[PATCH 2/2] Fix kexec forbidding kernels signed with keys in the secondary keyring to boot

From: David Howells
Date: Thu Aug 16 2018 - 09:05:31 EST


From: Yannik Sembritzki <yannik@xxxxxxxxxxxxx>

The split of .system_keyring into .builtin_trusted_keys and
.secondary_trusted_keys broke kexec, thereby preventing kernels signed by
keys which are now in the secondary keyring from being kexec'd.

Fix this by passing VERIFY_USE_SECONDARY_KEYRING to
verify_pefile_signature().

Fixes: d3bfe84129f6 ("certs: Add a secondary system keyring that can be added to dynamically")
Signed-off-by: Yannik Sembritzki <yannik@xxxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: kexec@xxxxxxxxxxxxxxxxxxx
cc: keyrings@xxxxxxxxxxxxxxx
cc: linux-security-module@xxxxxxxxxxxxxxx
cc: stable@xxxxxxxxxxxxxxx
---

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 7326078eaa7a..278cd07228dd 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,
+ VERIFY_USE_SECONDARY_KEYRING,
VERIFYING_KEXEC_PE_SIGNATURE);
}
#endif