"Sugar, David" <dsugar@xxxxxxxxxx> writes:
> The display manager lightdm (and I think gdm) start a dbus binary.
>
> This adds (and uses) new interface dbus_exec to start dbus in the xdm domain.
>
> type=AVC msg=audit(1544626796.378:201): avc: denied { execute } for pid=9973 comm="dbus-launch" name="dbus-daemon" dev="dm-1" ino=6695040 scontext=system_u:system_r:xdm_t:s0-s0:c0.c1023 tcontext=system_u:object_r:dbusd_exec_t:s0 tclass=file permissive=1
> type=AVC msg=audit(1544626796.378:201): avc: denied { read open } for pid=9973 comm="dbus-launch" path="/usr/bin/dbus-daemon" dev="dm-1" ino=6695040 scontext=system_u:system_r:xdm_t:s0-s0:c0.c1023 tcontext=system_u:object_r:dbusd_exec_t:s0 tclass=file permissive=1
> type=AVC msg=audit(1544626796.378:201): avc: denied { execute_no_trans } for pid=9973 comm="dbus-launch" path="/usr/bin/dbus-daemon" dev="dm-1" ino=6695040 scontext=system_u:system_r:xdm_t:s0-s0:c0.c1023 tcontext=system_u:object_r:dbusd_exec_t:s0 tclass=file permissive=1
> type=AVC msg=audit(1544626796.378:201): avc: denied { map } for pid=9973 comm="dbus-daemon" path="/usr/bin/dbus-daemon" dev="dm-1" ino=6695040 scontext=system_u:system_r:xdm_t:s0-s0:c0.c1023 tcontext=system_u:object_r:dbusd_exec_t:s0 tclass=file permissive=1
> type=AVC msg=audit(1546551459.112:208): avc: denied { getcap } for pid=6275 comm="dbus-daemon" scontext=system_u:system_r:xdm_t:s0-s0:c0.c1023 tcontext=system_u:system_r:xdm_t:s0-s0:c0.c1023 tclass=process permissive=1
>
> Signed-off-by: Dave Sugar <dsugar@xxxxxxxxxx>
> ---
> policy/modules/services/dbus.if | 21 +++++++++++++++++++++
> policy/modules/services/xserver.te | 1 +
> 2 files changed, 22 insertions(+)
>
> diff --git a/policy/modules/services/dbus.if b/policy/modules/services/dbus.if
> index ef829e30..d0eec745 100644
> --- a/policy/modules/services/dbus.if
> +++ b/policy/modules/services/dbus.if
> @@ -17,6 +17,27 @@ interface(`dbus_stub',`
> ')
> ')
>
> +########################################
> +## <summary>
> +## Execute dbus in the caller domain.
> +## </summary>
> +## <param name="domain">
> +## <summary>
> +## Domain allowed access.
> +## </summary>
> +## </param>
> +#
> +interface(`dbus_exec',`
> + gen_require(`
> + type dbusd_exec_t;
> + ')
> +
> + corecmd_search_bin($1)
> + can_exec($1, dbusd_exec_t)
> +
> + allow $1 self:process getcap;
I would not enclose the getcap rule here. For example I do not believe
you need that permission to be able to `dbus-daemon --version`. Instead I
would add that rule to xserver.te:
allow xdm_t self:process getcap;
> +')
> +
> ########################################
> ## <summary>
> ## Role access for dbus.
> diff --git a/policy/modules/services/xserver.te b/policy/modules/services/xserver.te
> index fa7ce88e..cc717e7f 100644
> --- a/policy/modules/services/xserver.te
> +++ b/policy/modules/services/xserver.te
> @@ -566,6 +566,7 @@ optional_policy(`
> ')
>
> optional_policy(`
> + dbus_exec(xdm_t)
> dbus_system_bus_client(xdm_t)
> dbus_connect_system_bus(xdm_t)
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Dominick Grift
