| Message ID | 11786.1510246325@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Nov 09, 2017 at 04:52:05PM +0000, David Howells wrote: > Hi, > > I need to lock down kprobes under secure boot conditions as part of the patch > series that can be found here: > > https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=efi-lock-down > > Can you tell me that if the attached patch is sufficient to the cause? Yes, this patch will prevent any kprobe registration. Ananth > > Thanks, > David > --- > commit ffb3484d6e0f1d625f8e84a6a19c139a28a52499 > Author: David Howells <dhowells@redhat.com> > Date: Wed Nov 8 16:14:12 2017 +0000 > > Lock down kprobes > > Disallow the creation of kprobes when the kernel is locked down by > preventing their registration. This prevents kprobes from being used to > access kernel memory, either to make modifications or to steal crypto data. > > Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> > Signed-off-by: David Howells <dhowells@redhat.com> > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index a1606a4224e1..f06023b0936c 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -1530,6 +1530,9 @@ int register_kprobe(struct kprobe *p) > struct module *probed_mod; > kprobe_opcode_t *addr; > > + if (kernel_is_locked_down("Use of kprobes")) > + return -EPERM; > + > /* Adjust probe address from symbol */ > addr = kprobe_addr(p); > if (IS_ERR(addr)) -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> wrote:
> Yes, this patch will prevent any kprobe registration.
Can I put that down as a Reviewed-by?
David
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Nov 09, 2017 at 09:54:50PM +0000, David Howells wrote: > Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> wrote: > > > Yes, this patch will prevent any kprobe registration. > > Can I put that down as a Reviewed-by? Reviewed-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi David, On Thu, 09 Nov 2017 16:52:05 +0000 David Howells <dhowells@redhat.com> wrote: > > Lock down kprobes > > Disallow the creation of kprobes when the kernel is locked down by > preventing their registration. This prevents kprobes from being used to > access kernel memory, either to make modifications or to steal crypto data. Is that locked-down flag changed while running the kernel, or only specified by boot parameter? If that can happen while running, we have to take care of enabling/disabling unregistering etc. too. Thank you, > > Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> > Signed-off-by: David Howells <dhowells@redhat.com> > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index a1606a4224e1..f06023b0936c 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -1530,6 +1530,9 @@ int register_kprobe(struct kprobe *p) > struct module *probed_mod; > kprobe_opcode_t *addr; > > + if (kernel_is_locked_down("Use of kprobes")) > + return -EPERM; > + > /* Adjust probe address from symbol */ > addr = kprobe_addr(p); > if (IS_ERR(addr))
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index a1606a4224e1..f06023b0936c 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1530,6 +1530,9 @@ int register_kprobe(struct kprobe *p) struct module *probed_mod; kprobe_opcode_t *addr; + if (kernel_is_locked_down("Use of kprobes")) + return -EPERM; + /* Adjust probe address from symbol */ addr = kprobe_addr(p); if (IS_ERR(addr))
Hi, I need to lock down kprobes under secure boot conditions as part of the patch series that can be found here: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=efi-lock-down Can you tell me that if the attached patch is sufficient to the cause? Thanks, David --- commit ffb3484d6e0f1d625f8e84a6a19c139a28a52499 Author: David Howells <dhowells@redhat.com> Date: Wed Nov 8 16:14:12 2017 +0000 Lock down kprobes Disallow the creation of kprobes when the kernel is locked down by preventing their registration. This prevents kprobes from being used to access kernel memory, either to make modifications or to steal crypto data. Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html