Re: [libvirt] [PATCH 2/2] Rework lxc apparmor profile

Quoting Cédric Bosdonnat (cbosdonnat(a)suse.com): > Rework the apparmor lxc profile abstraction to mimic ubuntu's container-default. > This profile allows quite a lot, but strives to restrict access to > dangerous resources. > > Removing the explicit authorizations to bash, systemd and cron files, > forces them to keep the lxc profile for all applications inside the > container. PUx permissions where leading to running systemd (and others > tasks) unconfined. > > Put the generic files, network and capabilities restrictions directly > in the TEMPLATE.lxc: this way, users can restrict them on a per > container basis. > --- > examples/apparmor/Makefile.am | 6 +- > examples/apparmor/TEMPLATE.lxc | 15 ++++ > examples/apparmor/{TEMPLATE => TEMPLATE.qemu} | 2 +- > examples/apparmor/libvirt-lxc | 119 +++++++++++++++++++++++--- > src/security/security_apparmor.c | 20 +++-- > src/security/virt-aa-helper.c | 29 +------ > 6 files changed, 148 insertions(+), 43 deletions(-) > create mode 100644 examples/apparmor/TEMPLATE.lxc > rename examples/apparmor/{TEMPLATE => TEMPLATE.qemu} (75%) > > diff --git a/examples/apparmor/Makefile.am b/examples/apparmor/Makefile.am > index a741e94..7a20e16 100644 > --- a/examples/apparmor/Makefile.am > +++ b/examples/apparmor/Makefile.am > @@ -15,7 +15,8 @@ > ## <http://www.gnu.org/licenses/>;. > > EXTRA_DIST= \ > - TEMPLATE \ > + TEMPLATE.qemu \ > + TEMPLATE.lxc \ > libvirt-qemu \ > libvirt-lxc \ > usr.lib.libvirt.virt-aa-helper \ > @@ -36,6 +37,7 @@ abstractions_DATA = \ > > templatesdir = $(apparmordir)/libvirt > templates_DATA = \ > - TEMPLATE \ > + TEMPLATE.qemu \ > + TEMPLATE.lxc \ > $(NULL) > endif WITH_APPARMOR_PROFILES > diff --git a/examples/apparmor/TEMPLATE.lxc b/examples/apparmor/TEMPLATE.lxc > new file mode 100644 > index 0000000..7b64885 > --- /dev/null > +++ b/examples/apparmor/TEMPLATE.lxc > @@ -0,0 +1,15 @@ > +# > +# This profile is for the domain whose UUID matches this file. > +# > + > +#include <tunables/global> > + > +profile LIBVIRT_TEMPLATE { > + #include <abstractions/libvirt-lxc> > + > + # Globally allows everything to run under this profile > + # These can be narrowed depending on the container's use. > + file, > + capability, > + network, > +} > diff --git a/examples/apparmor/TEMPLATE b/examples/apparmor/TEMPLATE.qemu > similarity index 75% > rename from examples/apparmor/TEMPLATE > rename to examples/apparmor/TEMPLATE.qemu > index 187dec5..008a221 100644 > --- a/examples/apparmor/TEMPLATE > +++ b/examples/apparmor/TEMPLATE.qemu > @@ -5,5 +5,5 @@ > #include <tunables/global> > > profile LIBVIRT_TEMPLATE { > - #include <abstractions/libvirt-driver> > + #include <abstractions/libvirt-qemu> > } > diff --git a/examples/apparmor/libvirt-lxc b/examples/apparmor/libvirt-lxc > index d404328..4bfb503 100644 > --- a/examples/apparmor/libvirt-lxc > +++ b/examples/apparmor/libvirt-lxc > @@ -2,16 +2,115 @@ > > #include <abstractions/base> > > - # Needed for lxc-enter-namespace > - capability sys_admin, > - capability sys_chroot, > + umount, > > - # Added for lxc-enter-namespace --cmd /bin/bash > - /bin/bash PUx, > + # ignore DENIED message on / remount > + deny mount options=(ro, remount) -> /, > > - /usr/sbin/cron PUx, > - /usr/lib/systemd/systemd PUx, > + # allow tmpfs mounts everywhere > + mount fstype=tmpfs, > > - /usr/lib/libsystemd-*.so.* mr, > - /usr/lib/libudev-*.so.* mr, > - /etc/ld.so.cache mr, > + # allow mqueue mounts everywhere > + mount fstype=mqueue, > + > + # allow fuse mounts everywhere > + mount fstype=fuse.*, > + > + # deny writes in /proc/sys/fs but allow binfmt_misc to be mounted > + mount fstype=binfmt_misc -> /proc/sys/fs/binfmt_misc/, > + deny @{PROC}/sys/fs/** wklx, > + > + # allow efivars to be mounted, writing to it will be blocked though > + mount fstype=efivarfs -> /sys/firmware/efi/efivars/, > + > + # block some other dangerous paths > + deny @{PROC}/sysrq-trigger rwklx, > + deny @{PROC}/mem rwklx, > + deny @{PROC}/kmem rwklx, > + > + # deny writes in /sys except for /sys/fs/cgroup, also allow > + # fusectl, securityfs and debugfs to be mounted there (read-only) > + mount fstype=fusectl -> /sys/fs/fuse/connections/, > + mount fstype=securityfs -> /sys/kernel/security/, > + mount fstype=debugfs -> /sys/kernel/debug/, > + mount fstype=proc -> /proc/, > + mount fstype=sysfs -> /sys/, > + deny /sys/firmware/efi/efivars/** rwklx, > + deny /sys/kernel/security/** rwklx, > + > + # generated by: lxc-generate-aa-rules.py container-rules.base > + deny /proc/sys/[^kn]*{,/**} wklx, > + deny /proc/sys/k[^e]*{,/**} wklx, > + deny /proc/sys/ke[^r]*{,/**} wklx, > + deny /proc/sys/ker[^n]*{,/**} wklx, > + deny /proc/sys/kern[^e]*{,/**} wklx, > + deny /proc/sys/kerne[^l]*{,/**} wklx, > + deny /proc/sys/kernel/[^smhd]*{,/**} wklx, > + deny /proc/sys/kernel/d[^o]*{,/**} wklx, > + deny /proc/sys/kernel/do[^m]*{,/**} wklx, > + deny /proc/sys/kernel/dom[^a]*{,/**} wklx, > + deny /proc/sys/kernel/doma[^i]*{,/**} wklx, > + deny /proc/sys/kernel/domai[^n]*{,/**} wklx, > + deny /proc/sys/kernel/domain[^n]*{,/**} wklx, > + deny /proc/sys/kernel/domainn[^a]*{,/**} wklx, > + deny /proc/sys/kernel/domainna[^m]*{,/**} wklx, > + deny /proc/sys/kernel/domainnam[^e]*{,/**} wklx, > + deny /proc/sys/kernel/domainname?*{,/**} wklx, > + deny /proc/sys/kernel/h[^o]*{,/**} wklx, > + deny /proc/sys/kernel/ho[^s]*{,/**} wklx, > + deny /proc/sys/kernel/hos[^t]*{,/**} wklx, > + deny /proc/sys/kernel/host[^n]*{,/**} wklx, > + deny /proc/sys/kernel/hostn[^a]*{,/**} wklx, > + deny /proc/sys/kernel/hostna[^m]*{,/**} wklx, > + deny /proc/sys/kernel/hostnam[^e]*{,/**} wklx, > + deny /proc/sys/kernel/hostname?*{,/**} wklx, > + deny /proc/sys/kernel/m[^s]*{,/**} wklx, > + deny /proc/sys/kernel/ms[^g]*{,/**} wklx, > + deny /proc/sys/kernel/msg*/** wklx, > + deny /proc/sys/kernel/s[^he]*{,/**} wklx, > + deny /proc/sys/kernel/se[^m]*{,/**} wklx, > + deny /proc/sys/kernel/sem*/** wklx, > + deny /proc/sys/kernel/sh[^m]*{,/**} wklx, > + deny /proc/sys/kernel/shm*/** wklx, > + deny /proc/sys/kernel?*{,/**} wklx, > + deny /proc/sys/n[^e]*{,/**} wklx, > + deny /proc/sys/ne[^t]*{,/**} wklx, > + deny /proc/sys/net?*{,/**} wklx, > + deny /sys/[^fdc]*{,/**} wklx, > + deny /sys/c[^l]*{,/**} wklx, > + deny /sys/cl[^a]*{,/**} wklx, > + deny /sys/cla[^s]*{,/**} wklx, > + deny /sys/clas[^s]*{,/**} wklx, > + deny /sys/class/[^n]*{,/**} wklx, > + deny /sys/class/n[^e]*{,/**} wklx, > + deny /sys/class/ne[^t]*{,/**} wklx, > + deny /sys/class/net?*{,/**} wklx, > + deny /sys/class?*{,/**} wklx, > + deny /sys/d[^e]*{,/**} wklx, > + deny /sys/de[^v]*{,/**} wklx, > + deny /sys/dev[^i]*{,/**} wklx, > + deny /sys/devi[^c]*{,/**} wklx, > + deny /sys/devic[^e]*{,/**} wklx, > + deny /sys/device[^s]*{,/**} wklx, > + deny /sys/devices/[^v]*{,/**} wklx, > + deny /sys/devices/v[^i]*{,/**} wklx, > + deny /sys/devices/vi[^r]*{,/**} wklx, > + deny /sys/devices/vir[^t]*{,/**} wklx, > + deny /sys/devices/virt[^u]*{,/**} wklx, > + deny /sys/devices/virtu[^a]*{,/**} wklx, > + deny /sys/devices/virtua[^l]*{,/**} wklx, > + deny /sys/devices/virtual/[^n]*{,/**} wklx, > + deny /sys/devices/virtual/n[^e]*{,/**} wklx, > + deny /sys/devices/virtual/ne[^t]*{,/**} wklx, > + deny /sys/devices/virtual/net?*{,/**} wklx, > + deny /sys/devices/virtual?*{,/**} wklx, > + deny /sys/devices?*{,/**} wklx, > + deny /sys/f[^s]*{,/**} wklx, > + deny /sys/fs/[^c]*{,/**} wklx, > + deny /sys/fs/c[^g]*{,/**} wklx, > + deny /sys/fs/cg[^r]*{,/**} wklx, > + deny /sys/fs/cgr[^o]*{,/**} wklx, > + deny /sys/fs/cgro[^u]*{,/**} wklx, > + deny /sys/fs/cgrou[^p]*{,/**} wklx, > + deny /sys/fs/cgroup?*{,/**} wklx, > + deny /sys/fs?*{,/**} wklx, > diff --git a/src/security/security_apparmor.c b/src/security/security_apparmor.c > index 1e2a38b..778d233 100644 > --- a/src/security/security_apparmor.c > +++ b/src/security/security_apparmor.c > @@ -351,26 +351,36 @@ AppArmorSetSecuritySCSILabel(virSCSIDevicePtr dev ATTRIBUTE_UNUSED, > static int > AppArmorSecurityManagerProbe(const char *virtDriver ATTRIBUTE_UNUSED) > { > - char *template = NULL; > + char *template_qemu = NULL; > + char *template_lxc = NULL; > int rc = SECURITY_DRIVER_DISABLE; > > if (use_apparmor() < 0) > return rc; > > /* see if template file exists */ > - if (virAsprintf(&template, "%s/TEMPLATE", > + if (virAsprintf(&template_qemu, "%s/TEMPLATE.qemu", > APPARMOR_DIR "/libvirt") == -1) > return rc; > > - if (!virFileExists(template)) { > + if (virAsprintf(&template_lxc, "%s/TEMPLATE.lxc", > + APPARMOR_DIR "/libvirt") == -1) Hi, something looks weird here. Is this (two lines above and 5 lines below) intended, or are there missing lines?

> + > + if (!virFileExists(template_qemu)) { > + virReportError(VIR_ERR_INTERNAL_ERROR, > + _("template \'%s\' does not exist"), template_qemu); > + goto cleanup; > + } > + if (!virFileExists(template_lxc)) { > virReportError(VIR_ERR_INTERNAL_ERROR, > - _("template \'%s\' does not exist"), template); > + _("template \'%s\' does not exist"), template_lxc); > goto cleanup; > } > rc = SECURITY_DRIVER_ENABLE; > > cleanup: > - VIR_FREE(template); > + VIR_FREE(template_qemu); > + VIR_FREE(template_lxc); > > return rc; > } > diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c > index d563b98..2a09145 100644 > --- a/src/security/virt-aa-helper.c > +++ b/src/security/virt-aa-helper.c > @@ -336,24 +336,20 @@ create_profile(const char *profile, const char *profile_name, > char *pcontent = NULL; > char *replace_name = NULL; > char *replace_files = NULL; > - char *replace_driver = NULL; > const char *template_name = "\nprofile LIBVIRT_TEMPLATE"; > const char *template_end = "\n}"; > - const char *template_driver = "libvirt-driver"; > int tlen, plen; > int fd; > int rc = -1; > - const char *driver_name = "qemu"; > - > - if (virtType == VIR_DOMAIN_VIRT_LXC) > - driver_name = "lxc"; > > if (virFileExists(profile)) { > vah_error(NULL, 0, _("profile exists")); > goto end; > } > > - if (virAsprintfQuiet(&template, "%s/TEMPLATE", APPARMOR_DIR "/libvirt") < 0) { > + > + if (virAsprintfQuiet(&template, "%s/TEMPLATE.%s", APPARMOR_DIR "/libvirt", > + virDomainVirtTypeToString(virtType)) < 0) { > vah_error(NULL, 0, _("template name exceeds maximum length")); > goto end; > } > @@ -378,11 +374,6 @@ create_profile(const char *profile, const char *profile_name, > goto clean_tcontent; > } > > - if (strstr(tcontent, template_driver) == NULL) { > - vah_error(NULL, 0, _("no replacement string in template")); > - goto clean_tcontent; > - } > - > /* '\nprofile <profile_name>\0' */ > if (virAsprintfQuiet(&replace_name, "\nprofile %s", profile_name) == -1) { > vah_error(NULL, 0, _("could not allocate memory for profile name")); > @@ -397,15 +388,7 @@ create_profile(const char *profile, const char *profile_name, > goto clean_tcontent; > } > > - /* 'libvirt-<driver_name>\0' */ > - if (virAsprintfQuiet(&replace_driver, "libvirt-%s", driver_name) == -1) { > - vah_error(NULL, 0, _("could not allocate memory for profile driver")); > - VIR_FREE(replace_driver); > - goto clean_tcontent; > - } > - > - plen = tlen + strlen(replace_name) - strlen(template_name) + > - strlen(replace_driver) - strlen(template_driver) + 1; > + plen = tlen + strlen(replace_name) - strlen(template_name) + 1; > > if (virtType != VIR_DOMAIN_VIRT_LXC) > plen += strlen(replace_files) - strlen(template_end); > @@ -422,9 +405,6 @@ create_profile(const char *profile, const char *profile_name, > pcontent[0] = '\0'; > strcpy(pcontent, tcontent); > > - if (replace_string(pcontent, plen, template_driver, replace_driver) < 0) > - goto clean_all; > - > if (replace_string(pcontent, plen, template_name, replace_name) < 0) > goto clean_all; > > @@ -455,7 +435,6 @@ create_profile(const char *profile, const char *profile_name, > clean_replace: > VIR_FREE(replace_name); > VIR_FREE(replace_files); > - VIR_FREE(replace_driver); > clean_tcontent: > VIR_FREE(tcontent); > end: > -- > 1.8.4.5 > > -- > libvir-list mailing list > libvir-list(a)redhat.com > https://www.redhat.com/mailman/listinfo/libvir-list