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b1ae6dc41e
Current scheme of having userspace decompress kernel modules before loading them into the kernel runs afoul of LoadPin security policy, as it loses link between the source of kernel module on the disk and binary blob that is being loaded into the kernel. To solve this issue let's implement decompression in kernel, so that we can pass a file descriptor of compressed module file into finit_module() which will keep LoadPin happy. To let userspace know what compression/decompression scheme kernel supports it will create /sys/module/compression attribute. kmod can read this attribute and decide if it can pass compressed file to finit_module(). New MODULE_INIT_COMPRESSED_DATA flag indicates that the kernel should attempt to decompress the data read from file descriptor prior to trying load the module. To simplify things kernel will only implement single decompression method matching compression method selected when generating modules. This patch implements gzip and xz; more can be added later, Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
50 lines
1.2 KiB
C
50 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/* Module internals
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*
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* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#include <linux/elf.h>
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#include <asm/module.h>
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struct load_info {
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const char *name;
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/* pointer to module in temporary copy, freed at end of load_module() */
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struct module *mod;
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Elf_Ehdr *hdr;
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unsigned long len;
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Elf_Shdr *sechdrs;
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char *secstrings, *strtab;
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unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs;
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struct _ddebug *debug;
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unsigned int num_debug;
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bool sig_ok;
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#ifdef CONFIG_KALLSYMS
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unsigned long mod_kallsyms_init_off;
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#endif
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#ifdef CONFIG_MODULE_DECOMPRESS
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struct page **pages;
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unsigned int max_pages;
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unsigned int used_pages;
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#endif
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struct {
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unsigned int sym, str, mod, vers, info, pcpu;
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} index;
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};
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extern int mod_verify_sig(const void *mod, struct load_info *info);
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#ifdef CONFIG_MODULE_DECOMPRESS
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int module_decompress(struct load_info *info, const void *buf, size_t size);
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void module_decompress_cleanup(struct load_info *info);
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#else
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static inline int module_decompress(struct load_info *info,
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const void *buf, size_t size)
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{
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return -EOPNOTSUPP;
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}
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static inline void module_decompress_cleanup(struct load_info *info)
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{
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}
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#endif
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