NetBSD Problem Report #51952

From brad.harder@gmail.com  Sun Feb  5 20:50:17 2017
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Message-Id: <CABfrOT-NHSF003PUCKz=21_5QSEKbJzA6j+QnX92ztCiuMhEvQ@mail.gmail.com>
Date: Sun, 5 Feb 2017 12:50:14 -0800
From: bch <brad.harder@gmail.com>
Reply-To:
To: gnats-bugs@netbsd.org
Subject: libpcap fault applying filter to unactivated handle

>Number:         51952
>Category:       lib
>Synopsis:       libpcap will fault if an attempt to apply a filter on non-activated handle occurs.
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Feb 05 20:55:00 +0000 2017
>Closed-Date:    Tue Aug 15 15:51:02 +0000 2017
>Last-Modified:  Tue Aug 15 15:51:02 +0000 2017
>Originator:     bch <brad.harder@gmail.com>
>Release:        NetBSD 7.99.59
>Organization:
	method logic digital
>Environment:
System: NetBSD kamloops 7.99.59 NetBSD 7.99.59 (MODULAR) #51: Sun Feb
5 09:44:00 PST 2017
root@kamloops:/usr/src/sys/arch/amd64/compile/obj/MODULAR amd64
Architecture: x86_64
Machine: amd64
>Description:
libpcap faults if one tries to apply a filter to an unactivated pcap handle.
>How-To-Repeat:
        ...
        char errbuf[PCAP_ERRBUF_SIZE];
        struct bpf_program fp;

        pcap_t *handle = pcap_create("wm0", errbuf);
	pcap_compile(handle, &fp, "port 80", 0, PCAP_NETMASK_UNKNOWN); /* not
yet activated... */
        // segfault in freechunks()
>Fix:

The compiler state "chunks" initialization is short-circuited if
the handle is not activated, but the chunks cleanup is unconditional.
Unconditionally initializing allows cleanup in case of error-state
to happen fault-free.

nb: patch already submitted upstream to the-tcpdump-group.

FIX
===

--- ./external/bsd/libpcap/dist/gencode.old     2017-02-05
12:34:30.181700021 -0800
+++ ./external/bsd/libpcap/dist/gencode.c       2017-02-05
12:35:03.506099929 -0800
@@ -688,13 +688,13 @@
         * If this pcap_t hasn't been activated, it doesn't have a
         * link-layer type, so we can't use it.
         */
+       initchunks(&cstate);
        if (!p->activated) {
                pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
                    "not-yet-activated pcap_t passed to pcap_compile");
                rc = -1;
                goto quit;
        }
-       initchunks(&cstate);
        cstate.no_optimize = 0;
        cstate.ai = NULL;
        cstate.ic.root = NULL;

>Release-Note:

>Audit-Trail:
From: bch <brad.harder@gmail.com>
To: gnats-bugs@netbsd.org
Cc: 
Subject: Re: lib/51952: libpcap fault applying filter to unactivated handle
Date: Sun, 5 Feb 2017 13:24:43 -0800

 This was fixed alternatively upstream by (roughly):

 kamloops# diff -bu ./external/bsd/libpcap/dist/gencode.old
 ./external/bsd/libpcap/dist/gencode.c
 kamloops# diff -bu ./external/bsd/libpcap/dist/gencode.old
 ./external/bsd/libpcap/dist/gencode.c
 --- ./external/bsd/libpcap/dist/gencode.old     2017-02-05
 12:34:30.181700021 -0800
 +++ ./external/bsd/libpcap/dist/gencode.c       2017-02-05
 13:13:35.332722415 -0800
 @@ -691,8 +691,7 @@
         if (!p->activated) {
                 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
                     "not-yet-activated pcap_t passed to pcap_compile");
 -               rc = -1;
 -               goto quit;
 +               return -1;
         }
         initchunks(&cstate);
         cstate.no_optimize = 0;



 ref: https://github.com/the-tcpdump-group/libpcap/commit/ada95c9321eab3793d485ca026cda54afca9d541



 On 2/5/17, gnats-admin@netbsd.org <gnats-admin@netbsd.org> wrote:
 > Thank you very much for your problem report.
 > It has the internal identification `lib/51952'.
 > The individual assigned to look at your
 > report is: lib-bug-people.
 >
 >>Category:       lib
 >>Responsible:    lib-bug-people
 >>Synopsis:       libpcap will fault if an attempt to apply a filter on
 >> non-activated handle occurs.
 >>Arrival-Date:   Sun Feb 05 20:55:00 +0000 2017
 >
 >

From: "Brian Ginsbach" <ginsbach@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/51952 CVS commit: src/external/bsd/libpcap/dist
Date: Sat, 12 Aug 2017 00:43:25 +0000

 Module Name:	src
 Committed By:	ginsbach
 Date:		Sat Aug 12 00:43:25 UTC 2017

 Modified Files:
 	src/external/bsd/libpcap/dist: gencode.c

 Log Message:
 PR lib/51952: Brad Harder: Apply upstream ada959c9

 [From upstream tcpdump]
  In pcap_compile(), first check whether the pcap_t is activated.

  Before we allocate or otherwise set up anything, check whether the
  pcap_t is activated, and set the error message string and return -1 if
  it's not.

  That way, we don't go through the cleanup code in that code path -
  there's nothing to clean up.

  Fixes the issue in GitHub pull request #552.

 XXX: pullup-8


 To generate a diff of this commit:
 cvs rdiff -u -r1.9 -r1.10 src/external/bsd/libpcap/dist/gencode.c

 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.

State-Changed-From-To: open->pending-pullups
State-Changed-By: ginsbach@NetBSD.org
State-Changed-When: Sat, 12 Aug 2017 01:34:02 +0000
State-Changed-Why:
Pullup requested for NetBSD 8.


From: "Soren Jacobsen" <snj@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/51952 CVS commit: [netbsd-8] src/external/bsd/libpcap/dist
Date: Mon, 14 Aug 2017 23:56:35 +0000

 Module Name:	src
 Committed By:	snj
 Date:		Mon Aug 14 23:56:35 UTC 2017

 Modified Files:
 	src/external/bsd/libpcap/dist [netbsd-8]: gencode.c

 Log Message:
 Pull up following revision(s) (requested by ginsbach in ticket #209):
 	external/bsd/libpcap/dist/gencode.c: revision 1.10
 PR lib/51952: Brad Harder: Apply upstream ada959c9
 [From upstream tcpdump]
  In pcap_compile(), first check whether the pcap_t is activated.
  Before we allocate or otherwise set up anything, check whether the
  pcap_t is activated, and set the error message string and return -1 if
  it's not.
  That way, we don't go through the cleanup code in that code path -
  there's nothing to clean up.
  Fixes the issue in GitHub pull request #552.


 To generate a diff of this commit:
 cvs rdiff -u -r1.9 -r1.9.4.1 src/external/bsd/libpcap/dist/gencode.c

 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.

State-Changed-From-To: pending-pullups->closed
State-Changed-By: ginsbach@NetBSD.org
State-Changed-When: Tue, 15 Aug 2017 15:51:02 +0000
State-Changed-Why:
Fixed in current and pulled up to netbsd-8.


>Unformatted:

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