[PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set
Dave Young
dyoung at redhat.com
Fri Apr 7 03:05:45 UTC 2017
On 04/05/17 at 09:15pm, David Howells wrote:
> From: Chun-Yi Lee <joeyli.kernel at gmail.com>
>
> When KEXEC_VERIFY_SIG is not enabled, kernel should not loads image
> through kexec_file systemcall if securelevel has been set.
>
> This code was showed in Matthew's patch but not in git:
> https://lkml.org/lkml/2015/3/13/778
>
> Cc: Matthew Garrett <mjg59 at srcf.ucam.org>
> Signed-off-by: Chun-Yi Lee <jlee at suse.com>
> Signed-off-by: David Howells <dhowells at redhat.com>
> cc: kexec at lists.infradead.org
> ---
>
> kernel/kexec_file.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index b118735fea9d..f6937eecd1eb 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -268,6 +268,12 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
> if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
> return -EPERM;
>
> + /* Don't permit images to be loaded into trusted kernels if we're not
> + * going to verify the signature on them
> + */
> + if (!IS_ENABLED(CONFIG_KEXEC_VERIFY_SIG) && kernel_is_locked_down())
> + return -EPERM;
> +
> /* Make sure we have a legal set of flags */
> if (flags != (flags & KEXEC_FILE_FLAGS))
> return -EINVAL;
>
>
> _______________________________________________
> kexec mailing list
> kexec at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
Acked-by: Dave Young <dyoung at redhat.com>
Thanks
Dave
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