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-----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQQdXVVFGN5XqKr1Hj7LwZzRsCrn5QUCZO0WoxQcem9oYXJAbGlu dXguaWJtLmNvbQAKCRDLwZzRsCrn5alsAP0UZQIKI2zEjFdtucgClcSouflIOC5i Hvtgv3qVFXPZQwEA2H/SGjigtH5NruVXECDZdrIfaGGvBhyeY72lbswXfQ0= =Gu8i -----END PGP SIGNATURE----- Merge tag 'integrity-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull integrity subsystem updates from Mimi Zohar: - With commit099f26f22f
("integrity: machine keyring CA configuration") certificates may be loaded onto the IMA keyring, directly or indirectly signed by keys on either the "builtin" or the "machine" keyrings. With the ability for the system/machine owner to sign the IMA policy itself without needing to recompile the kernel, update the IMA architecture specific policy rules to require the IMA policy itself be signed. [ As commit099f26f22f
was upstreamed in linux-6.4, updating the IMA architecture specific policy now to require signed IMA policies may break userspace expectations. ] - IMA only checked the file data hash was not on the system blacklist keyring for files with an appended signature (e.g. kernel modules, Power kernel image). Check all file data hashes regardless of how it was signed - Code cleanup, and a kernel-doc update * tag 'integrity-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: kexec_lock: Replace kexec_mutex() by kexec_lock() in two comments ima: require signed IMA policy when UEFI secure boot is enabled integrity: Always reference the blacklist keyring with appraisal ima: Remove deprecated IMA_TRUSTED_KEYRING Kconfig
1159 lines
28 KiB
C
1159 lines
28 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* kexec: kexec_file_load system call
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*
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* Copyright (C) 2014 Red Hat Inc.
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* Authors:
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* Vivek Goyal <vgoyal@redhat.com>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/capability.h>
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#include <linux/mm.h>
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#include <linux/file.h>
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#include <linux/slab.h>
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#include <linux/kexec.h>
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#include <linux/memblock.h>
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#include <linux/mutex.h>
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#include <linux/list.h>
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#include <linux/fs.h>
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#include <linux/ima.h>
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#include <crypto/hash.h>
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#include <crypto/sha2.h>
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#include <linux/elf.h>
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#include <linux/elfcore.h>
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#include <linux/kernel.h>
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#include <linux/kernel_read_file.h>
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#include <linux/syscalls.h>
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#include <linux/vmalloc.h>
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#include "kexec_internal.h"
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#ifdef CONFIG_KEXEC_SIG
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static bool sig_enforce = IS_ENABLED(CONFIG_KEXEC_SIG_FORCE);
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void set_kexec_sig_enforced(void)
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{
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sig_enforce = true;
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}
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#endif
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static int kexec_calculate_store_digests(struct kimage *image);
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/* Maximum size in bytes for kernel/initrd files. */
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#define KEXEC_FILE_SIZE_MAX min_t(s64, 4LL << 30, SSIZE_MAX)
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/*
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* Currently this is the only default function that is exported as some
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* architectures need it to do additional handlings.
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* In the future, other default functions may be exported too if required.
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*/
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int kexec_image_probe_default(struct kimage *image, void *buf,
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unsigned long buf_len)
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{
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const struct kexec_file_ops * const *fops;
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int ret = -ENOEXEC;
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for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
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ret = (*fops)->probe(buf, buf_len);
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if (!ret) {
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image->fops = *fops;
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return ret;
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}
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}
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return ret;
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}
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static void *kexec_image_load_default(struct kimage *image)
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{
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if (!image->fops || !image->fops->load)
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return ERR_PTR(-ENOEXEC);
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return image->fops->load(image, image->kernel_buf,
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image->kernel_buf_len, image->initrd_buf,
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image->initrd_buf_len, image->cmdline_buf,
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image->cmdline_buf_len);
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}
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int kexec_image_post_load_cleanup_default(struct kimage *image)
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{
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if (!image->fops || !image->fops->cleanup)
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return 0;
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return image->fops->cleanup(image->image_loader_data);
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}
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/*
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* Free up memory used by kernel, initrd, and command line. This is temporary
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* memory allocation which is not needed any more after these buffers have
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* been loaded into separate segments and have been copied elsewhere.
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*/
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void kimage_file_post_load_cleanup(struct kimage *image)
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{
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struct purgatory_info *pi = &image->purgatory_info;
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vfree(image->kernel_buf);
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image->kernel_buf = NULL;
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vfree(image->initrd_buf);
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image->initrd_buf = NULL;
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kfree(image->cmdline_buf);
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image->cmdline_buf = NULL;
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vfree(pi->purgatory_buf);
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pi->purgatory_buf = NULL;
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vfree(pi->sechdrs);
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pi->sechdrs = NULL;
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#ifdef CONFIG_IMA_KEXEC
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vfree(image->ima_buffer);
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image->ima_buffer = NULL;
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#endif /* CONFIG_IMA_KEXEC */
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/* See if architecture has anything to cleanup post load */
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arch_kimage_file_post_load_cleanup(image);
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/*
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* Above call should have called into bootloader to free up
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* any data stored in kimage->image_loader_data. It should
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* be ok now to free it up.
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*/
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kfree(image->image_loader_data);
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image->image_loader_data = NULL;
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}
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#ifdef CONFIG_KEXEC_SIG
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#ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
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int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len)
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{
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int ret;
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ret = verify_pefile_signature(kernel, kernel_len,
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VERIFY_USE_SECONDARY_KEYRING,
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VERIFYING_KEXEC_PE_SIGNATURE);
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if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) {
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ret = verify_pefile_signature(kernel, kernel_len,
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VERIFY_USE_PLATFORM_KEYRING,
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VERIFYING_KEXEC_PE_SIGNATURE);
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}
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return ret;
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}
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#endif
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static int kexec_image_verify_sig(struct kimage *image, void *buf,
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unsigned long buf_len)
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{
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if (!image->fops || !image->fops->verify_sig) {
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pr_debug("kernel loader does not support signature verification.\n");
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return -EKEYREJECTED;
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}
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return image->fops->verify_sig(buf, buf_len);
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}
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static int
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kimage_validate_signature(struct kimage *image)
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{
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int ret;
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ret = kexec_image_verify_sig(image, image->kernel_buf,
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image->kernel_buf_len);
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if (ret) {
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if (sig_enforce) {
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pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
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return ret;
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}
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/*
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* If IMA is guaranteed to appraise a signature on the kexec
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* image, permit it even if the kernel is otherwise locked
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* down.
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*/
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if (!ima_appraise_signature(READING_KEXEC_IMAGE) &&
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security_locked_down(LOCKDOWN_KEXEC))
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return -EPERM;
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pr_debug("kernel signature verification failed (%d).\n", ret);
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}
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return 0;
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}
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#endif
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/*
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* In file mode list of segments is prepared by kernel. Copy relevant
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* data from user space, do error checking, prepare segment list
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*/
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static int
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kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
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const char __user *cmdline_ptr,
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unsigned long cmdline_len, unsigned flags)
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{
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ssize_t ret;
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void *ldata;
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ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
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KEXEC_FILE_SIZE_MAX, NULL,
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READING_KEXEC_IMAGE);
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if (ret < 0)
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return ret;
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image->kernel_buf_len = ret;
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/* Call arch image probe handlers */
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ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
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image->kernel_buf_len);
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if (ret)
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goto out;
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#ifdef CONFIG_KEXEC_SIG
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ret = kimage_validate_signature(image);
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if (ret)
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goto out;
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#endif
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/* It is possible that there no initramfs is being loaded */
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if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
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ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
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KEXEC_FILE_SIZE_MAX, NULL,
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READING_KEXEC_INITRAMFS);
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if (ret < 0)
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goto out;
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image->initrd_buf_len = ret;
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ret = 0;
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}
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if (cmdline_len) {
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image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
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if (IS_ERR(image->cmdline_buf)) {
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ret = PTR_ERR(image->cmdline_buf);
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image->cmdline_buf = NULL;
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goto out;
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}
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image->cmdline_buf_len = cmdline_len;
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/* command line should be a string with last byte null */
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if (image->cmdline_buf[cmdline_len - 1] != '\0') {
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ret = -EINVAL;
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goto out;
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}
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ima_kexec_cmdline(kernel_fd, image->cmdline_buf,
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image->cmdline_buf_len - 1);
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}
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/* IMA needs to pass the measurement list to the next kernel. */
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ima_add_kexec_buffer(image);
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/* Call image load handler */
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ldata = kexec_image_load_default(image);
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if (IS_ERR(ldata)) {
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ret = PTR_ERR(ldata);
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goto out;
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}
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image->image_loader_data = ldata;
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out:
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/* In case of error, free up all allocated memory in this function */
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if (ret)
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kimage_file_post_load_cleanup(image);
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return ret;
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}
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static int
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kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
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int initrd_fd, const char __user *cmdline_ptr,
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unsigned long cmdline_len, unsigned long flags)
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{
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int ret;
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struct kimage *image;
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bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
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image = do_kimage_alloc_init();
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if (!image)
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return -ENOMEM;
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image->file_mode = 1;
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if (kexec_on_panic) {
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/* Enable special crash kernel control page alloc policy. */
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image->control_page = crashk_res.start;
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image->type = KEXEC_TYPE_CRASH;
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}
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ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
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cmdline_ptr, cmdline_len, flags);
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if (ret)
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goto out_free_image;
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ret = sanity_check_segment_list(image);
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if (ret)
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goto out_free_post_load_bufs;
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ret = -ENOMEM;
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image->control_code_page = kimage_alloc_control_pages(image,
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get_order(KEXEC_CONTROL_PAGE_SIZE));
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if (!image->control_code_page) {
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pr_err("Could not allocate control_code_buffer\n");
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goto out_free_post_load_bufs;
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}
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if (!kexec_on_panic) {
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image->swap_page = kimage_alloc_control_pages(image, 0);
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if (!image->swap_page) {
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pr_err("Could not allocate swap buffer\n");
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goto out_free_control_pages;
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}
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}
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*rimage = image;
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return 0;
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out_free_control_pages:
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kimage_free_page_list(&image->control_pages);
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out_free_post_load_bufs:
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kimage_file_post_load_cleanup(image);
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out_free_image:
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kfree(image);
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return ret;
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}
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SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
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unsigned long, cmdline_len, const char __user *, cmdline_ptr,
|
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unsigned long, flags)
|
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{
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int image_type = (flags & KEXEC_FILE_ON_CRASH) ?
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KEXEC_TYPE_CRASH : KEXEC_TYPE_DEFAULT;
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struct kimage **dest_image, *image;
|
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int ret = 0, i;
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|
|
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/* We only trust the superuser with rebooting the system. */
|
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if (!kexec_load_permitted(image_type))
|
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return -EPERM;
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|
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/* Make sure we have a legal set of flags */
|
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if (flags != (flags & KEXEC_FILE_FLAGS))
|
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return -EINVAL;
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|
|
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image = NULL;
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|
|
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if (!kexec_trylock())
|
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return -EBUSY;
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|
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if (image_type == KEXEC_TYPE_CRASH) {
|
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dest_image = &kexec_crash_image;
|
|
if (kexec_crash_image)
|
|
arch_kexec_unprotect_crashkres();
|
|
} else {
|
|
dest_image = &kexec_image;
|
|
}
|
|
|
|
if (flags & KEXEC_FILE_UNLOAD)
|
|
goto exchange;
|
|
|
|
/*
|
|
* In case of crash, new kernel gets loaded in reserved region. It is
|
|
* same memory where old crash kernel might be loaded. Free any
|
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* current crash dump kernel before we corrupt it.
|
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*/
|
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if (flags & KEXEC_FILE_ON_CRASH)
|
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kimage_free(xchg(&kexec_crash_image, NULL));
|
|
|
|
ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
|
|
cmdline_len, flags);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = machine_kexec_prepare(image);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/*
|
|
* Some architecture(like S390) may touch the crash memory before
|
|
* machine_kexec_prepare(), we must copy vmcoreinfo data after it.
|
|
*/
|
|
ret = kimage_crash_copy_vmcoreinfo(image);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = kexec_calculate_store_digests(image);
|
|
if (ret)
|
|
goto out;
|
|
|
|
for (i = 0; i < image->nr_segments; i++) {
|
|
struct kexec_segment *ksegment;
|
|
|
|
ksegment = &image->segment[i];
|
|
pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
|
|
i, ksegment->buf, ksegment->bufsz, ksegment->mem,
|
|
ksegment->memsz);
|
|
|
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ret = kimage_load_segment(image, &image->segment[i]);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
|
|
kimage_terminate(image);
|
|
|
|
ret = machine_kexec_post_load(image);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/*
|
|
* Free up any temporary buffers allocated which are not needed
|
|
* after image has been loaded
|
|
*/
|
|
kimage_file_post_load_cleanup(image);
|
|
exchange:
|
|
image = xchg(dest_image, image);
|
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out:
|
|
if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
|
|
arch_kexec_protect_crashkres();
|
|
|
|
kexec_unlock();
|
|
kimage_free(image);
|
|
return ret;
|
|
}
|
|
|
|
static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
|
|
struct kexec_buf *kbuf)
|
|
{
|
|
struct kimage *image = kbuf->image;
|
|
unsigned long temp_start, temp_end;
|
|
|
|
temp_end = min(end, kbuf->buf_max);
|
|
temp_start = temp_end - kbuf->memsz;
|
|
|
|
do {
|
|
/* align down start */
|
|
temp_start = temp_start & (~(kbuf->buf_align - 1));
|
|
|
|
if (temp_start < start || temp_start < kbuf->buf_min)
|
|
return 0;
|
|
|
|
temp_end = temp_start + kbuf->memsz - 1;
|
|
|
|
/*
|
|
* Make sure this does not conflict with any of existing
|
|
* segments
|
|
*/
|
|
if (kimage_is_destination_range(image, temp_start, temp_end)) {
|
|
temp_start = temp_start - PAGE_SIZE;
|
|
continue;
|
|
}
|
|
|
|
/* We found a suitable memory range */
|
|
break;
|
|
} while (1);
|
|
|
|
/* If we are here, we found a suitable memory range */
|
|
kbuf->mem = temp_start;
|
|
|
|
/* Success, stop navigating through remaining System RAM ranges */
|
|
return 1;
|
|
}
|
|
|
|
static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
|
|
struct kexec_buf *kbuf)
|
|
{
|
|
struct kimage *image = kbuf->image;
|
|
unsigned long temp_start, temp_end;
|
|
|
|
temp_start = max(start, kbuf->buf_min);
|
|
|
|
do {
|
|
temp_start = ALIGN(temp_start, kbuf->buf_align);
|
|
temp_end = temp_start + kbuf->memsz - 1;
|
|
|
|
if (temp_end > end || temp_end > kbuf->buf_max)
|
|
return 0;
|
|
/*
|
|
* Make sure this does not conflict with any of existing
|
|
* segments
|
|
*/
|
|
if (kimage_is_destination_range(image, temp_start, temp_end)) {
|
|
temp_start = temp_start + PAGE_SIZE;
|
|
continue;
|
|
}
|
|
|
|
/* We found a suitable memory range */
|
|
break;
|
|
} while (1);
|
|
|
|
/* If we are here, we found a suitable memory range */
|
|
kbuf->mem = temp_start;
|
|
|
|
/* Success, stop navigating through remaining System RAM ranges */
|
|
return 1;
|
|
}
|
|
|
|
static int locate_mem_hole_callback(struct resource *res, void *arg)
|
|
{
|
|
struct kexec_buf *kbuf = (struct kexec_buf *)arg;
|
|
u64 start = res->start, end = res->end;
|
|
unsigned long sz = end - start + 1;
|
|
|
|
/* Returning 0 will take to next memory range */
|
|
|
|
/* Don't use memory that will be detected and handled by a driver. */
|
|
if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED)
|
|
return 0;
|
|
|
|
if (sz < kbuf->memsz)
|
|
return 0;
|
|
|
|
if (end < kbuf->buf_min || start > kbuf->buf_max)
|
|
return 0;
|
|
|
|
/*
|
|
* Allocate memory top down with-in ram range. Otherwise bottom up
|
|
* allocation.
|
|
*/
|
|
if (kbuf->top_down)
|
|
return locate_mem_hole_top_down(start, end, kbuf);
|
|
return locate_mem_hole_bottom_up(start, end, kbuf);
|
|
}
|
|
|
|
#ifdef CONFIG_ARCH_KEEP_MEMBLOCK
|
|
static int kexec_walk_memblock(struct kexec_buf *kbuf,
|
|
int (*func)(struct resource *, void *))
|
|
{
|
|
int ret = 0;
|
|
u64 i;
|
|
phys_addr_t mstart, mend;
|
|
struct resource res = { };
|
|
|
|
if (kbuf->image->type == KEXEC_TYPE_CRASH)
|
|
return func(&crashk_res, kbuf);
|
|
|
|
/*
|
|
* Using MEMBLOCK_NONE will properly skip MEMBLOCK_DRIVER_MANAGED. See
|
|
* IORESOURCE_SYSRAM_DRIVER_MANAGED handling in
|
|
* locate_mem_hole_callback().
|
|
*/
|
|
if (kbuf->top_down) {
|
|
for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
|
|
&mstart, &mend, NULL) {
|
|
/*
|
|
* In memblock, end points to the first byte after the
|
|
* range while in kexec, end points to the last byte
|
|
* in the range.
|
|
*/
|
|
res.start = mstart;
|
|
res.end = mend - 1;
|
|
ret = func(&res, kbuf);
|
|
if (ret)
|
|
break;
|
|
}
|
|
} else {
|
|
for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
|
|
&mstart, &mend, NULL) {
|
|
/*
|
|
* In memblock, end points to the first byte after the
|
|
* range while in kexec, end points to the last byte
|
|
* in the range.
|
|
*/
|
|
res.start = mstart;
|
|
res.end = mend - 1;
|
|
ret = func(&res, kbuf);
|
|
if (ret)
|
|
break;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
#else
|
|
static int kexec_walk_memblock(struct kexec_buf *kbuf,
|
|
int (*func)(struct resource *, void *))
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* kexec_walk_resources - call func(data) on free memory regions
|
|
* @kbuf: Context info for the search. Also passed to @func.
|
|
* @func: Function to call for each memory region.
|
|
*
|
|
* Return: The memory walk will stop when func returns a non-zero value
|
|
* and that value will be returned. If all free regions are visited without
|
|
* func returning non-zero, then zero will be returned.
|
|
*/
|
|
static int kexec_walk_resources(struct kexec_buf *kbuf,
|
|
int (*func)(struct resource *, void *))
|
|
{
|
|
if (kbuf->image->type == KEXEC_TYPE_CRASH)
|
|
return walk_iomem_res_desc(crashk_res.desc,
|
|
IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
|
|
crashk_res.start, crashk_res.end,
|
|
kbuf, func);
|
|
else
|
|
return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
|
|
}
|
|
|
|
/**
|
|
* kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
|
|
* @kbuf: Parameters for the memory search.
|
|
*
|
|
* On success, kbuf->mem will have the start address of the memory region found.
|
|
*
|
|
* Return: 0 on success, negative errno on error.
|
|
*/
|
|
int kexec_locate_mem_hole(struct kexec_buf *kbuf)
|
|
{
|
|
int ret;
|
|
|
|
/* Arch knows where to place */
|
|
if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
|
|
return 0;
|
|
|
|
if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
|
|
ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
|
|
else
|
|
ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
|
|
|
|
return ret == 1 ? 0 : -EADDRNOTAVAIL;
|
|
}
|
|
|
|
/**
|
|
* kexec_add_buffer - place a buffer in a kexec segment
|
|
* @kbuf: Buffer contents and memory parameters.
|
|
*
|
|
* This function assumes that kexec_lock is held.
|
|
* On successful return, @kbuf->mem will have the physical address of
|
|
* the buffer in memory.
|
|
*
|
|
* Return: 0 on success, negative errno on error.
|
|
*/
|
|
int kexec_add_buffer(struct kexec_buf *kbuf)
|
|
{
|
|
struct kexec_segment *ksegment;
|
|
int ret;
|
|
|
|
/* Currently adding segment this way is allowed only in file mode */
|
|
if (!kbuf->image->file_mode)
|
|
return -EINVAL;
|
|
|
|
if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Make sure we are not trying to add buffer after allocating
|
|
* control pages. All segments need to be placed first before
|
|
* any control pages are allocated. As control page allocation
|
|
* logic goes through list of segments to make sure there are
|
|
* no destination overlaps.
|
|
*/
|
|
if (!list_empty(&kbuf->image->control_pages)) {
|
|
WARN_ON(1);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Ensure minimum alignment needed for segments. */
|
|
kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
|
|
kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
|
|
|
|
/* Walk the RAM ranges and allocate a suitable range for the buffer */
|
|
ret = arch_kexec_locate_mem_hole(kbuf);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Found a suitable memory range */
|
|
ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
|
|
ksegment->kbuf = kbuf->buffer;
|
|
ksegment->bufsz = kbuf->bufsz;
|
|
ksegment->mem = kbuf->mem;
|
|
ksegment->memsz = kbuf->memsz;
|
|
kbuf->image->nr_segments++;
|
|
return 0;
|
|
}
|
|
|
|
/* Calculate and store the digest of segments */
|
|
static int kexec_calculate_store_digests(struct kimage *image)
|
|
{
|
|
struct crypto_shash *tfm;
|
|
struct shash_desc *desc;
|
|
int ret = 0, i, j, zero_buf_sz, sha_region_sz;
|
|
size_t desc_size, nullsz;
|
|
char *digest;
|
|
void *zero_buf;
|
|
struct kexec_sha_region *sha_regions;
|
|
struct purgatory_info *pi = &image->purgatory_info;
|
|
|
|
if (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY))
|
|
return 0;
|
|
|
|
zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
|
|
zero_buf_sz = PAGE_SIZE;
|
|
|
|
tfm = crypto_alloc_shash("sha256", 0, 0);
|
|
if (IS_ERR(tfm)) {
|
|
ret = PTR_ERR(tfm);
|
|
goto out;
|
|
}
|
|
|
|
desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
|
|
desc = kzalloc(desc_size, GFP_KERNEL);
|
|
if (!desc) {
|
|
ret = -ENOMEM;
|
|
goto out_free_tfm;
|
|
}
|
|
|
|
sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
|
|
sha_regions = vzalloc(sha_region_sz);
|
|
if (!sha_regions) {
|
|
ret = -ENOMEM;
|
|
goto out_free_desc;
|
|
}
|
|
|
|
desc->tfm = tfm;
|
|
|
|
ret = crypto_shash_init(desc);
|
|
if (ret < 0)
|
|
goto out_free_sha_regions;
|
|
|
|
digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
|
|
if (!digest) {
|
|
ret = -ENOMEM;
|
|
goto out_free_sha_regions;
|
|
}
|
|
|
|
for (j = i = 0; i < image->nr_segments; i++) {
|
|
struct kexec_segment *ksegment;
|
|
|
|
#ifdef CONFIG_CRASH_HOTPLUG
|
|
/* Exclude elfcorehdr segment to allow future changes via hotplug */
|
|
if (j == image->elfcorehdr_index)
|
|
continue;
|
|
#endif
|
|
|
|
ksegment = &image->segment[i];
|
|
/*
|
|
* Skip purgatory as it will be modified once we put digest
|
|
* info in purgatory.
|
|
*/
|
|
if (ksegment->kbuf == pi->purgatory_buf)
|
|
continue;
|
|
|
|
ret = crypto_shash_update(desc, ksegment->kbuf,
|
|
ksegment->bufsz);
|
|
if (ret)
|
|
break;
|
|
|
|
/*
|
|
* Assume rest of the buffer is filled with zero and
|
|
* update digest accordingly.
|
|
*/
|
|
nullsz = ksegment->memsz - ksegment->bufsz;
|
|
while (nullsz) {
|
|
unsigned long bytes = nullsz;
|
|
|
|
if (bytes > zero_buf_sz)
|
|
bytes = zero_buf_sz;
|
|
ret = crypto_shash_update(desc, zero_buf, bytes);
|
|
if (ret)
|
|
break;
|
|
nullsz -= bytes;
|
|
}
|
|
|
|
if (ret)
|
|
break;
|
|
|
|
sha_regions[j].start = ksegment->mem;
|
|
sha_regions[j].len = ksegment->memsz;
|
|
j++;
|
|
}
|
|
|
|
if (!ret) {
|
|
ret = crypto_shash_final(desc, digest);
|
|
if (ret)
|
|
goto out_free_digest;
|
|
ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
|
|
sha_regions, sha_region_sz, 0);
|
|
if (ret)
|
|
goto out_free_digest;
|
|
|
|
ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
|
|
digest, SHA256_DIGEST_SIZE, 0);
|
|
if (ret)
|
|
goto out_free_digest;
|
|
}
|
|
|
|
out_free_digest:
|
|
kfree(digest);
|
|
out_free_sha_regions:
|
|
vfree(sha_regions);
|
|
out_free_desc:
|
|
kfree(desc);
|
|
out_free_tfm:
|
|
kfree(tfm);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY
|
|
/*
|
|
* kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
|
|
* @pi: Purgatory to be loaded.
|
|
* @kbuf: Buffer to setup.
|
|
*
|
|
* Allocates the memory needed for the buffer. Caller is responsible to free
|
|
* the memory after use.
|
|
*
|
|
* Return: 0 on success, negative errno on error.
|
|
*/
|
|
static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
|
|
struct kexec_buf *kbuf)
|
|
{
|
|
const Elf_Shdr *sechdrs;
|
|
unsigned long bss_align;
|
|
unsigned long bss_sz;
|
|
unsigned long align;
|
|
int i, ret;
|
|
|
|
sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
|
|
kbuf->buf_align = bss_align = 1;
|
|
kbuf->bufsz = bss_sz = 0;
|
|
|
|
for (i = 0; i < pi->ehdr->e_shnum; i++) {
|
|
if (!(sechdrs[i].sh_flags & SHF_ALLOC))
|
|
continue;
|
|
|
|
align = sechdrs[i].sh_addralign;
|
|
if (sechdrs[i].sh_type != SHT_NOBITS) {
|
|
if (kbuf->buf_align < align)
|
|
kbuf->buf_align = align;
|
|
kbuf->bufsz = ALIGN(kbuf->bufsz, align);
|
|
kbuf->bufsz += sechdrs[i].sh_size;
|
|
} else {
|
|
if (bss_align < align)
|
|
bss_align = align;
|
|
bss_sz = ALIGN(bss_sz, align);
|
|
bss_sz += sechdrs[i].sh_size;
|
|
}
|
|
}
|
|
kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
|
|
kbuf->memsz = kbuf->bufsz + bss_sz;
|
|
if (kbuf->buf_align < bss_align)
|
|
kbuf->buf_align = bss_align;
|
|
|
|
kbuf->buffer = vzalloc(kbuf->bufsz);
|
|
if (!kbuf->buffer)
|
|
return -ENOMEM;
|
|
pi->purgatory_buf = kbuf->buffer;
|
|
|
|
ret = kexec_add_buffer(kbuf);
|
|
if (ret)
|
|
goto out;
|
|
|
|
return 0;
|
|
out:
|
|
vfree(pi->purgatory_buf);
|
|
pi->purgatory_buf = NULL;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
|
|
* @pi: Purgatory to be loaded.
|
|
* @kbuf: Buffer prepared to store purgatory.
|
|
*
|
|
* Allocates the memory needed for the buffer. Caller is responsible to free
|
|
* the memory after use.
|
|
*
|
|
* Return: 0 on success, negative errno on error.
|
|
*/
|
|
static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
|
|
struct kexec_buf *kbuf)
|
|
{
|
|
unsigned long bss_addr;
|
|
unsigned long offset;
|
|
size_t sechdrs_size;
|
|
Elf_Shdr *sechdrs;
|
|
int i;
|
|
|
|
/*
|
|
* The section headers in kexec_purgatory are read-only. In order to
|
|
* have them modifiable make a temporary copy.
|
|
*/
|
|
sechdrs_size = array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum);
|
|
sechdrs = vzalloc(sechdrs_size);
|
|
if (!sechdrs)
|
|
return -ENOMEM;
|
|
memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff, sechdrs_size);
|
|
pi->sechdrs = sechdrs;
|
|
|
|
offset = 0;
|
|
bss_addr = kbuf->mem + kbuf->bufsz;
|
|
kbuf->image->start = pi->ehdr->e_entry;
|
|
|
|
for (i = 0; i < pi->ehdr->e_shnum; i++) {
|
|
unsigned long align;
|
|
void *src, *dst;
|
|
|
|
if (!(sechdrs[i].sh_flags & SHF_ALLOC))
|
|
continue;
|
|
|
|
align = sechdrs[i].sh_addralign;
|
|
if (sechdrs[i].sh_type == SHT_NOBITS) {
|
|
bss_addr = ALIGN(bss_addr, align);
|
|
sechdrs[i].sh_addr = bss_addr;
|
|
bss_addr += sechdrs[i].sh_size;
|
|
continue;
|
|
}
|
|
|
|
offset = ALIGN(offset, align);
|
|
|
|
/*
|
|
* Check if the segment contains the entry point, if so,
|
|
* calculate the value of image->start based on it.
|
|
* If the compiler has produced more than one .text section
|
|
* (Eg: .text.hot), they are generally after the main .text
|
|
* section, and they shall not be used to calculate
|
|
* image->start. So do not re-calculate image->start if it
|
|
* is not set to the initial value, and warn the user so they
|
|
* have a chance to fix their purgatory's linker script.
|
|
*/
|
|
if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
|
|
pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
|
|
pi->ehdr->e_entry < (sechdrs[i].sh_addr
|
|
+ sechdrs[i].sh_size) &&
|
|
!WARN_ON(kbuf->image->start != pi->ehdr->e_entry)) {
|
|
kbuf->image->start -= sechdrs[i].sh_addr;
|
|
kbuf->image->start += kbuf->mem + offset;
|
|
}
|
|
|
|
src = (void *)pi->ehdr + sechdrs[i].sh_offset;
|
|
dst = pi->purgatory_buf + offset;
|
|
memcpy(dst, src, sechdrs[i].sh_size);
|
|
|
|
sechdrs[i].sh_addr = kbuf->mem + offset;
|
|
sechdrs[i].sh_offset = offset;
|
|
offset += sechdrs[i].sh_size;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int kexec_apply_relocations(struct kimage *image)
|
|
{
|
|
int i, ret;
|
|
struct purgatory_info *pi = &image->purgatory_info;
|
|
const Elf_Shdr *sechdrs;
|
|
|
|
sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
|
|
|
|
for (i = 0; i < pi->ehdr->e_shnum; i++) {
|
|
const Elf_Shdr *relsec;
|
|
const Elf_Shdr *symtab;
|
|
Elf_Shdr *section;
|
|
|
|
relsec = sechdrs + i;
|
|
|
|
if (relsec->sh_type != SHT_RELA &&
|
|
relsec->sh_type != SHT_REL)
|
|
continue;
|
|
|
|
/*
|
|
* For section of type SHT_RELA/SHT_REL,
|
|
* ->sh_link contains section header index of associated
|
|
* symbol table. And ->sh_info contains section header
|
|
* index of section to which relocations apply.
|
|
*/
|
|
if (relsec->sh_info >= pi->ehdr->e_shnum ||
|
|
relsec->sh_link >= pi->ehdr->e_shnum)
|
|
return -ENOEXEC;
|
|
|
|
section = pi->sechdrs + relsec->sh_info;
|
|
symtab = sechdrs + relsec->sh_link;
|
|
|
|
if (!(section->sh_flags & SHF_ALLOC))
|
|
continue;
|
|
|
|
/*
|
|
* symtab->sh_link contain section header index of associated
|
|
* string table.
|
|
*/
|
|
if (symtab->sh_link >= pi->ehdr->e_shnum)
|
|
/* Invalid section number? */
|
|
continue;
|
|
|
|
/*
|
|
* Respective architecture needs to provide support for applying
|
|
* relocations of type SHT_RELA/SHT_REL.
|
|
*/
|
|
if (relsec->sh_type == SHT_RELA)
|
|
ret = arch_kexec_apply_relocations_add(pi, section,
|
|
relsec, symtab);
|
|
else if (relsec->sh_type == SHT_REL)
|
|
ret = arch_kexec_apply_relocations(pi, section,
|
|
relsec, symtab);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* kexec_load_purgatory - Load and relocate the purgatory object.
|
|
* @image: Image to add the purgatory to.
|
|
* @kbuf: Memory parameters to use.
|
|
*
|
|
* Allocates the memory needed for image->purgatory_info.sechdrs and
|
|
* image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
|
|
* to free the memory after use.
|
|
*
|
|
* Return: 0 on success, negative errno on error.
|
|
*/
|
|
int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
|
|
{
|
|
struct purgatory_info *pi = &image->purgatory_info;
|
|
int ret;
|
|
|
|
if (kexec_purgatory_size <= 0)
|
|
return -EINVAL;
|
|
|
|
pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
|
|
|
|
ret = kexec_purgatory_setup_kbuf(pi, kbuf);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
|
|
if (ret)
|
|
goto out_free_kbuf;
|
|
|
|
ret = kexec_apply_relocations(image);
|
|
if (ret)
|
|
goto out;
|
|
|
|
return 0;
|
|
out:
|
|
vfree(pi->sechdrs);
|
|
pi->sechdrs = NULL;
|
|
out_free_kbuf:
|
|
vfree(pi->purgatory_buf);
|
|
pi->purgatory_buf = NULL;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* kexec_purgatory_find_symbol - find a symbol in the purgatory
|
|
* @pi: Purgatory to search in.
|
|
* @name: Name of the symbol.
|
|
*
|
|
* Return: pointer to symbol in read-only symtab on success, NULL on error.
|
|
*/
|
|
static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
|
|
const char *name)
|
|
{
|
|
const Elf_Shdr *sechdrs;
|
|
const Elf_Ehdr *ehdr;
|
|
const Elf_Sym *syms;
|
|
const char *strtab;
|
|
int i, k;
|
|
|
|
if (!pi->ehdr)
|
|
return NULL;
|
|
|
|
ehdr = pi->ehdr;
|
|
sechdrs = (void *)ehdr + ehdr->e_shoff;
|
|
|
|
for (i = 0; i < ehdr->e_shnum; i++) {
|
|
if (sechdrs[i].sh_type != SHT_SYMTAB)
|
|
continue;
|
|
|
|
if (sechdrs[i].sh_link >= ehdr->e_shnum)
|
|
/* Invalid strtab section number */
|
|
continue;
|
|
strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
|
|
syms = (void *)ehdr + sechdrs[i].sh_offset;
|
|
|
|
/* Go through symbols for a match */
|
|
for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
|
|
if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
|
|
continue;
|
|
|
|
if (strcmp(strtab + syms[k].st_name, name) != 0)
|
|
continue;
|
|
|
|
if (syms[k].st_shndx == SHN_UNDEF ||
|
|
syms[k].st_shndx >= ehdr->e_shnum) {
|
|
pr_debug("Symbol: %s has bad section index %d.\n",
|
|
name, syms[k].st_shndx);
|
|
return NULL;
|
|
}
|
|
|
|
/* Found the symbol we are looking for */
|
|
return &syms[k];
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
|
|
{
|
|
struct purgatory_info *pi = &image->purgatory_info;
|
|
const Elf_Sym *sym;
|
|
Elf_Shdr *sechdr;
|
|
|
|
sym = kexec_purgatory_find_symbol(pi, name);
|
|
if (!sym)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
sechdr = &pi->sechdrs[sym->st_shndx];
|
|
|
|
/*
|
|
* Returns the address where symbol will finally be loaded after
|
|
* kexec_load_segment()
|
|
*/
|
|
return (void *)(sechdr->sh_addr + sym->st_value);
|
|
}
|
|
|
|
/*
|
|
* Get or set value of a symbol. If "get_value" is true, symbol value is
|
|
* returned in buf otherwise symbol value is set based on value in buf.
|
|
*/
|
|
int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
|
|
void *buf, unsigned int size, bool get_value)
|
|
{
|
|
struct purgatory_info *pi = &image->purgatory_info;
|
|
const Elf_Sym *sym;
|
|
Elf_Shdr *sec;
|
|
char *sym_buf;
|
|
|
|
sym = kexec_purgatory_find_symbol(pi, name);
|
|
if (!sym)
|
|
return -EINVAL;
|
|
|
|
if (sym->st_size != size) {
|
|
pr_err("symbol %s size mismatch: expected %lu actual %u\n",
|
|
name, (unsigned long)sym->st_size, size);
|
|
return -EINVAL;
|
|
}
|
|
|
|
sec = pi->sechdrs + sym->st_shndx;
|
|
|
|
if (sec->sh_type == SHT_NOBITS) {
|
|
pr_err("symbol %s is in a bss section. Cannot %s\n", name,
|
|
get_value ? "get" : "set");
|
|
return -EINVAL;
|
|
}
|
|
|
|
sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
|
|
|
|
if (get_value)
|
|
memcpy((void *)buf, sym_buf, size);
|
|
else
|
|
memcpy((void *)sym_buf, buf, size);
|
|
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY */
|