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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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0d519cadf7
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: 732b7b93d8 ("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>
138 lines
3.7 KiB
C
138 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Kexec image loader
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* Copyright (C) 2018 Linaro Limited
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* Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
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*/
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#define pr_fmt(fmt) "kexec_file(Image): " fmt
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#include <linux/err.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/kexec.h>
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#include <linux/pe.h>
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#include <linux/string.h>
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#include <asm/byteorder.h>
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#include <asm/cpufeature.h>
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#include <asm/image.h>
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#include <asm/memory.h>
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static int image_probe(const char *kernel_buf, unsigned long kernel_len)
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{
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const struct arm64_image_header *h =
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(const struct arm64_image_header *)(kernel_buf);
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if (!h || (kernel_len < sizeof(*h)))
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return -EINVAL;
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if (memcmp(&h->magic, ARM64_IMAGE_MAGIC, sizeof(h->magic)))
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return -EINVAL;
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return 0;
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}
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static void *image_load(struct kimage *image,
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char *kernel, unsigned long kernel_len,
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char *initrd, unsigned long initrd_len,
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char *cmdline, unsigned long cmdline_len)
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{
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struct arm64_image_header *h;
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u64 flags, value;
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bool be_image, be_kernel;
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struct kexec_buf kbuf;
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unsigned long text_offset, kernel_segment_number;
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struct kexec_segment *kernel_segment;
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int ret;
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/*
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* We require a kernel with an unambiguous Image header. Per
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* Documentation/arm64/booting.rst, this is the case when image_size
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* is non-zero (practically speaking, since v3.17).
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*/
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h = (struct arm64_image_header *)kernel;
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if (!h->image_size)
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return ERR_PTR(-EINVAL);
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/* Check cpu features */
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flags = le64_to_cpu(h->flags);
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be_image = arm64_image_flag_field(flags, ARM64_IMAGE_FLAG_BE);
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be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
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if ((be_image != be_kernel) && !system_supports_mixed_endian())
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return ERR_PTR(-EINVAL);
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value = arm64_image_flag_field(flags, ARM64_IMAGE_FLAG_PAGE_SIZE);
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if (((value == ARM64_IMAGE_FLAG_PAGE_SIZE_4K) &&
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!system_supports_4kb_granule()) ||
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((value == ARM64_IMAGE_FLAG_PAGE_SIZE_64K) &&
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!system_supports_64kb_granule()) ||
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((value == ARM64_IMAGE_FLAG_PAGE_SIZE_16K) &&
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!system_supports_16kb_granule()))
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return ERR_PTR(-EINVAL);
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/* Load the kernel */
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kbuf.image = image;
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kbuf.buf_min = 0;
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kbuf.buf_max = ULONG_MAX;
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kbuf.top_down = false;
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kbuf.buffer = kernel;
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kbuf.bufsz = kernel_len;
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kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
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kbuf.memsz = le64_to_cpu(h->image_size);
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text_offset = le64_to_cpu(h->text_offset);
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kbuf.buf_align = MIN_KIMG_ALIGN;
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/* Adjust kernel segment with TEXT_OFFSET */
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kbuf.memsz += text_offset;
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kernel_segment_number = image->nr_segments;
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/*
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* The location of the kernel segment may make it impossible to satisfy
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* the other segment requirements, so we try repeatedly to find a
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* location that will work.
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*/
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while ((ret = kexec_add_buffer(&kbuf)) == 0) {
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/* Try to load additional data */
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kernel_segment = &image->segment[kernel_segment_number];
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ret = load_other_segments(image, kernel_segment->mem,
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kernel_segment->memsz, initrd,
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initrd_len, cmdline);
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if (!ret)
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break;
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/*
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* We couldn't find space for the other segments; erase the
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* kernel segment and try the next available hole.
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*/
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image->nr_segments -= 1;
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kbuf.buf_min = kernel_segment->mem + kernel_segment->memsz;
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kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
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}
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if (ret) {
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pr_err("Could not find any suitable kernel location!");
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return ERR_PTR(ret);
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}
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kernel_segment = &image->segment[kernel_segment_number];
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kernel_segment->mem += text_offset;
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kernel_segment->memsz -= text_offset;
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image->start = kernel_segment->mem;
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pr_debug("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
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kernel_segment->mem, kbuf.bufsz,
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kernel_segment->memsz);
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return NULL;
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}
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const struct kexec_file_ops kexec_image_ops = {
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.probe = image_probe,
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.load = image_load,
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#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG
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.verify_sig = kexec_kernel_verify_pe_sig,
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#endif
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};
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