| Message ID | 20180920162338.21060-20-keescook@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | LSM: Explict LSM ordering | expand |
On 9/20/2018 9:23 AM, Kees Cook wrote: > This provides a way to declare LSM initialization order via Kconfig. > > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > security/Kconfig | 11 +++++++++++ > security/security.c | 38 +++++++++++++++++++++++++++++++++++--- > 2 files changed, 46 insertions(+), 3 deletions(-) > > diff --git a/security/Kconfig b/security/Kconfig > index 27d8b2688f75..de8202886c1d 100644 > --- a/security/Kconfig > +++ b/security/Kconfig > @@ -276,5 +276,16 @@ config DEFAULT_SECURITY > default "apparmor" if DEFAULT_SECURITY_APPARMOR > default "" if DEFAULT_SECURITY_DAC > > +config LSM_ORDER > + string "Default initialization order of builtin LSMs" > + default "integrity" I would like to see the default spelled out rather than provided implicitly. + default "integrity,yama,loadpin,selinux,smack,apparmor,tomoyo" > + help > + A comma-separated list of LSMs, in initialization order. > + Any LSMs left off this list will be link-order initialized > + after any listed LSMs. Any LSMs listed here but not built in > + the kernel will be ignored. This should also describe what will happen if you include multiple major modules in the list. > + > + If unsure, leave this as the default. > + > endmenu > > diff --git a/security/security.c b/security/security.c > index 2541a512a0f7..063ee2466e58 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -44,6 +44,8 @@ char *lsm_names; > /* Boot-time LSM user choice */ > static __initdata const char *chosen_major_lsm; > > +static __initconst const char * const builtin_lsm_order = CONFIG_LSM_ORDER; > + > /* Ordered list of LSMs to initialize. */ > static __initdata struct lsm_info **ordered_lsms; > > @@ -108,14 +110,44 @@ static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from) > (!lsm->enabled || *lsm->enabled) ? "en" : "dis"); > } > > -/* Populate ordered LSMs list from hard-coded list of LSMs. */ > +/* Populate ordered LSMs list from given string. */ > +static void __init parse_lsm_order(const char *order, const char *origin) > +{ > + struct lsm_info *lsm; > + char *sep, *name, *next; > + > + sep = kstrdup(order, GFP_KERNEL); > + next = sep; > + /* Walk the list, looking for matching LSMs. */ > + while ((name = strsep(&next, ",")) != NULL) { > + bool found = false; > + > + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { > + if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) == 0 && > + strcmp(lsm->name, name) == 0) { > + append_ordered_lsm(lsm, origin); > + found = true; > + } > + } > + > + if (!found) > + init_debug("%s ignored: %s\n", origin, name); > + } > + kfree(sep); > +} > + > +/* Populate ordered LSMs list from builtin list of LSMs. */ > static void __init prepare_lsm_order(void) > { > struct lsm_info *lsm; > > + /* Parse order from builtin list. */ > + parse_lsm_order(builtin_lsm_order, "builtin"); > + > + /* Add any missing LSMs, in link order. */ > for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { > - if (strcmp(lsm->name, "integrity") == 0) > - append_ordered_lsm(lsm, "builtin"); > + if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) == 0) > + append_ordered_lsm(lsm, "link-time"); > } > } >
On 9/20/2018 5:10 PM, Casey Schaufler wrote: > On 9/20/2018 9:23 AM, Kees Cook wrote: >> This provides a way to declare LSM initialization order via Kconfig. >> >> Signed-off-by: Kees Cook <keescook@chromium.org> >> --- >> security/Kconfig | 11 +++++++++++ >> security/security.c | 38 +++++++++++++++++++++++++++++++++++--- >> 2 files changed, 46 insertions(+), 3 deletions(-) >> >> diff --git a/security/Kconfig b/security/Kconfig >> index 27d8b2688f75..de8202886c1d 100644 >> --- a/security/Kconfig >> +++ b/security/Kconfig >> @@ -276,5 +276,16 @@ config DEFAULT_SECURITY >> default "apparmor" if DEFAULT_SECURITY_APPARMOR >> default "" if DEFAULT_SECURITY_DAC >> >> +config LSM_ORDER >> + string "Default initialization order of builtin LSMs" >> + default "integrity" > I would like to see the default spelled out rather than > provided implicitly. > > + default "integrity,yama,loadpin,selinux,smack,apparmor,tomoyo" I see now that comes later in the patch set. Never mind.
diff --git a/security/Kconfig b/security/Kconfig index 27d8b2688f75..de8202886c1d 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -276,5 +276,16 @@ config DEFAULT_SECURITY default "apparmor" if DEFAULT_SECURITY_APPARMOR default "" if DEFAULT_SECURITY_DAC +config LSM_ORDER + string "Default initialization order of builtin LSMs" + default "integrity" + help + A comma-separated list of LSMs, in initialization order. + Any LSMs left off this list will be link-order initialized + after any listed LSMs. Any LSMs listed here but not built in + the kernel will be ignored. + + If unsure, leave this as the default. + endmenu diff --git a/security/security.c b/security/security.c index 2541a512a0f7..063ee2466e58 100644 --- a/security/security.c +++ b/security/security.c @@ -44,6 +44,8 @@ char *lsm_names; /* Boot-time LSM user choice */ static __initdata const char *chosen_major_lsm; +static __initconst const char * const builtin_lsm_order = CONFIG_LSM_ORDER; + /* Ordered list of LSMs to initialize. */ static __initdata struct lsm_info **ordered_lsms; @@ -108,14 +110,44 @@ static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from) (!lsm->enabled || *lsm->enabled) ? "en" : "dis"); } -/* Populate ordered LSMs list from hard-coded list of LSMs. */ +/* Populate ordered LSMs list from given string. */ +static void __init parse_lsm_order(const char *order, const char *origin) +{ + struct lsm_info *lsm; + char *sep, *name, *next; + + sep = kstrdup(order, GFP_KERNEL); + next = sep; + /* Walk the list, looking for matching LSMs. */ + while ((name = strsep(&next, ",")) != NULL) { + bool found = false; + + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { + if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) == 0 && + strcmp(lsm->name, name) == 0) { + append_ordered_lsm(lsm, origin); + found = true; + } + } + + if (!found) + init_debug("%s ignored: %s\n", origin, name); + } + kfree(sep); +} + +/* Populate ordered LSMs list from builtin list of LSMs. */ static void __init prepare_lsm_order(void) { struct lsm_info *lsm; + /* Parse order from builtin list. */ + parse_lsm_order(builtin_lsm_order, "builtin"); + + /* Add any missing LSMs, in link order. */ for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { - if (strcmp(lsm->name, "integrity") == 0) - append_ordered_lsm(lsm, "builtin"); + if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) == 0) + append_ordered_lsm(lsm, "link-time"); } }
This provides a way to declare LSM initialization order via Kconfig. Signed-off-by: Kees Cook <keescook@chromium.org> --- security/Kconfig | 11 +++++++++++ security/security.c | 38 +++++++++++++++++++++++++++++++++++--- 2 files changed, 46 insertions(+), 3 deletions(-)