> >>> #11 0x00007fd44f91fd4f in modperl_callback_connection (idx=<optimized
> >>> out>, c=<optimized out>,
> >>>     run_mode=<optimized out>) at modperl_callback.c:359
> >>> #12 0x000055feaf10cdf0 in ap_run_process_connection
> >>> (c=c@entry=0x7fd4461f22b8) at connection.c:42
> >>> #13 0x000055feaf10d340 in ap_process_connection
> >>> (c=c@entry=0x7fd4461f22b8, csd=csd@entry=0x7fd4461f20a0)
> >>>     at connection.c:226
> >>>
> >>> so r->useragent_addr had not been assigned any value.
> >>>
> >>
> >>
> >

Mime
View raw message