Messages in this thread |  | | Date | Thu, 13 Feb 2014 22:42:40 +0100 | From | Arend van Spriel <> | Subject | Re: [RFC PATCH] Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE |
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On 02/13/2014 04:44 PM, Steven Rostedt wrote: > On Thu, 13 Feb 2014 10:36:35 -0500 > fche@redhat.com (Frank Ch. Eigler) wrote: > >> >> rostedt wrote: >> >>> [...] >>> Oh! You are saying that if the kernel only *supports* signed modules, >>> and you load a module that is not signed, it will taint the kernel? >> >> Yes: this is the default for several distros. >> > > Rusty, Ingo, > > This looks like a bug to me, as it can affect even in-tree kernel > modules. If you have a kernel that supports signed modules, and you > modify a module, recompile it, apply it, since it is no longer signed, > then it sounds like we just tainted it. Worse yet, we just disabled any > tracepoints on that module, which means it is even harder to debug that > module (if that's the reason you recompiled it in the first place).
When I stumbled upon this issue a while ago on Fedora 19 I built my kernel rpm packages which generates a signature key (.priv and .x509), which I kept safe with the kernel headers. When building recompiling modules I refer to it with MODSECKEY and MODPUBKEY, ie.
$ make MODSECKEY=bla MODPUBKEY=duh \ M=drivers/net/wireless/brcm80211 modules
Or sign it manually using the sign-file perl script:
mod_sign_cmd = perl $(srctree)/scripts/sign-file \ $(CONFIG_MODULE_SIG_HASH) $(MODSECKEY) $(MODPUBKEY)
Of course I could disable signed modules while building a new kernel, but I was in it for the ride (I had better ones) ;-)
Gr. AvS
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