| Message ID | 20220322140344.556474-2-atomlin@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | module: core code clean up | expand |
Aaron Tomlin <atomlin@redhat.com> wrote: > No functional changes. I could be mistaken, but I think this has a functional change and could break module signature enforcement in some cases. > > This patch moves all module related code into a separate directory, > modifies each file name and creates a new Makefile. Note: this effort > is in preparation to refactor core module code. > > Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> > Signed-off-by: Aaron Tomlin <atomlin@redhat.com> > --- > MAINTAINERS | 2 +- > kernel/Makefile | 5 +---- > kernel/module/Makefile | 12 ++++++++++++ > kernel/{module_decompress.c => module/decompress.c} | 2 +- > kernel/{module-internal.h => module/internal.h} | 0 > kernel/{module.c => module/main.c} | 2 +- > kernel/{module_signing.c => module/signing.c} | 2 +- I spent at least an hour trying to figure out how the code below in module/signing.c (was moved from module/main.c in a later patch in this series) managed to have a "module" prefix for "module.sig_enforce" kernel cmdline param and for the /sys/module/module/parameters/sig_enforce file. static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); module_param(sig_enforce, bool_enable_only, 0644); I thought I was missing something until I realized this was a very recent change and might actually be a bug. If I'm not mistaken, the prefix will now become "signing". So the kernel cmdline param would get ignore and any userspace writes to /sys/module/module/parameters/sig_enforce will start failing. I don't have a device to boot 5.19-rcX in, but I think I'm right. Can someone confirm? If my code analysis is right, then the fix seems to be adding this code before the module_param() line. diff --git a/kernel/module/signing.c b/kernel/module/signing.c index 85c8999dfecf..6b0672e4417b 100644 --- a/kernel/module/signing.c +++ b/kernel/module/signing.c @@ -16,6 +16,11 @@ #include <uapi/linux/module.h> #include "internal.h" +#ifdef MODULE_PARAM_PREFIX +#undef MODULE_PARAM_PREFIX +#endif +#define MODULE_PARAM_PREFIX "module." + static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); module_param(sig_enforce, bool_enable_only, 0644); -Saravana
On Wed, Jun 01, 2022 at 08:41:11PM -0700, Saravana Kannan wrote: > Aaron Tomlin <atomlin@redhat.com> wrote: > > No functional changes. > > I could be mistaken, but I think this has a functional change and could > break module signature enforcement in some cases. > > > > > This patch moves all module related code into a separate directory, > > modifies each file name and creates a new Makefile. Note: this effort > > is in preparation to refactor core module code. > > > > Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> > > Signed-off-by: Aaron Tomlin <atomlin@redhat.com> > > --- > > MAINTAINERS | 2 +- > > kernel/Makefile | 5 +---- > > kernel/module/Makefile | 12 ++++++++++++ > > kernel/{module_decompress.c => module/decompress.c} | 2 +- > > kernel/{module-internal.h => module/internal.h} | 0 > > kernel/{module.c => module/main.c} | 2 +- > > kernel/{module_signing.c => module/signing.c} | 2 +- > > I spent at least an hour trying to figure out how the code below in > module/signing.c (was moved from module/main.c in a later patch in this > series) managed to have a "module" prefix for "module.sig_enforce" kernel > cmdline param and for the /sys/module/module/parameters/sig_enforce file. > > static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); > module_param(sig_enforce, bool_enable_only, 0644); > > I thought I was missing something until I realized this was a very recent > change and might actually be a bug. If I'm not mistaken, the prefix will > now become "signing". So the kernel cmdline param would get ignore and any > userspace writes to /sys/module/module/parameters/sig_enforce will start > failing. > > I don't have a device to boot 5.19-rcX in, but I think I'm right. Can > someone confirm? > > If my code analysis is right, then the fix seems to be adding this code > before the module_param() line. > > diff --git a/kernel/module/signing.c b/kernel/module/signing.c > index 85c8999dfecf..6b0672e4417b 100644 > --- a/kernel/module/signing.c > +++ b/kernel/module/signing.c > @@ -16,6 +16,11 @@ > #include <uapi/linux/module.h> > #include "internal.h" > > +#ifdef MODULE_PARAM_PREFIX > +#undef MODULE_PARAM_PREFIX > +#endif > +#define MODULE_PARAM_PREFIX "module." > + > static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); > module_param(sig_enforce, bool_enable_only, 0644); That fix would make sense, can you send a proper patch ? The form: #ifdef MODULE_PARAM_PREFIX #undef MODULE_PARAM_PREFIX #endif #define MODULE_PARAM_PREFIX "whatever." Is surprisingly actuaclly quite common, later on we should add helper to make these more well known. Right now this is obscure tribal knowledge when splitting up files. Luis
diff --git a/MAINTAINERS b/MAINTAINERS index 4386b12f86e8..012c9f55a06d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13045,7 +13045,7 @@ L: linux-kernel@vger.kernel.org S: Maintained T: git git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git modules-next F: include/linux/module.h -F: kernel/module.c +F: kernel/module/ MONOLITHIC POWER SYSTEM PMIC DRIVER M: Saravanan Sekar <sravanhome@gmail.com> diff --git a/kernel/Makefile b/kernel/Makefile index 56f4ee97f328..717075b65deb 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -29,7 +29,6 @@ KCOV_INSTRUMENT_softirq.o := n KCSAN_SANITIZE_softirq.o = n # These are called from save_stack_trace() on slub debug path, # and produce insane amounts of uninteresting coverage. -KCOV_INSTRUMENT_module.o := n KCOV_INSTRUMENT_extable.o := n KCOV_INSTRUMENT_stacktrace.o := n # Don't self-instrument. @@ -53,6 +52,7 @@ obj-y += rcu/ obj-y += livepatch/ obj-y += dma/ obj-y += entry/ +obj-$(CONFIG_MODULES) += module/ obj-$(CONFIG_KCMP) += kcmp.o obj-$(CONFIG_FREEZER) += freezer.o @@ -66,9 +66,6 @@ ifneq ($(CONFIG_SMP),y) obj-y += up.o endif obj-$(CONFIG_UID16) += uid16.o -obj-$(CONFIG_MODULES) += module.o -obj-$(CONFIG_MODULE_DECOMPRESS) += module_decompress.o -obj-$(CONFIG_MODULE_SIG) += module_signing.o obj-$(CONFIG_MODULE_SIG_FORMAT) += module_signature.o obj-$(CONFIG_KALLSYMS) += kallsyms.o obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o diff --git a/kernel/module/Makefile b/kernel/module/Makefile new file mode 100644 index 000000000000..cdd5c61b8c7f --- /dev/null +++ b/kernel/module/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Makefile for linux kernel module support +# + +# These are called from save_stack_trace() on slub debug path, +# and produce insane amounts of uninteresting coverage. +KCOV_INSTRUMENT_module.o := n + +obj-y += main.o +obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o +obj-$(CONFIG_MODULE_SIG) += signing.o diff --git a/kernel/module_decompress.c b/kernel/module/decompress.c similarity index 99% rename from kernel/module_decompress.c rename to kernel/module/decompress.c index ffef98a20320..d14d6443225a 100644 --- a/kernel/module_decompress.c +++ b/kernel/module/decompress.c @@ -12,7 +12,7 @@ #include <linux/sysfs.h> #include <linux/vmalloc.h> -#include "module-internal.h" +#include "internal.h" static int module_extend_max_pages(struct load_info *info, unsigned int extent) { diff --git a/kernel/module-internal.h b/kernel/module/internal.h similarity index 100% rename from kernel/module-internal.h rename to kernel/module/internal.h diff --git a/kernel/module.c b/kernel/module/main.c similarity index 99% rename from kernel/module.c rename to kernel/module/main.c index 46a5c2ed1928..34a2b0cf3c3e 100644 --- a/kernel/module.c +++ b/kernel/module/main.c @@ -58,7 +58,7 @@ #include <linux/dynamic_debug.h> #include <linux/audit.h> #include <uapi/linux/module.h> -#include "module-internal.h" +#include "internal.h" #define CREATE_TRACE_POINTS #include <trace/events/module.h> diff --git a/kernel/module_signing.c b/kernel/module/signing.c similarity index 97% rename from kernel/module_signing.c rename to kernel/module/signing.c index 8723ae70ea1f..8aeb6d2ee94b 100644 --- a/kernel/module_signing.c +++ b/kernel/module/signing.c @@ -12,7 +12,7 @@ #include <linux/string.h> #include <linux/verification.h> #include <crypto/public_key.h> -#include "module-internal.h" +#include "internal.h" /* * Verify the signature on a module.