Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxx>
>
> Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
> Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
> Cc: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: David Howells <dhowells@xxxxxxxxxx>
> ---
> 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.
