Date:   Fri, 21 Dec 2018 11:34:16 +0100
From:   Dominick Grift <dac.override@gmail.com>
To:     David Sugar <dsugar@tresys.com>
Cc:     "selinux-refpolicy@vger.kernel.org" 
        <selinux-refpolicy@vger.kernel.org>
Subject: Re: [PATCH 2/2] pam_faillock creates files in /run/faillock
Message-ID: <20181221103416.GA4520@brutus.lan>
Mail-Followup-To: David Sugar <dsugar@tresys.com>,
        "selinux-refpolicy@vger.kernel.org" <selinux-refpolicy@vger.kernel.org>
References: <20181221014026.2867-1-dsugar@tresys.com>
 <20181221014026.2867-2-dsugar@tresys.com>
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On Fri, Dec 21, 2018 at 01:41:25AM +0000, David Sugar wrote:
> These are changes needed when pam_fallock created files in /run/faillock
> (which is labeled faillog_t).  sudo and xdm (and probably other domains)
> will create files in this directory for successful and failed logins
> attempts.

The pam stuff has become a bit broken in my view.

We use to use auth_use_pam() for these kinds of things but the interface wa=
s forgotten and not updated properly.

So for example sudo does not even call auth_use_pam() and a lot of stuff wa=
s added directly to the login_pgm domain that should have been added to aut=
h_use_pam() instead.

My opinion is that this belongs in auth_use_pam()


>=20
> type=3DAVC msg=3Daudit(1545153126.899:210): avc:  denied  { search } for =
pid=3D8448 comm=3D"lightdm" name=3D"faillock" dev=3D"tmpfs" ino=3D39318 sco=
ntext=3Dsystem_u:system_r:xdm_t:s0-s0:c0.c1023 tcontext=3Dsystem_u:object_r=
:faillog_t:s0 tclass=3Ddir permissive=3D1
> type=3DAVC msg=3Daudit(1545153131.090:214): avc:  denied  { write } for p=
id=3D8448 comm=3D"lightdm" name=3D"faillock" dev=3D"tmpfs" ino=3D39318 scon=
text=3Dsystem_u:system_r:xdm_t:s0-s0:c0.c1023 tcontext=3Dsystem_u:object_r:=
faillog_t:s0 tclass=3Ddir permissive=3D1
> type=3DAVC msg=3Daudit(1545153131.090:214): avc:  denied  { add_name } fo=
r pid=3D8448 comm=3D"lightdm" name=3D"dsugar" scontext=3Dsystem_u:system_r:=
xdm_t:s0-s0:c0.c1023 tcontext=3Dsystem_u:object_r:faillog_t:s0 tclass=3Ddir=
 permissive=3D1
> type=3DAVC msg=3Daudit(1545153131.090:214): avc:  denied  { create } for =
pid=3D8448 comm=3D"lightdm" name=3D"dsugar" scontext=3Dsystem_u:system_r:xd=
m_t:s0-s0:c0.c1023 tcontext=3Dsystem_u:object_r:faillog_t:s0 tclass=3Dfile =
permissive=3D1
> type=3DAVC msg=3Daudit(1545153131.091:215): avc:  denied  { setattr } for=
 pid=3D8448 comm=3D"lightdm" name=3D"dsugar" dev=3D"tmpfs" ino=3D87599 scon=
text=3Dsystem_u:system_r:xdm_t:s0-s0:c0.c1023 tcontext=3Dsystem_u:object_r:=
faillog_t:s0 tclass=3Dfile permissive=3D1
>=20
> type=3DAVC msg=3Daudit(1545167205.531:626): avc:  denied  { search } for =
pid=3D8264 comm=3D"sudo" name=3D"faillock" dev=3D"tmpfs" ino=3D35405 sconte=
xt=3Dsysadm_u:sysadm_r:cleaner_applyconfig_sudo_t:s0-s0:c0.c1023 tcontext=
=3Dsystem_u:object_r:faillog_t:s0 tclass=3Ddir permissive=3D1
> type=3DAVC msg=3Daudit(1545167205.531:627): avc:  denied  { write } for p=
id=3D8264 comm=3D"sudo" name=3D"faillock" dev=3D"tmpfs" ino=3D35405 scontex=
t=3Dsysadm_u:sysadm_r:cleaner_applyconfig_sudo_t:s0-s0:c0.c1023 tcontext=3D=
system_u:object_r:faillog_t:s0 tclass=3Ddir permissive=3D1
> type=3DAVC msg=3Daudit(1545167205.531:627): avc:  denied  { add_name } fo=
r pid=3D8264 comm=3D"sudo" name=3D"root" scontext=3Dsysadm_u:sysadm_r:clean=
er_applyconfig_sudo_t:s0-s0:c0.c1023 tcontext=3Dsystem_u:object_r:faillog_t=
:s0 tclass=3Ddir permissive=3D1
> type=3DAVC msg=3Daudit(1545167205.531:627): avc:  denied  { create } for =
pid=3D8264 comm=3D"sudo" name=3D"root" scontext=3Dsysadm_u:sysadm_r:cleaner=
_applyconfig_sudo_t:s0-s0:c0.c1023 tcontext=3Dsysadm_u:object_r:faillog_t:s=
0 tclass=3Dfile permissive=3D1
>=20
> Signed-off-by: Dave Sugar <dsugar@tresys.com>
> ---
>  policy/modules/admin/sudo.if       |  1 +
>  policy/modules/services/xserver.te |  1 +
>  policy/modules/system/authlogin.if | 20 ++++++++++++++++++++
>  3 files changed, 22 insertions(+)
>=20
> diff --git a/policy/modules/admin/sudo.if b/policy/modules/admin/sudo.if
> index 7661a2f3..5fab0d04 100644
> --- a/policy/modules/admin/sudo.if
> +++ b/policy/modules/admin/sudo.if
> @@ -113,6 +113,7 @@ template(`sudo_role_template',`
>  	term_relabel_all_ttys($1_sudo_t)
>  	term_relabel_all_ptys($1_sudo_t)
> =20
> +	auth_create_faillog($1_sudo_t)
>  	auth_run_chk_passwd($1_sudo_t, $2)
>  	# sudo stores a token in the pam_pid directory
>  	auth_manage_pam_pid($1_sudo_t)
> diff --git a/policy/modules/services/xserver.te b/policy/modules/services=
/xserver.te
> index 12ad3a87..fd89a95b 100644
> --- a/policy/modules/services/xserver.te
> +++ b/policy/modules/services/xserver.te
> @@ -481,6 +481,7 @@ term_setattr_console(xdm_t)
>  term_use_unallocated_ttys(xdm_t)
>  term_setattr_unallocated_ttys(xdm_t)
> =20
> +auth_create_faillog(xdm_t)
>  auth_domtrans_pam_console(xdm_t)
>  auth_manage_pam_pid(xdm_t)
>  auth_manage_pam_console_data(xdm_t)
> diff --git a/policy/modules/system/authlogin.if b/policy/modules/system/a=
uthlogin.if
> index 7f8c002e..5521aec3 100644
> --- a/policy/modules/system/authlogin.if
> +++ b/policy/modules/system/authlogin.if
> @@ -744,6 +744,26 @@ interface(`auth_append_faillog',`
>  	allow $1 faillog_t:file append_file_perms;
>  ')
> =20
> +########################################
> +## <summary>
> +##	Create fail log lock (in /run/faillock).
> +## </summary>
> +## <param name=3D"domain">
> +##	<summary>
> +##	Domain allowed access.
> +##	</summary>
> +## </param>
> +#
> +interface(`auth_create_faillog',`
> +	gen_require(`
> +		type faillog_t;
> +	')
> +
> +	auth_rw_faillog($1)
> +	create_files_pattern($1, faillog_t, faillog_t)
> +	setattr_files_pattern($1, faillog_t, faillog_t)
> +')
> +
>  ########################################
>  ## <summary>
>  ##	Read and write the login failure log.
> --=20
> 2.19.2
>=20

--=20
Key fingerprint =3D 5F4D 3CDB D3F8 3652 FBD8 02D5 3B6C 5F1D 2C7B 6B02
https://sks-keyservers.net/pks/lookup?op=3Dget&search=3D0x3B6C5F1D2C7B6B02
Dominick Grift

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