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From: Dominick Grift <dominick.grift@defensec.nl>
To: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Aaron Goidel <acgoide@tycho.nsa.gov>,
	paul@paul-moore.com, selinux@vger.kernel.org
Subject: Re: [PATCH] selinux-testsuite: add tests for fsnotify
Date: Tue, 10 Sep 2019 18:32:36 +0200
Message-ID: <20190910163236.GC1058184@brutus.lan> (raw)
In-Reply-To: <fff646bf-0911-fc5a-9a9c-79f4d5c30eae@tycho.nsa.gov>

On Tue, Sep 10, 2019 at 12:25:44PM -0400, Stephen Smalley wrote:
> On 9/10/19 11:22 AM, Dominick Grift wrote:
> > On Tue, Sep 10, 2019 at 11:02:16AM -0400, Stephen Smalley wrote:
> > > On 9/10/19 10:59 AM, Stephen Smalley wrote:
> > > > On 9/10/19 10:54 AM, Stephen Smalley wrote:
> > > > > On 9/10/19 10:40 AM, Stephen Smalley wrote:
> > > > > > On 9/10/19 10:15 AM, Dominick Grift wrote:
> > > > > > > On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote:
> > > > > > > > On 9/10/19 1:59 AM, Dominick Grift wrote:
> > > > > > > > > On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote:
> > > > > > > > > > Added a suite to test permissions for setting
> > > > > > > > > > inotify and fanotify watches
> > > > > > > > > > on filesystem objects. Tests watch,
> > > > > > > > > > watch_with_perm, and watch_reads permissions.
> > > > > > > > > 
> > > > > > > > > Ive also "tested" the fsnotify patch. And my tests
> > > > > > > > > indicate that this might cause issues:
> > > > > > > > > 
> > > > > > > > > I added the access vectors to my policy, but on
> > > > > > > > > older systems (debian 10) cron fails to start
> > > > > > > > > cron needs the "entrypoint" permission on
> > > > > > > > > /etc/crontab but it looks like appending the "watch"
> > > > > > > > > access vectors to common-file disrupted the ordering
> > > > > > > > > The result is that now i have to allow cron to
> > > > > > > > > "watch_read" /etc/crontab even though the neither
> > > > > > > > > kernel nor selinux user space are aware of the
> > > > > > > > > fsnotify access vectors
> > > > > > > > > It seems the cron selinux code got confused and now
> > > > > > > > > thinks watch_read is entrypoint (its using selinux
> > > > > > > > > code to determine whether it can manually transition
> > > > > > > > > to cronjob domains on crontabs)
> > > > > > > > > 
> > > > > > > > > I am hoping this issue with resolve itself on
> > > > > > > > > systems with kernels and user spaces that suppose
> > > > > > > > > fsnotify.
> > > > > > > > > However unless i am overlooking something this is
> > > > > > > > > still likely to disrupt compatibility
> > > > > > > > 
> > > > > > > > So, IIUC, the issue is that:
> > > > > > > > a) older cron was directly using the fixed
> > > > > > > > FILE__ENTRYPOINT definition from
> > > > > > > > libselinux in a security_compute_av() call rather than
> > > > > > > > dynamically looking
> > > > > > > > up entrypoint permission,
> > > > > > > > b) the value of the file entrypoint permission in policy
> > > > > > > > has changed because
> > > > > > > > you updated your policy and chose to place the watch*
> > > > > > > > permissions in the
> > > > > > > > common file definition to match the kernel.
> > > > > > > > 
> > > > > > > > Note that you could have instead sprinkled copies of the
> > > > > > > > watch* permissions
> > > > > > > > across all of the individual file/dir/*_file classes and
> > > > > > > > placed them at the
> > > > > > > > end of the classes if you wanted to avoid this
> > > > > > > > compatibility issue. The
> > > > > > > > policy and kernel definitions no longer need to be
> > > > > > > > identical; the kernel
> > > > > > > > will dynamically map between them for its own permission checks.
> > > > > > > > 
> > > > > > > > Also, this should have already been broken for you when
> > > > > > > > map permission was
> > > > > > > > added, which would have shown up as execute_no_trans
> > > > > > > > being checked instead
> > > > > > > > of entrypoint.  This was already filed as a bug on cron
> > > > > > > > in debian here:
> > > > > > > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716
> > > > > > > > 
> > > > > > > > So, wrt compatibility, IIUC:
> > > > > > > > - the kernel change does not break compatibility for old policy + old
> > > > > > > > userspace,
> > > > > > > > - new policy can choose to add the new permissions in a
> > > > > > > > backward-compatible
> > > > > > > > manner if desired, although refpolicy has already chosen
> > > > > > > > not to do this for
> > > > > > > > map permission,
> > > > > > > > - the offending code in cron produces build warnings
> > > > > > > > that were introduced in
> > > > > > > > 2014 in libselinux to update their code to use the dynamic class/perm
> > > > > > > > mapping support, which would resolve the issue.
> > > > > > > 
> > > > > > > this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d
> > > > > > > 
> > > > > > > 
> > > > > > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x
> > > > > > > --common common_file
> > > > > > > 
> > > > > > > Commons: 1
> > > > > > >      common common_file
> > > > > > > {
> > > > > > >           append
> > > > > > >           lock
> > > > > > >           mounton
> > > > > > >           unlink
> > > > > > >           read
> > > > > > >           create
> > > > > > >           quotaon
> > > > > > >           execute
> > > > > > >           setattr
> > > > > > >           map
> > > > > > >           relabelto
> > > > > > >           rename
> > > > > > >           link
> > > > > > >           ioctl
> > > > > > >           getattr
> > > > > > >           relabelfrom
> > > > > > > }
> > > > > > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile
> > > > > > > 
> > > > > > > Classes: 1
> > > > > > >      class file
> > > > > > > inherits common_file
> > > > > > > {
> > > > > > >           execmod
> > > > > > >           watch
> > > > > > >           write
> > > > > > >           watch_reads
> > > > > > >           execute_no_trans
> > > > > > >           watch_mount
> > > > > > >           watch_with_perm
> > > > > > >           open
> > > > > > >           watch_sb
> > > > > > >           audit_access
> > > > > > >           entrypoint
> > > > > > > }
> > > > > > 
> > > > > > If you want to preserve compatibility with userspace using fixed
> > > > > > definitions of FILE__ENTRYPOINT, then you have to insert any new
> > > > > > file permissions after the current entrypoint permission in the
> > > > > > class file. So watch and friends have to go after it, not before
> > > > > > it.
> > > > > > 
> > > > > > Also, since the kernel always uses FILE__WATCH* in the check
> > > > > > code rather than distinguishing by class, the watch* permissions
> > > > > > need to be at the same offset in all of the file classes.  The
> > > > > > same is true of the other file permissions.  It looks like you
> > > > > > may have other permissions out of sync across the file classes
> > > > > > e.g. execmod, open, audit_access, that need to be aligned or the
> > > > > > kernel could check the wrong permission.
> > > > > 
> > > > > Sorry, the last para isn't correct - it should get mapped correctly
> > > > > per class.  But you do need to add the permissions after entrypoint
> > > > > in the file class to avoid displacing its value.
> > > > 
> > > > Also, it looks like your file class permission order differs in other
> > > > incompatible ways. If you want it to be compatible with the deprecated
> > > > libselinux headers, the requisite order would be:
> > > > class file
> > > > inherits common_file
> > > > {
> > > >       execute_no_trans
> > > >       entrypoint
> > > >       execmod
> > > >       open
> > > >       audit_access
> > > >       map
> > > 
> > > Sorry, insert watch* permissions here.
> > 
> > I applied brute force:
> > 
> > the map permission can be part of common_file just fine.
> > the audit_access av (which was clearly introduced after entrypoint can precede entrypoint just fine.
> > 
> > The problem is the prescence of the fsnotify access vector in general. Moving them out of common_file and after entrypoint does not make a difference.
> > As soon as I remove the fsnotify av's things start to work.
> > 
> > In other words. besides the precensce of the fsnotify access vectors everything (seemingly) is in order
> > Now for me the question remains: will this issue automatically resolve itself as soon as userspace and kernel support the fsnotify av
> 
> That doesn't make any sense to me.  Sounds like a bug somewhere. Anything
> that changes the permission bit value in the policy for FILE__ENTRYPOINT is
> going to break legacy crond that is using the hardcoded value from the
> deprecated libselinux headers.  So adding permissions at the end of the file
> class should be fine.  Adding or removing to/from common file should break.
> I can't explain the behavior you are seeing.

It does not make sense to me either, but i believe it when i see it.
Ive tried several times and just removing the fsnotify access vectors make it work. Whether i append them to common_file or whether i append them to the individual classes does not make a difference.

BTW: this fixes it for me: https://lore.kernel.org/selinux/d706a78c-d6d0-13bb-c9af-7ec4365b9b44@debian.org/T/#u

> 
> > > 
> > > > }
> > > > 
> > > > > 
> > > > > > 
> > > > > > > 
> > > > > > > > 
> > > > > > > > > 
> > > > > > > > > > 
> > > > > > > > > > Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov>
> > > > > > > > > > ---
> > > > > > > > > >     policy/Makefile              |   4 ++
> > > > > > > > > >     policy/test_notify.te        |  74 ++++++++++++++++++++++++
> > > > > > > > > >     tests/Makefile               |   4 ++
> > > > > > > > > >     tests/notify/Makefile        |   5 ++
> > > > > > > > > >     tests/notify/test            | 101
> > > > > > > > > > +++++++++++++++++++++++++++++++++
> > > > > > > > > >     tests/notify/test_fanotify.c | 105
> > > > > > > > > > +++++++++++++++++++++++++++++++++++
> > > > > > > > > >     tests/notify/test_inotify.c  |  43 ++++++++++++++
> > > > > > > > > >     7 files changed, 336 insertions(+)
> > > > > > > > > >     create mode 100644 policy/test_notify.te
> > > > > > > > > >     create mode 100644 tests/notify/Makefile
> > > > > > > > > >     create mode 100755 tests/notify/test
> > > > > > > > > >     create mode 100644 tests/notify/test_fanotify.c
> > > > > > > > > >     create mode 100644 tests/notify/test_inotify.c
> > > > > > > > > > 
> > > > > > > > > > diff --git a/policy/Makefile b/policy/Makefile
> > > > > > > > > > index 305b572..65f88c5 100644
> > > > > > > > > > --- a/policy/Makefile
> > > > > > > > > > +++ b/policy/Makefile
> > > > > > > > > > @@ -71,6 +71,10 @@ ifeq ($(shell grep -q
> > > > > > > > > > corenet_sctp_bind_all_nodes
> > > > > > > > > > $(POLDEV)/include/kernel/coren
> > > > > > > > > >     TARGETS += test_sctp.te
> > > > > > > > > >     endif
> > > > > > > > > > +ifeq ($(shell grep -q all_file_perms.*watch
> > > > > > > > > > $(POLDEV)/include/support/all_perms.spt && echo
> > > > > > > > > > true),true)
> > > > > > > > > > +TARGETS+=test_notify.te
> > > > > > > > > > +endif
> > > > > > > > > > +
> > > > > > > > > >     ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6))
> > > > > > > > > >     TARGETS:=$(filter-out test_overlayfs.te
> > > > > > > > > > test_mqueue.te, $(TARGETS))
> > > > > > > > > >     endif
> > > > > > > > > > diff --git a/policy/test_notify.te b/policy/test_notify.te
> > > > > > > > > > new file mode 100644
> > > > > > > > > > index 0000000..8ba6f1a
> > > > > > > > > > --- /dev/null
> > > > > > > > > > +++ b/policy/test_notify.te
> > > > > > > > > > @@ -0,0 +1,74 @@
> > > > > > > > > > +####################################################
> > > > > > > > > > +# Policy for testing inoftify and fanotify watches #
> > > > > > > > > > +####################################################
> > > > > > > > > > +
> > > > > > > > > > +attribute test_notify_domain;
> > > > > > > > > > +
> > > > > > > > > > +# Type for the file on which we want to set a watch
> > > > > > > > > > +type test_notify_file_t;
> > > > > > > > > > +files_type(test_notify_file_t);
> > > > > > > > > > +
> > > > > > > > > > +# Domain for the process which CAN set a non-permission watch
> > > > > > > > > > +type test_watch_t;
> > > > > > > > > > +domain_type(test_watch_t);
> > > > > > > > > > +unconfined_runs_test(test_watch_t);
> > > > > > > > > > +
> > > > > > > > > > +typeattribute test_watch_t test_notify_domain;
> > > > > > > > > > +typeattribute test_watch_t testdomain;
> > > > > > > > > > +
> > > > > > > > > > +allow test_notify_domain self:capability sys_admin;
> > > > > > > > > > +
> > > > > > > > > > +allow test_watch_t test_notify_file_t:file {
> > > > > > > > > > read write open watch };
> > > > > > > > > > +
> > > > > > > > > > +# Domain for the process which CAN set a NON-access watch on a file
> > > > > > > > > > +type test_perm_watch_t;
> > > > > > > > > > +domain_type(test_perm_watch_t);
> > > > > > > > > > +unconfined_runs_test(test_perm_watch_t);
> > > > > > > > > > +
> > > > > > > > > > +typeattribute test_perm_watch_t test_notify_domain;
> > > > > > > > > > +typeattribute test_perm_watch_t testdomain;
> > > > > > > > > > +
> > > > > > > > > > +allow test_perm_watch_t test_notify_file_t:file
> > > > > > > > > > { read write open watch watch_with_perm };
> > > > > > > > > > +
> > > > > > > > > > +# Domain which CAN set a NON-perm watch which MAY read accesses
> > > > > > > > > > +type test_read_watch_t;
> > > > > > > > > > +domain_type(test_read_watch_t);
> > > > > > > > > > +unconfined_runs_test(test_read_watch_t);
> > > > > > > > > > +
> > > > > > > > > > +typeattribute test_read_watch_t test_notify_domain;
> > > > > > > > > > +typeattribute test_read_watch_t testdomain;
> > > > > > > > > > +
> > > > > > > > > > +allow test_read_watch_t test_notify_file_t:file
> > > > > > > > > > { read write open watch watch_reads };
> > > > > > > > > > +
> > > > > > > > > > +# Domain which CAN set any watch which CAN read accesses
> > > > > > > > > > +type test_perm_read_watch_t;
> > > > > > > > > > +domain_type(test_perm_read_watch_t);
> > > > > > > > > > +unconfined_runs_test(test_perm_read_watch_t);
> > > > > > > > > > +
> > > > > > > > > > +typeattribute test_perm_read_watch_t test_notify_domain;
> > > > > > > > > > +typeattribute test_perm_read_watch_t testdomain;
> > > > > > > > > > +
> > > > > > > > > > +allow test_perm_read_watch_t
> > > > > > > > > > test_notify_file_t:file { read write open watch
> > > > > > > > > > watch_with_perm watch_reads };
> > > > > > > > > > +
> > > > > > > > > > +# Domain which CANNOT set any watches
> > > > > > > > > > +type test_no_watch_t;
> > > > > > > > > > +domain_type(test_no_watch_t);
> > > > > > > > > > +unconfined_runs_test(test_no_watch_t);
> > > > > > > > > > +
> > > > > > > > > > +typeattribute test_no_watch_t test_notify_domain;
> > > > > > > > > > +typeattribute test_no_watch_t testdomain;
> > > > > > > > > > +
> > > > > > > > > > +allow test_no_watch_t test_notify_file_t:file { read write open };
> > > > > > > > > > +
> > > > > > > > > > +# Domain which has no write access but can watch
> > > > > > > > > > +type test_rdonly_t;
> > > > > > > > > > +domain_type(test_rdonly_t);
> > > > > > > > > > +unconfined_runs_test(test_rdonly_t);
> > > > > > > > > > +
> > > > > > > > > > +typeattribute test_rdonly_t test_notify_domain;
> > > > > > > > > > +typeattribute test_rdonly_t testdomain;
> > > > > > > > > > +
> > > > > > > > > > +allow test_rdonly_t test_notify_file_t:file { read open watch };
> > > > > > > > > > +
> > > > > > > > > > +miscfiles_domain_entry_test_files(test_notify_domain);
> > > > > > > > > > +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain);
> > > > > > > > > > diff --git a/tests/Makefile b/tests/Makefile
> > > > > > > > > > index 63aa325..b99c96e 100644
> > > > > > > > > > --- a/tests/Makefile
> > > > > > > > > > +++ b/tests/Makefile
> > > > > > > > > > @@ -50,6 +50,10 @@ ifeq ($(shell grep
> > > > > > > > > > "^SELINUX_INFINIBAND_PKEY_TEST="
> > > > > > > > > > infiniband_pkey/ibpkey_test.
> > > > > > > > > >     SUBDIRS += infiniband_pkey
> > > > > > > > > >     endif
> > > > > > > > > > +ifeq ($(shell grep -q all_file_perms.*watch
> > > > > > > > > > $(POLDEV)/include/support/all_perms.spt && echo
> > > > > > > > > > true),true)
> > > > > > > > > > +SUBDIRS+=notify
> > > > > > > > > > +endif
> > > > > > > > > > +
> > > > > > > > > >     ifeq ($(DISTRO),RHEL4)
> > > > > > > > > >         SUBDIRS:=$(filter-out bounds dyntrace
> > > > > > > > > > dyntrans inet_socket mmap nnp_nosuid overlay
> > > > > > > > > > unix_socket, $(SUBDIRS))
> > > > > > > > > >     endif
> > > > > > > > > > diff --git a/tests/notify/Makefile b/tests/notify/Makefile
> > > > > > > > > > new file mode 100644
> > > > > > > > > > index 0000000..78c4b3b
> > > > > > > > > > --- /dev/null
> > > > > > > > > > +++ b/tests/notify/Makefile
> > > > > > > > > > @@ -0,0 +1,5 @@
> > > > > > > > > > +TARGETS=test_inotify test_fanotify
> > > > > > > > > > +
> > > > > > > > > > +all: $(TARGETS)
> > > > > > > > > > +clean:
> > > > > > > > > > +    rm -f $(TARGETS)
> > > > > > > > > > diff --git a/tests/notify/test b/tests/notify/test
> > > > > > > > > > new file mode 100755
> > > > > > > > > > index 0000000..21f03de
> > > > > > > > > > --- /dev/null
> > > > > > > > > > +++ b/tests/notify/test
> > > > > > > > > > @@ -0,0 +1,101 @@
> > > > > > > > > > +#!/usr/bin/perl
> > > > > > > > > > +
> > > > > > > > > > +use Test;
> > > > > > > > > > +BEGIN { plan tests => 14 }    # number of tests to run
> > > > > > > > > > +
> > > > > > > > > > +# help the test script locate itself
> > > > > > > > > > +$basedir = $0;
> > > > > > > > > > +$basedir =~ s|(.*)/[^/]*|$1|;
> > > > > > > > > > +
> > > > > > > > > > +# Get rid of a testfile from last run if it's there (just in case)
> > > > > > > > > > +system("rm -f $basedir/watch_me");
> > > > > > > > > > +
> > > > > > > > > > +# Create a new test file
> > > > > > > > > > +system("touch $basedir/watch_me");
> > > > > > > > > > +system("chcon -t test_notify_file_t $basedir/watch_me");
> > > > > > > > > > +
> > > > > > > > > > +## TESTS
> > > > > > > > > > +
> > > > > > > > > > +## TEST BASIC WATCH PERMISSION
> > > > > > > > > > +# Should be able to set inotify watch
> > > > > > > > > > +$exit_val =
> > > > > > > > > > +  system("runcon -t test_watch_t
> > > > > > > > > > $basedir/test_inotify $basedir/watch_me 2>&1");
> > > > > > > > > > +ok( $exit_val, 0 );
> > > > > > > > > > +
> > > > > > > > > > +# Should be able to set non-permissions based fanotify watch
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +    "runcon -t test_watch_t
> > > > > > > > > > $basedir/test_fanotify $basedir/watch_me 2>&1");
> > > > > > > > > > +ok( $exit_val, 0 );
> > > > > > > > > > +
> > > > > > > > > > +# Should NOT be able to set permission based fanotify watch
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +    "runcon -t test_watch_t
> > > > > > > > > > $basedir/test_fanotify -p $basedir/watch_me
> > > > > > > > > > 2>&1");
> > > > > > > > > > +ok($exit_val);    # this should fail
> > > > > > > > > > +
> > > > > > > > > > +# Should NOT be able to set read based fanotify watch
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +    "runcon -t test_watch_t
> > > > > > > > > > $basedir/test_fanotify -r $basedir/watch_me
> > > > > > > > > > 2>&1");
> > > > > > > > > > +ok($exit_val);    # this should fail
> > > > > > > > > > +
> > > > > > > > > > +# Should NOT be able to set read based inotify watch
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +    "runcon -t test_watch_t
> > > > > > > > > > $basedir/test_inotify -r $basedir/watch_me
> > > > > > > > > > 2>&1");
> > > > > > > > > > +ok($exit_val);    # this should fail
> > > > > > > > > > +
> > > > > > > > > > +## TEST PERM WATCH
> > > > > > > > > > +# Should be able to set permission based fanotify watch
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +"runcon -t test_perm_watch_t
> > > > > > > > > > $basedir/test_fanotify -p $basedir/watch_me
> > > > > > > > > > 2>&1"
> > > > > > > > > > +);
> > > > > > > > > > +ok( $exit_val, 0 );
> > > > > > > > > > +
> > > > > > > > > > +# Should NOT be able to set watch of accesses
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +"runcon -t test_perm_watch_t
> > > > > > > > > > $basedir/test_fanotify -r $basedir/watch_me
> > > > > > > > > > 2>&1"
> > > > > > > > > > +);
> > > > > > > > > > +ok($exit_val);    # this should fail
> > > > > > > > > > +
> > > > > > > > > > +## TEST READ NO PERM WATCH PERMSISSIONS
> > > > > > > > > > +# Should NOT be able to set read and perm watch
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +"runcon -t test_read_watch_t
> > > > > > > > > > $basedir/test_fanotify -p -r $basedir/watch_me
> > > > > > > > > > 2>&1"
> > > > > > > > > > +);
> > > > > > > > > > +ok($exit_val);    # should fail
> > > > > > > > > > +
> > > > > > > > > > +# Should be able to set read inotify watch
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +"runcon -t test_read_watch_t
> > > > > > > > > > $basedir/test_inotify -r $basedir/watch_me 2>&1"
> > > > > > > > > > +);
> > > > > > > > > > +ok( $exit_val, 0 );
> > > > > > > > > > +
> > > > > > > > > > +## TEST READ WITH PERM WATCH PERMSISSIONS
> > > > > > > > > > +# Should be able to set read and perm watch
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +"runcon -t test_perm_read_watch_t
> > > > > > > > > > $basedir/test_fanotify -p -r $basedir/watch_me
> > > > > > > > > > 2>&1"
> > > > > > > > > > +);
> > > > > > > > > > +ok( $exit_val, 0 );
> > > > > > > > > > +
> > > > > > > > > > +## TEST NO WATCH PERMSISSIONS
> > > > > > > > > > +# Should NOT be able to set inotify watch
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +    "runcon -t test_no_watch_t
> > > > > > > > > > $basedir/test_inotify $basedir/watch_me 2>&1");
> > > > > > > > > > +ok($exit_val);    # this should fail
> > > > > > > > > > +
> > > > > > > > > > +# Should NOT be able to set any fanotify watch
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +    "runcon -t test_no_watch_t
> > > > > > > > > > $basedir/test_fanotify $basedir/watch_me 2>&1");
> > > > > > > > > > +ok($exit_val);    # this should fail
> > > > > > > > > > +
> > > > > > > > > > +## TEST READ ONLY
> > > > > > > > > > +# Should NOT be able to get read-write descriptor
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +    "runcon -t test_rdonly_t
> > > > > > > > > > $basedir/test_fanotify -l $basedir/watch_me
> > > > > > > > > > 2>&1");
> > > > > > > > > > +ok($exit_val);    # this should fail
> > > > > > > > > > +
> > > > > > > > > > +# Should be able to get read-write descriptor
> > > > > > > > > > +$exit_val = system(
> > > > > > > > > > +    "runcon -t test_watch_t
> > > > > > > > > > $basedir/test_fanotify -l $basedir/watch_me
> > > > > > > > > > 2>&1");
> > > > > > > > > > +ok( $exit_val, 0 );
> > > > > > > > > > +
> > > > > > > > > > +# Clean up test file
> > > > > > > > > > +system("rm -f $basedir/watch_me");
> > > > > > > > > > diff --git a/tests/notify/test_fanotify.c
> > > > > > > > > > b/tests/notify/test_fanotify.c
> > > > > > > > > > new file mode 100644
> > > > > > > > > > index 0000000..fff773f
> > > > > > > > > > --- /dev/null
> > > > > > > > > > +++ b/tests/notify/test_fanotify.c
> > > > > > > > > > @@ -0,0 +1,105 @@
> > > > > > > > > > +#define _GNU_SOURCE 1
> > > > > > > > > > +
> > > > > > > > > > +#include <stdio.h>
> > > > > > > > > > +#include <stdlib.h>
> > > > > > > > > > +
> > > > > > > > > > +#include <getopt.h>
> > > > > > > > > > +
> > > > > > > > > > +#include <fcntl.h>
> > > > > > > > > > +#include <poll.h>
> > > > > > > > > > +#include <sys/fanotify.h>
> > > > > > > > > > +#include <unistd.h>
> > > > > > > > > > +
> > > > > > > > > > +void printUsage()
> > > > > > > > > > +{
> > > > > > > > > > +    fprintf(stderr, "Usage: test_fanotify [-p]
> > > > > > > > > > [-r] [-l] file_name\n");
> > > > > > > > > > +    exit(1);
> > > > > > > > > > +}
> > > > > > > > > > +
> > > > > > > > > > +int main(int argc, char *argv[])
> > > > > > > > > > +{
> > > > > > > > > > +    if (argc < 2) {
> > > > > > > > > > +        printUsage();
> > > > > > > > > > +    }
> > > > > > > > > > +
> > > > > > > > > > +    int fd, ret, arg;
> > > > > > > > > > +    int mask = FAN_OPEN;  // default mask
> > > > > > > > > > +    int listening = 0;
> > > > > > > > > > +
> > > > > > > > > > +    // the -p flag will test for watch_with_perm
> > > > > > > > > > +    // the mask used at mark will contain FAN_OPEN_PERM
> > > > > > > > > > +    //
> > > > > > > > > > +    // the -r flag will test for watching
> > > > > > > > > > accesses to files for reads
> > > > > > > > > > +    // the mask will contain FAN_ACCESS
> > > > > > > > > > +    while ((arg = getopt(argc, argv, "prl")) != -1) {
> > > > > > > > > > +        switch (arg) {
> > > > > > > > > > +        case 'p':
> > > > > > > > > > +            mask |= FAN_OPEN_PERM;
> > > > > > > > > > +            break;
> > > > > > > > > > +        case 'r':
> > > > > > > > > > +            mask |= FAN_ACCESS;
> > > > > > > > > > +            break;
> > > > > > > > > > +        case 'l':
> > > > > > > > > > +            listening = 1;
> > > > > > > > > > +            break;
> > > > > > > > > > +        default:
> > > > > > > > > > +            printUsage();
> > > > > > > > > > +        }
> > > > > > > > > > +    }
> > > > > > > > > > +
> > > > > > > > > > +    // get file descriptor for new fanotify event queue
> > > > > > > > > > +    fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR);
> > > > > > > > > > +    if (fd < 0) {
> > > > > > > > > > +        perror("fanotify_init:bad file descriptor");
> > > > > > > > > > +        exit(1);
> > > > > > > > > > +    }
> > > > > > > > > > +
> > > > > > > > > > +    // mark a filesystem object and add mark to event queue
> > > > > > > > > > +    // get notifications on file opens, accesses, and closes
> > > > > > > > > > +    // use current working directory as base dir
> > > > > > > > > > +    ret = fanotify_mark(fd, FAN_MARK_ADD, mask,
> > > > > > > > > > AT_FDCWD, argv[optind]);
> > > > > > > > > > +
> > > > > > > > > > +    if (ret < 0) {
> > > > > > > > > > +        perror("test_fanotify:watch denied");
> > > > > > > > > > +        exit(1);
> > > > > > > > > > +    }
> > > > > > > > > > +
> > > > > > > > > > +    // logic to actually listen for an event if
> > > > > > > > > > the -l flag is passed
> > > > > > > > > > +    // this is used to test if an app with
> > > > > > > > > > read-only access can get a read/write
> > > > > > > > > > +    // handle to the watched file
> > > > > > > > > > +    if (listening) {
> > > > > > > > > > +        if (fork() == 0) {  // fork a child
> > > > > > > > > > process to cause an event on the file
> > > > > > > > > > +            FILE *f;
> > > > > > > > > > +
> > > > > > > > > > +            f = fopen(argv[optind], "r");  // open file for reading
> > > > > > > > > > +            fgetc(f);                      // read char from file
> > > > > > > > > > +
> > > > > > > > > > +            fclose(f);
> > > > > > > > > > +        } else {  // logic to watch for events
> > > > > > > > > > and try to access file read/write
> > > > > > > > > > +            struct pollfd fds;
> > > > > > > > > > +            fds.fd = fd;
> > > > > > > > > > +            fds.events = POLLIN;
> > > > > > > > > > +
> > > > > > > > > > +            while (listening) {
> > > > > > > > > > +                int polled = poll(&fds, 1, 1);
> > > > > > > > > > +                if (polled > 0) {
> > > > > > > > > > +                    if (fds.revents & POLLIN) {
> > > > > > > > > > +                        struct fanotify_event_metadata buff[200];
> > > > > > > > > > +
> > > > > > > > > > +                        size_t len = read(fd,
> > > > > > > > > > (void *)&buff, sizeof(buff));
> > > > > > > > > > +                        if (len == -1) {
> > > > > > > > > > +
> > > > > > > > > > perror("test_fanotify:can't open file");
> > > > > > > > > > +                            exit(1);
> > > > > > > > > > +                        } else {
> > > > > > > > > > +                            listening = 0;
> > > > > > > > > > +                            break;
> > > > > > > > > > +                        }
> > > > > > > > > > +                    }
> > > > > > > > > > +                } else if (polled == -1) {
> > > > > > > > > > +                    listening = 0;
> > > > > > > > > > +                }
> > > > > > > > > > +            }
> > > > > > > > > > +        }
> > > > > > > > > > +    }
> > > > > > > > > > +    exit(0);
> > > > > > > > > > +}
> > > > > > > > > > diff --git a/tests/notify/test_inotify.c
> > > > > > > > > > b/tests/notify/test_inotify.c
> > > > > > > > > > new file mode 100644
> > > > > > > > > > index 0000000..17c3565
> > > > > > > > > > --- /dev/null
> > > > > > > > > > +++ b/tests/notify/test_inotify.c
> > > > > > > > > > @@ -0,0 +1,43 @@
> > > > > > > > > > +#include <stdio.h>
> > > > > > > > > > +#include <stdlib.h>
> > > > > > > > > > +#include <sys/inotify.h>
> > > > > > > > > > +#include <getopt.h>
> > > > > > > > > > +
> > > > > > > > > > +int main(int argc, char *argv[])
> > > > > > > > > > +{
> > > > > > > > > > +    if (argc < 2) {
> > > > > > > > > > +        fprintf(stderr, "Usage: test_inotify [-r] file_name\n");
> > > > > > > > > > +        exit(1);
> > > > > > > > > > +    }
> > > > > > > > > > +
> > > > > > > > > > +    int fd, wd, arg;
> > > > > > > > > > +    int mask = IN_MODIFY;
> > > > > > > > > > +
> > > > > > > > > > +    while ((arg = getopt(argc, argv, "pr")) != -1) {
> > > > > > > > > > +        switch (arg) {
> > > > > > > > > > +        case 'r':
> > > > > > > > > > +            mask |= IN_ACCESS;
> > > > > > > > > > +            break;
> > > > > > > > > > +        default:
> > > > > > > > > > +            fprintf(stderr, "Usage:
> > > > > > > > > > test_inotify [-r] file_name\n");
> > > > > > > > > > +            exit(1);
> > > > > > > > > > +        }
> > > > > > > > > > +    }
> > > > > > > > > > +
> > > > > > > > > > +    // get new file descriptor for inotify access
> > > > > > > > > > +    fd = inotify_init();
> > > > > > > > > > +    if (fd < 0) {
> > > > > > > > > > +        perror("inotify_init:bad file descriptor");
> > > > > > > > > > +        exit(1);
> > > > > > > > > > +    }
> > > > > > > > > > +
> > > > > > > > > > +    // set watch on file and get watch
> > > > > > > > > > descriptor for accessing events on it
> > > > > > > > > > +    wd = inotify_add_watch(fd, argv[optind], mask);
> > > > > > > > > > +
> > > > > > > > > > +    if (wd < 0) {
> > > > > > > > > > +        perror("test_inotify:watch denied");
> > > > > > > > > > +        exit(1);
> > > > > > > > > > +    }
> > > > > > > > > > +
> > > > > > > > > > +    exit(0);
> > > > > > > > > > +}
> > > > > > > > > > -- 
> > > > > > > > > > 2.21.0
> > > > > > > > > > 
> > > > > > > > > 
> > > > > > > > 
> > > > > > > 
> > > > > > 
> > > > > 
> > > > 
> > > 
> > 
> 

-- 
Key fingerprint = 5F4D 3CDB D3F8 3652 FBD8 02D5 3B6C 5F1D 2C7B 6B02
https://sks-keyservers.net/pks/lookup?op=get&search=0x3B6C5F1D2C7B6B02
Dominick Grift

  reply index

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-10 13:39 Aaron Goidel
2019-07-10 13:50 ` Aaron Goidel
2019-08-27 17:14 ` Paul Moore
2019-09-16 19:50   ` Stephen Smalley
2019-09-10  5:59 ` Dominick Grift
2019-09-10 12:26   ` Stephen Smalley
2019-09-10 14:15     ` Dominick Grift
2019-09-10 14:36       ` Dominick Grift
2019-09-10 14:40       ` Stephen Smalley
2019-09-10 14:54         ` Stephen Smalley
2019-09-10 14:59           ` Stephen Smalley
2019-09-10 15:02             ` [Non-DoD Source] " Stephen Smalley
2019-09-10 15:22               ` Dominick Grift
2019-09-10 16:25                 ` Stephen Smalley
2019-09-10 16:32                   ` Dominick Grift [this message]
2019-09-10 18:13                     ` Stephen Smalley
2019-09-10 18:20                       ` Dominick Grift
2019-09-10 19:45                         ` Stephen Smalley
2019-09-10 19:55                           ` Stephen Smalley
2019-09-10 20:00                             ` Dominick Grift
2019-08-01 11:35 Aaron Goidel

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