Of course it isn't. Vivek Goyal <vgoyal at redhat.com> wrote: >On Mon, Dec 09, 2013 at 05:06:10PM -0800, Kees Cook wrote: >> On Mon, Dec 9, 2013 at 4:34 PM, H. Peter Anvin <hpa at zytor.com> wrote: >> > On 12/09/2013 04:16 PM, Kees Cook wrote: >> >> For general-purpose (i.e. distro) kernel builds it makes sense to >build with >> >> CONFIG_KEXEC to allow end users to choose what kind of things they >want to do >> >> with kexec. However, in the face of trying to lock down a system >with such >> >> a kernel, there needs to be a way to disable kexec (much like >module loading >> >> can be disabled). Without this, it is too easy for the root user >to modify >> >> kernel memory even when CONFIG_STRICT_DEVMEM and modules_disabled >are set. >> >> >> >> Signed-off-by: Kees Cook <keescook at chromium.org> >> >> Acked-by: Rik van Riel <riel at redhat.com> >> > >> > So the logic is to load a crashkernel and then lock down the >machine >> > before services, networking etc. are enabled? >> >> Right, or to just turn it off at boot time if kexec will not be used >at all. > >kdump kernel is loaded with the help of kdump service. Different >distro's >might have different dependencies for that serivce. But recently in >fedora >we wait network to come up before starting that service. (So that nfs >targets can be mounted and checked for valid dump destinations). > >IOW, crash kernel is loaded quite late in the game (quite a few >services >have run and possibly networking is up too). To me, practically one >will >disable kdump also if you change state of this knob early. > >Thanks >Vivek -- Sent from my mobile phone. Please pardon brevity and lack of formatting.
