From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by passt.top (Postfix, from userid 1000) id 6152E5A0272; Fri, 28 Feb 2025 01:28:59 +0100 (CET) From: Stefano Brivio To: passt-dev@passt.top Subject: [PATCH] selinux: Fixes/workarounds for passt and passt-repair, mostly for libvirt usage Date: Fri, 28 Feb 2025 01:28:59 +0100 Message-ID: <20250228002859.1544401-1-sbrivio@redhat.com> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: SKLLPIU3XLAI3PUGNCGLABXHZP4H2Q5M X-Message-ID-Hash: SKLLPIU3XLAI3PUGNCGLABXHZP4H2Q5M X-MailFrom: sbrivio@passt.top X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Here are a bunch of workarounds and a couple of fixes for libvirt usage which are rather hard to split into single logical patches as there appear to be some obscure dependencies between some of them: - passt-repair needs to have an exec_type typeattribute (otherwise the policy for lsmd(1) causes a violation on getattr on its executable) file, and that typeattribute just happened to be there for passt as a result of init_daemon_domain(), but passt-repair isn't a daemon, so we need an explicit corecmd_executable_file() - passt-repair needs a workaround, which I'll revisit once https://github.com/fedora-selinux/selinux-policy/issues/2579 is solved, for usage with libvirt: allow it to use qemu_var_run_t and virt_var_run_t sockets - add 'bpf' and 'dac_read_search' capabilities for passt-repair: they are needed (for whatever reason I didn't investigate) to actually receive socket files via SCM_RIGHTS - passt needs further workarounds in the sense of https://github.com/fedora-selinux/selinux-policy/issues/2579: allow it to use map and use svirt_tmpfs_t (not just svirt_image_t): it depends on where the libvirt guest image is - ...it also needs to map /dev/null if is enabled in libvirt's XML for the memoryBacking object, for vhost-user operation - and 'ioctl' on the TCP socket appears to be actually needed, on top of 'getattr', to dump some socket parameters Signed-off-by: Stefano Brivio --- contrib/selinux/passt-repair.te | 33 +++++++++++++++++++++++++++++++-- contrib/selinux/passt.te | 9 +++++++-- 2 files changed, 38 insertions(+), 4 deletions(-) diff --git a/contrib/selinux/passt-repair.te b/contrib/selinux/passt-repair.te index e3ffbcd..f171be6 100644 --- a/contrib/selinux/passt-repair.te +++ b/contrib/selinux/passt-repair.te @@ -28,12 +28,22 @@ require { type console_device_t; type user_devpts_t; type user_tmp_t; + + # Workaround: passt-repair needs to needs to access socket files + # that passt, started by libvirt, might create under different + # labels, depending on whether passt is started as root or not. + # + # However, libvirt doesn't maintain its own policy, which makes + # updates particularly complicated. To avoid breakage in the short + # term, deal with that in passt's own policy. + type qemu_var_run_t; + type virt_var_run_t; } type passt_repair_t; domain_type(passt_repair_t); type passt_repair_exec_t; -files_type(passt_repair_exec_t); +corecmd_executable_file(passt_repair_exec_t); role unconfined_r types passt_repair_t; @@ -41,7 +51,8 @@ allow passt_repair_t passt_repair_exec_t:file { read execute execute_no_trans en type_transition unconfined_t passt_repair_exec_t:process passt_repair_t; allow unconfined_t passt_repair_t:process transition; -allow passt_repair_t self:capability { dac_override net_admin net_raw }; +allow passt_repair_t self:capability { dac_override dac_read_search net_admin net_raw }; +allow passt_repair_t self:capability2 bpf; allow passt_repair_t console_device_t:chr_file { append open getattr read write ioctl }; allow passt_repair_t user_devpts_t:chr_file { append open getattr read write ioctl }; @@ -50,9 +61,27 @@ allow passt_repair_t unconfined_t:unix_stream_socket { connectto read write }; allow passt_repair_t passt_t:unix_stream_socket { connectto read write }; allow passt_repair_t user_tmp_t:unix_stream_socket { connectto read write }; +allow passt_repair_t user_tmp_t:dir search; + allow passt_repair_t unconfined_t:sock_file { read write }; allow passt_repair_t passt_t:sock_file { read write }; allow passt_repair_t user_tmp_t:sock_file { read write }; allow passt_repair_t unconfined_t:tcp_socket { read setopt write }; allow passt_repair_t passt_t:tcp_socket { read setopt write }; + +# Workaround: passt-repair needs to needs to access socket files +# that passt, started by libvirt, might create under different +# labels, depending on whether passt is started as root or not. +# +# However, libvirt doesn't maintain its own policy, which makes +# updates particularly complicated. To avoid breakage in the short +# term, deal with that in passt's own policy. +allow passt_repair_t qemu_var_run_t:unix_stream_socket { connectto read write }; +allow passt_repair_t virt_var_run_t:unix_stream_socket { connectto read write }; + +allow passt_repair_t qemu_var_run_t:dir search; +allow passt_repair_t virt_var_run_t:dir search; + +allow passt_repair_t qemu_var_run_t:sock_file { read write }; +allow passt_repair_t virt_var_run_t:sock_file { read write }; diff --git a/contrib/selinux/passt.te b/contrib/selinux/passt.te index f595079..f8ea672 100644 --- a/contrib/selinux/passt.te +++ b/contrib/selinux/passt.te @@ -29,6 +29,9 @@ require { # particularly complicated. To avoid breakage in the short term, # deal with it in passt's own policy. type svirt_image_t; + type svirt_tmpfs_t; + type svirt_t; + type null_device_t; class file { ioctl getattr setattr create read write unlink open relabelto execute execute_no_trans map }; class dir { search write add_name remove_name mounton }; @@ -45,7 +48,7 @@ require { type net_conf_t; type proc_net_t; type node_t; - class tcp_socket { create accept listen name_bind name_connect getattr }; + class tcp_socket { create accept listen name_bind name_connect getattr ioctl }; class udp_socket { create accept listen }; class icmp_socket { bind create name_bind node_bind setopt read write }; class sock_file { create unlink write }; @@ -129,7 +132,7 @@ corenet_udp_sendrecv_all_ports(passt_t) allow passt_t node_t:icmp_socket { name_bind node_bind }; allow passt_t port_t:icmp_socket name_bind; -allow passt_t self:tcp_socket { create getopt setopt connect bind listen accept shutdown read write getattr }; +allow passt_t self:tcp_socket { create getopt setopt connect bind listen accept shutdown read write getattr ioctl }; allow passt_t self:udp_socket { create getopt setopt connect bind read write }; allow passt_t self:icmp_socket { bind create setopt read write }; @@ -143,3 +146,5 @@ allow passt_t unconfined_t:unix_stream_socket { read write }; # particularly complicated. To avoid breakage in the short term, # deal with it in passt's own policy. allow passt_t svirt_image_t:file { read write map }; +allow passt_t svirt_tmpfs_t:file { read write map }; +allow passt_t null_device_t:chr_file map; -- 2.43.0