Messages in this thread Patch in this message | | | From | Matthew Garrett <> | Subject | [PATCH 08/12] kexec: Disable at runtime if trusted_kernel is true | Date | Wed, 26 Feb 2014 15:11:09 -0500 |
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kexec permits the loading and execution of arbitrary code in ring 0, which permits the modification of the running kernel. Prevent this if trusted_kernel is true.
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com> --- kernel/kexec.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/kernel/kexec.c b/kernel/kexec.c index 60bafbe..281ddd0 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -32,6 +32,7 @@ #include <linux/vmalloc.h> #include <linux/swap.h> #include <linux/syscore_ops.h> +#include <linux/security.h> #include <asm/page.h> #include <asm/uaccess.h> @@ -946,6 +947,9 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) return -EPERM; + if (get_trusted_kernel()) + return -EPERM; + /* * Verify we have a legal set of flags * This leaves us room for future extensions. -- 1.8.5.3
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