On Wed, Sep 19, 2012 at 7:41 AM, Mimi Zohar <zo...@linux.vnet.ibm.com> wrote: > On Wed, 2012-09-19 at 13:08 +0930, Rusty Russell wrote: >> Mimi Zohar <zo...@linux.vnet.ibm.com> writes: >> >> > On Wed, 2012-09-12 at 17:04 +0930, Rusty Russell wrote: >> >> "H. Peter Anvin" <h...@zytor.com> writes: >> >> >> >> > On 09/06/2012 11:13 AM, Kees Cook wrote: >> >> >> Instead of (or in addition to) kernel module signing, being able to >> >> >> reason >> >> >> about the origin of a kernel module would be valuable in situations >> >> >> where an OS already trusts a specific file system, file, etc, due to >> >> >> things like security labels or an existing root of trust to a partition >> >> >> through things like dm-verity. >> >> >> >> >> >> This introduces a new syscall (currently only on x86), similar to >> >> >> init_module, that has only two arguments. The first argument is used as >> >> >> a file descriptor to the module and the second argument is a pointer to >> >> >> the NULL terminated string of module arguments. >> >> >> >> >> > >> >> > Please use the standard naming convention, which is an f- prefix (i.e. >> >> > finit_module()). >> >> >> >> Good point; I just did a replace here. >> > >> > Have you pushed out the changes? And if so, to where? >> >> No, I kept them in my patch series but out of linux-next, since I >> thought you disliked the placement of the security hooks? > > I thought about it some more. The call to > security_kernel_module_from_file() from copy_module_from_user() doesn't > provide any information, not the buffer contents nor the signature. The > only thing IMA-appraisal can do is to fail the request with > INTEGRITY_UNKNOWN. This is reflected in the IMA-appraisal patch I > posted http://marc.info/?l=linux-security-module&m=134739023306344&w=2. > > Please add my Acked-by: Mimi Zohar <zo...@us.ibm.com>
FWIW, this was my intent: it is a way for the LSM to see an attempt to load a module it can't reason about. If it wants to allow it blindly, it can, otherwise is has the option to refuse it. I didn't want to leave the old syscall unhooked. -Kees -- Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
