Messages in this thread | | | Date | Thu, 16 Aug 2018 08:52:06 +0800 | From | Dave Young <> | Subject | Re: [PATCH] Fix kexec forbidding kernels signed with custom platform keys to boot |
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On 08/15/18 at 01:42pm, Vivek Goyal wrote: > On Wed, Aug 15, 2018 at 07:27:33PM +0200, Yannik Sembritzki wrote: > > Would this be okay? > > [ CC dave young, Baoquan, Justin Forbes] > > Hi Yannik, > > I am reading that bug and wondering that what broke it. It used to work, > so some change broke it. > > Justin said that we have been signing fedora kernels with fedora keys so > looks like no change there. > > Previously, I think all the keys used to go in system keyring and it > used to work. Is it somehow because of split in builtin keyring and > secondary system keyring. Could it be that fedora key used to show > up in system keyring previously and it worked but now it shows up > in secondary system keyring and by default we don't use keys from > that keyring for signature verification?
There was a Fedora bug below: https://bugzilla.redhat.com/show_bug.cgi?id=1470995
I posted a fix here but bobody responsed, I think I obviously did not consider the "trust build system only" point from Linus: http://lists.infradead.org/pipermail/kexec/2017-November/019632.html
But either above patch or defining a macro for the "1UL" in cert header file works.
Since nobody reviewed my patch so later I submitted a Fedora only patch which is similar with Yannik's and merged in Fedora tree: https://bugzilla.redhat.com/attachment.cgi?id=1450772&action=edit
> > Thanks > Vivek > > > > > diff --git a/arch/x86/kernel/kexec-bzimage64.c > > b/arch/x86/kernel/kexec-bzimage64.c > > index 7326078e..2ba47e24 100644 > > --- a/arch/x86/kernel/kexec-bzimage64.c > > +++ b/arch/x86/kernel/kexec-bzimage64.c > > @@ -41,6 +41,9 @@ > > #define MIN_KERNEL_LOAD_ADDR 0x100000 > > #define MIN_INITRD_LOAD_ADDR 0x1000000 > > > > +// Allow both builtin trusted keys and secondary trusted keys > > +#define TRUST_FULL_KEYRING (void *)1UL > > + > > /* > > * This is a place holder for all boot loader specific data structure which > > * gets allocated in one call but gets freed much later during cleanup > > @@ -532,7 +535,7 @@ static int bzImage64_cleanup(void *loader_data) > > static int bzImage64_verify_sig(const char *kernel, unsigned long > > kernel_len) > > { > > return verify_pefile_signature(kernel, kernel_len, > > - NULL, > > + TRUST_FULL_KEYRING, > > VERIFYING_KEXEC_PE_SIGNATURE); > > } > > #endif > > -- > > > > On 15.08.2018 18:54, Linus Torvalds wrote: > > > This needs more people involved, and at least a sign-off. > > > > > > It looks ok, but I think we need a #define for the magical (void *)1UL > > > thing. I see the use in verify_pkcs7_signature(), but still. > > > > > > Linus > > > > > > > > > > > > On Wed, Aug 15, 2018 at 3:11 AM Yannik Sembritzki <yannik@sembritzki.me> wrote: > > >> --- > > >> arch/x86/kernel/kexec-bzimage64.c | 2 +- > > >> 1 file changed, 1 insertion(+), 1 deletion(-) > > >> > > >> diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c > > >> index 7326078e..eaaa125d 100644 > > >> --- a/arch/x86/kernel/kexec-bzimage64.c > > >> +++ b/arch/x86/kernel/kexec-bzimage64.c > > >> @@ -532,7 +532,7 @@ static int bzImage64_cleanup(void *loader_data) > > >> static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len) > > >> { > > >> return verify_pefile_signature(kernel, kernel_len, > > >> - NULL, > > >> + (void *)1UL, > > >> VERIFYING_KEXEC_PE_SIGNATURE); > > >> } > > >> #endif > > >> -- > > >> 2.17.1 > > >> > > >> The exact scenario under which this issue occurs is described here: > > >> https://bugzilla.redhat.com/show_bug.cgi?id=1554113 > > >> > >
Thanks Dave
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