| Message ID | 1527160176-29269-3-git-send-email-zohar@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Mimi Zohar <zohar@linux.vnet.ibm.com> writes: > In order for LSMs and IMA-appraisal to differentiate between the > original and new syscalls, both the original and new syscalls must call > an LSM hook. This patch adds a call to security_kernel_read_data() in > the original kexec syscall. Until the lsm hook mess gets cleaned up. Nacked-by: "Eric W. Biederman" <ebiederm@xmission.com> > > Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> > Cc: Eric Biederman <ebiederm@xmission.com> > Cc: Luis R. Rodriguez <mcgrof@kernel.org> > Cc: Kees Cook <keescook@chromium.org> > Cc: David Howells <dhowells@redhat.com> > --- > kernel/kexec.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/kernel/kexec.c b/kernel/kexec.c > index aed8fb2564b3..061ada41c18c 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -11,6 +11,7 @@ > #include <linux/capability.h> > #include <linux/mm.h> > #include <linux/file.h> > +#include <linux/security.h> > #include <linux/kexec.h> > #include <linux/mutex.h> > #include <linux/list.h> > @@ -195,10 +196,17 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments, > static inline int kexec_load_check(unsigned long nr_segments, > unsigned long flags) > { > + int result; > + > /* We only trust the superuser with rebooting the system. */ > if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) > return -EPERM; > > + /* Permit LSMs and IMA to fail the kexec */ > + result = security_kernel_read_data(NULL, READING_KEXEC_IMAGE); > + if (result < 0) > + return result; > + > /* > * Verify we have a legal set of flags > * This leaves us room for future extensions.
diff --git a/kernel/kexec.c b/kernel/kexec.c index aed8fb2564b3..061ada41c18c 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -11,6 +11,7 @@ #include <linux/capability.h> #include <linux/mm.h> #include <linux/file.h> +#include <linux/security.h> #include <linux/kexec.h> #include <linux/mutex.h> #include <linux/list.h> @@ -195,10 +196,17 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments, static inline int kexec_load_check(unsigned long nr_segments, unsigned long flags) { + int result; + /* We only trust the superuser with rebooting the system. */ if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) return -EPERM; + /* Permit LSMs and IMA to fail the kexec */ + result = security_kernel_read_data(NULL, READING_KEXEC_IMAGE); + if (result < 0) + return result; + /* * Verify we have a legal set of flags * This leaves us room for future extensions.
In order for LSMs and IMA-appraisal to differentiate between the original and new syscalls, both the original and new syscalls must call an LSM hook. This patch adds a call to security_kernel_read_data() in the original kexec syscall. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: David Howells <dhowells@redhat.com> --- kernel/kexec.c | 8 ++++++++ 1 file changed, 8 insertions(+)