From 29d3c1c8dfe752c01b7115ecd5a3142b232a38e1 Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Mon, 19 Aug 2019 17:18:01 -0700 Subject: kexec: Allow kexec_file() with appropriate IMA policy when locked down Systems in lockdown mode should block the kexec of untrusted kernels. For x86 and ARM we can ensure that a kernel is trustworthy by validating a PE signature, but this isn't possible on other architectures. On those platforms we can use IMA digital signatures instead. Add a function to determine whether IMA has or will verify signatures for a given event type, and if so permit kexec_file() even if the kernel is otherwise locked down. This is restricted to cases where CONFIG_INTEGRITY_TRUSTED_KEYRING is set in order to prevent an attacker from loading additional keys at runtime. Signed-off-by: Matthew Garrett Acked-by: Mimi Zohar Cc: Dmitry Kasatkin Cc: linux-integrity@vger.kernel.org Signed-off-by: James Morris --- security/integrity/ima/ima.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'security/integrity/ima/ima.h') diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index ca10917b5f89..874bd77d3b91 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -111,6 +111,8 @@ struct ima_kexec_hdr { u64 count; }; +extern const int read_idmap[]; + #ifdef CONFIG_HAVE_IMA_KEXEC void ima_load_kexec_buffer(void); #else -- cgit v1.2.3