From mboxrd@z Thu Jan 1 00:00:00 1970 From: zohar@linux.vnet.ibm.com (Mimi Zohar) Date: Thu, 06 Apr 2017 23:49:10 -0400 Subject: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set In-Reply-To: <20170407030545.GA4296@dhcp-128-65.nay.redhat.com> References: <149142326734.5101.4596394505987813763.stgit@warthog.procyon.org.uk> <149142335441.5101.2294976563846442575.stgit@warthog.procyon.org.uk> <20170407030545.GA4296@dhcp-128-65.nay.redhat.com> Message-ID: <1491536950.4184.10.camel@linux.vnet.ibm.com> To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org On Fri, 2017-04-07 at 11:05 +0800, Dave Young wrote: > On 04/05/17 at 09:15pm, David Howells wrote: > > From: Chun-Yi Lee > > > > When KEXEC_VERIFY_SIG is not enabled, kernel should not loads image > > through kexec_file systemcall if securelevel has been set. > > > > This code was showed in Matthew's patch but not in git: > > https://lkml.org/lkml/2015/3/13/778 > > > > Cc: Matthew Garrett > > Signed-off-by: Chun-Yi Lee > > Signed-off-by: David Howells > > cc: kexec at lists.infradead.org > > --- > > > > kernel/kexec_file.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c > > index b118735fea9d..f6937eecd1eb 100644 > > --- a/kernel/kexec_file.c > > +++ b/kernel/kexec_file.c > > @@ -268,6 +268,12 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, > > if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) > > return -EPERM; > > > > + /* Don't permit images to be loaded into trusted kernels if we're not > > + * going to verify the signature on them > > + */ > > + if (!IS_ENABLED(CONFIG_KEXEC_VERIFY_SIG) && kernel_is_locked_down()) > > + return -EPERM; > > + > > IMA can be used to verify file signatures too, based on the LSM hooks in ?kernel_read_file_from_fd(). ?CONFIG_KEXEC_VERIFY_SIG should not be required. Mimi > /* Make sure we have a legal set of flags */ > > if (flags != (flags & KEXEC_FILE_FLAGS)) > > return -EINVAL; > > > > > > _______________________________________________ > > kexec mailing list > > kexec at lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/kexec > > Acked-by: Dave Young > > Thanks > Dave > -- > To unsubscribe from this list: send the line "unsubscribe linux-security-module" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html