| Message ID | 5aea5786954da170e171fc9ddd1f591c0e36afc7.1508524595.git.brdeoliv@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 2017-10-20 at 17:19 -0200, Bruno E. O. Meneguele wrote: > A static variable sig_enforce is used as status var to indicate the real > value of CONFIG_MODULE_SIG_FORCE, once this one is set the var will hold > true, but if the CONFIG is not set the status var will hold whatever > value is present in the module.sig_enforce kernel cmdline param: true > when =1 and false when =0 or not present. > > Considering this cmdline param take place over the CONFIG value when > it's not set, other places in the kernel could missbehave since they ^misbehave > would have only the CONFIG_MODULE_SIG_FORCE value to rely on. Exporting > this status var allows the kernel to rely in the effective value of > module signature enforcement, being it from CONFIG value or cmdline > param. Thanks! There's a minor checkpatch warning below. > Signed-off-by: Bruno E. O. Meneguele <brdeoliv@redhat.com> > --- > include/linux/module.h | 2 ++ > kernel/module.c | 8 ++++++++ > 2 files changed, 10 insertions(+) > > diff --git a/include/linux/module.h b/include/linux/module.h > index fe5aa3736707..ddfe17e3a85c 100644 > --- a/include/linux/module.h > +++ b/include/linux/module.h > @@ -806,4 +806,6 @@ static inline bool module_sig_ok(struct module *module) > } > #endif /* CONFIG_MODULE_SIG */ > > +bool is_module_sig_enforced(void); > + > #endif /* _LINUX_MODULE_H */ > diff --git a/kernel/module.c b/kernel/module.c > index de66ec825992..b93c7ff44066 100644 > --- a/kernel/module.c > +++ b/kernel/module.c > @@ -278,6 +278,14 @@ static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); > module_param(sig_enforce, bool_enable_only, 0644); > #endif /* !CONFIG_MODULE_SIG_FORCE */ > > +/* Export sig_enforce kernel cmdline parameter to allow other subsystems rely > + * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. */ Checkpatch complains. Please use the normal format: /* * */ > +bool is_module_sig_enforced(void) > +{ > + return sig_enforce; > +} > +EXPORT_SYMBOL(is_module_sig_enforced); > + > /* Block module loading/unloading? */ > int modules_disabled = 0; > core_param(nomodule, modules_disabled, bint, 0);
On 23-10, Mimi Zohar wrote: > On Fri, 2017-10-20 at 17:19 -0200, Bruno E. O. Meneguele wrote: > > A static variable sig_enforce is used as status var to indicate the real > > value of CONFIG_MODULE_SIG_FORCE, once this one is set the var will hold > > true, but if the CONFIG is not set the status var will hold whatever > > value is present in the module.sig_enforce kernel cmdline param: true > > when =1 and false when =0 or not present. > > > > Considering this cmdline param take place over the CONFIG value when > > it's not set, other places in the kernel could missbehave since they > > ^misbehave > right. > > would have only the CONFIG_MODULE_SIG_FORCE value to rely on. Exporting > > this status var allows the kernel to rely in the effective value of > > module signature enforcement, being it from CONFIG value or cmdline > > param. > > Thanks! There's a minor checkpatch warning below. > > > Signed-off-by: Bruno E. O. Meneguele <brdeoliv@redhat.com> > > --- > > include/linux/module.h | 2 ++ > > kernel/module.c | 8 ++++++++ > > 2 files changed, 10 insertions(+) > > > > diff --git a/include/linux/module.h b/include/linux/module.h > > index fe5aa3736707..ddfe17e3a85c 100644 > > --- a/include/linux/module.h > > +++ b/include/linux/module.h > > @@ -806,4 +806,6 @@ static inline bool module_sig_ok(struct module *module) > > } > > #endif /* CONFIG_MODULE_SIG */ > > > > +bool is_module_sig_enforced(void); > > + > > #endif /* _LINUX_MODULE_H */ > > diff --git a/kernel/module.c b/kernel/module.c > > index de66ec825992..b93c7ff44066 100644 > > --- a/kernel/module.c > > +++ b/kernel/module.c > > @@ -278,6 +278,14 @@ static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); > > module_param(sig_enforce, bool_enable_only, 0644); > > #endif /* !CONFIG_MODULE_SIG_FORCE */ > > > > +/* Export sig_enforce kernel cmdline parameter to allow other subsystems rely > > + * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. */ > > Checkpatch complains. Please use the normal format: > /* > * > */ > Oh, sure, sorry for that! I'll resend a v2 of the patchset in a minute. Thanks. > > +bool is_module_sig_enforced(void) > > +{ > > + return sig_enforce; > > +} > > +EXPORT_SYMBOL(is_module_sig_enforced); > > + > > /* Block module loading/unloading? */ > > int modules_disabled = 0; > > core_param(nomodule, modules_disabled, bint, 0); >
diff --git a/include/linux/module.h b/include/linux/module.h index fe5aa3736707..ddfe17e3a85c 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -806,4 +806,6 @@ static inline bool module_sig_ok(struct module *module) } #endif /* CONFIG_MODULE_SIG */ +bool is_module_sig_enforced(void); + #endif /* _LINUX_MODULE_H */ diff --git a/kernel/module.c b/kernel/module.c index de66ec825992..b93c7ff44066 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -278,6 +278,14 @@ static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); module_param(sig_enforce, bool_enable_only, 0644); #endif /* !CONFIG_MODULE_SIG_FORCE */ +/* Export sig_enforce kernel cmdline parameter to allow other subsystems rely + * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. */ +bool is_module_sig_enforced(void) +{ + return sig_enforce; +} +EXPORT_SYMBOL(is_module_sig_enforced); + /* Block module loading/unloading? */ int modules_disabled = 0; core_param(nomodule, modules_disabled, bint, 0);
A static variable sig_enforce is used as status var to indicate the real value of CONFIG_MODULE_SIG_FORCE, once this one is set the var will hold true, but if the CONFIG is not set the status var will hold whatever value is present in the module.sig_enforce kernel cmdline param: true when =1 and false when =0 or not present. Considering this cmdline param take place over the CONFIG value when it's not set, other places in the kernel could missbehave since they would have only the CONFIG_MODULE_SIG_FORCE value to rely on. Exporting this status var allows the kernel to rely in the effective value of module signature enforcement, being it from CONFIG value or cmdline param. Signed-off-by: Bruno E. O. Meneguele <brdeoliv@redhat.com> --- include/linux/module.h | 2 ++ kernel/module.c | 8 ++++++++ 2 files changed, 10 insertions(+)