Re: [PATCH V31 07/25] kexec_file: Restrict at runtime if the kernel is locked down
From: Dave Young <hidden>
Date: 2019-06-21 06:43:53
Also in:
kexec, linux-security-module, lkml
On 03/26/19 at 11:27am, Matthew Garrett wrote:
quoted hunk ↗ jump to hunk
From: Jiri Bohac <redacted> 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 <redacted> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Matthew Garrett <redacted> Reviewed-by: Jiri Bohac <redacted> 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