The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0d519cadf75184a24313568e7f489a7fc9b1be3b Mon Sep 17 00:00:00 2001 From: Coiby Xu coxu@redhat.com Date: Thu, 14 Jul 2022 21:40:26 +0800 Subject: [PATCH] arm64: kexec_file: use more system keyrings to verify kernel image signature
Currently, when loading a kernel image via the kexec_file_load() system call, arm64 can only use the .builtin_trusted_keys keyring to verify a signature whereas x86 can use three more keyrings i.e. .secondary_trusted_keys, .machine and .platform keyrings. For example, one resulting problem is kexec'ing a kernel image would be rejected with the error "Lockdown: kexec: kexec of unsigned images is restricted; see man kernel_lockdown.7".
This patch set enables arm64 to make use of the same keyrings as x86 to verify the signature kexec'ed kernel image.
Fixes: 732b7b93d849 ("arm64: kexec_file: add kernel signature verification support") Cc: stable@vger.kernel.org # 105e10e2cf1c: kexec_file: drop weak attribute from functions Cc: stable@vger.kernel.org # 34d5960af253: kexec: clean up arch_kexec_kernel_verify_sig Cc: stable@vger.kernel.org # 83b7bb2d49ae: kexec, KEYS: make the code in bzImage64_verify_sig generic Acked-by: Baoquan He bhe@redhat.com Cc: kexec@lists.infradead.org Cc: keyrings@vger.kernel.org Cc: linux-security-module@vger.kernel.org Co-developed-by: Michal Suchanek msuchanek@suse.de Signed-off-by: Michal Suchanek msuchanek@suse.de Acked-by: Will Deacon will@kernel.org Signed-off-by: Coiby Xu coxu@redhat.com Signed-off-by: Mimi Zohar zohar@linux.ibm.com
diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c index 9ec34690e255..5ed6a585f21f 100644 --- a/arch/arm64/kernel/kexec_image.c +++ b/arch/arm64/kernel/kexec_image.c @@ -14,7 +14,6 @@ #include <linux/kexec.h> #include <linux/pe.h> #include <linux/string.h> -#include <linux/verification.h> #include <asm/byteorder.h> #include <asm/cpufeature.h> #include <asm/image.h> @@ -130,18 +129,10 @@ static void *image_load(struct kimage *image, return NULL; }
-#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG -static int image_verify_sig(const char *kernel, unsigned long kernel_len) -{ - return verify_pefile_signature(kernel, kernel_len, NULL, - VERIFYING_KEXEC_PE_SIGNATURE); -} -#endif - const struct kexec_file_ops kexec_image_ops = { .probe = image_probe, .load = image_load, #ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG - .verify_sig = image_verify_sig, + .verify_sig = kexec_kernel_verify_pe_sig, #endif };