lkml.org 
[lkml]   [2019]   [Jun]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH V31 07/25] kexec_file: Restrict at runtime if the kernel is locked down
On 03/26/19 at 11:27am, Matthew Garrett wrote:
> From: Jiri Bohac <jbohac@suse.cz>
>
> When KEXEC_SIG is not enabled, kernel should not load images through
> kexec_file systemcall if the kernel is locked down.
>
> [Modified by David Howells to fit with modifications to the previous patch
> and to return -EPERM if the kernel is locked down for consistency with
> other lockdowns. Modified by Matthew Garrett to remove the IMA
> integration, which will be replaced by integrating with the IMA
> architecture policy patches.]
>
> Signed-off-by: Jiri Bohac <jbohac@suse.cz>
> Signed-off-by: David Howells <dhowells@redhat.com>
> Signed-off-by: Matthew Garrett <mjg59@google.com>
> Reviewed-by: Jiri Bohac <jbohac@suse.cz>
> cc: kexec@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 67f3a866eabe..a1cc37c8b43b 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -239,6 +239,12 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
> }
>
> ret = 0;
> +
> + if (kernel_is_locked_down(reason, LOCKDOWN_INTEGRITY)) {
> + ret = -EPERM;
> + goto out;
> + }
> +

Checking here is late, it would be good to move the check to earlier
code around below code:
/* We only trust the superuser with rebooting the system. */
if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
return -EPERM;

> break;
>
> /* All other errors are fatal, including nomem, unparseable
> --
> 2.21.0.392.gf8f6787159e-goog
>
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

Thanks
Dave

\
 
 \ /
  Last update: 2019-06-21 08:45    [W:0.192 / U:0.288 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site