| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <202501261836.WoV4syWH-lkp@intel.com>
Date: Sun, 26 Jan 2025 18:51:55 +0800
From: kernel test robot <lkp@...el.com>
To: Liao Chang <liaochang1@...wei.com>
Cc: oe-kbuild-all@...ts.linux.dev, linux-kernel@...r.kernel.org,
Palmer Dabbelt <palmer@...osinc.com>,
Li Zhengyu <lizhengyu3@...wei.com>
Subject: kernel/kexec_elf.c:253: warning: Function parameter or struct member
'elf_info' not described in 'elf_read_phdrs'
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: aa22f4da2a46b484a257d167c67a2adc1b7aaf68
commit: 6261586e0c91db14c34f894f4bc48f2300cff1d4 RISC-V: Add kexec_file support
date: 2 years, 8 months ago
config: riscv-randconfig-002-20240701 (https://download.01.org/0day-ci/archive/20250126/202501261836.WoV4syWH-lkp@intel.com/config)
compiler: riscv64-linux-gcc (GCC) 12.4.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250126/202501261836.WoV4syWH-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@...el.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501261836.WoV4syWH-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> kernel/kexec_elf.c:64: warning: Function parameter or struct member 'ehdr' not described in 'elf_is_ehdr_sane'
>> kernel/kexec_elf.c:186: warning: Function parameter or struct member 'phdr' not described in 'elf_is_phdr_sane'
>> kernel/kexec_elf.c:253: warning: Function parameter or struct member 'buf' not described in 'elf_read_phdrs'
>> kernel/kexec_elf.c:253: warning: Function parameter or struct member 'len' not described in 'elf_read_phdrs'
>> kernel/kexec_elf.c:253: warning: Function parameter or struct member 'elf_info' not described in 'elf_read_phdrs'
>> kernel/kexec_elf.c:320: warning: Function parameter or struct member 'elf_info' not described in 'kexec_free_elf_info'
>> kernel/kexec_elf.c:329: warning: Function parameter or struct member 'buf' not described in 'kexec_build_elf_info'
>> kernel/kexec_elf.c:329: warning: Function parameter or struct member 'len' not described in 'kexec_build_elf_info'
>> kernel/kexec_elf.c:329: warning: Function parameter or struct member 'ehdr' not described in 'kexec_build_elf_info'
>> kernel/kexec_elf.c:329: warning: Function parameter or struct member 'elf_info' not described in 'kexec_build_elf_info'
>> kernel/kexec_elf.c:392: warning: Function parameter or struct member 'image' not described in 'kexec_elf_load'
>> kernel/kexec_elf.c:392: warning: Function parameter or struct member 'ehdr' not described in 'kexec_elf_load'
>> kernel/kexec_elf.c:392: warning: Function parameter or struct member 'elf_info' not described in 'kexec_elf_load'
>> kernel/kexec_elf.c:392: warning: Function parameter or struct member 'kbuf' not described in 'kexec_elf_load'
vim +253 kernel/kexec_elf.c
175fca3bf91a111 Sven Schnelle 2019-08-23 58
175fca3bf91a111 Sven Schnelle 2019-08-23 59 /**
175fca3bf91a111 Sven Schnelle 2019-08-23 60 * elf_is_ehdr_sane - check that it is safe to use the ELF header
175fca3bf91a111 Sven Schnelle 2019-08-23 61 * @buf_len: size of the buffer in which the ELF file is loaded.
175fca3bf91a111 Sven Schnelle 2019-08-23 62 */
175fca3bf91a111 Sven Schnelle 2019-08-23 63 static bool elf_is_ehdr_sane(const struct elfhdr *ehdr, size_t buf_len)
175fca3bf91a111 Sven Schnelle 2019-08-23 @64 {
175fca3bf91a111 Sven Schnelle 2019-08-23 65 if (ehdr->e_phnum > 0 && ehdr->e_phentsize != sizeof(struct elf_phdr)) {
175fca3bf91a111 Sven Schnelle 2019-08-23 66 pr_debug("Bad program header size.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 67 return false;
175fca3bf91a111 Sven Schnelle 2019-08-23 68 } else if (ehdr->e_shnum > 0 &&
175fca3bf91a111 Sven Schnelle 2019-08-23 69 ehdr->e_shentsize != sizeof(struct elf_shdr)) {
175fca3bf91a111 Sven Schnelle 2019-08-23 70 pr_debug("Bad section header size.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 71 return false;
175fca3bf91a111 Sven Schnelle 2019-08-23 72 } else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT ||
175fca3bf91a111 Sven Schnelle 2019-08-23 73 ehdr->e_version != EV_CURRENT) {
175fca3bf91a111 Sven Schnelle 2019-08-23 74 pr_debug("Unknown ELF version.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 75 return false;
175fca3bf91a111 Sven Schnelle 2019-08-23 76 }
175fca3bf91a111 Sven Schnelle 2019-08-23 77
175fca3bf91a111 Sven Schnelle 2019-08-23 78 if (ehdr->e_phoff > 0 && ehdr->e_phnum > 0) {
175fca3bf91a111 Sven Schnelle 2019-08-23 79 size_t phdr_size;
175fca3bf91a111 Sven Schnelle 2019-08-23 80
175fca3bf91a111 Sven Schnelle 2019-08-23 81 /*
175fca3bf91a111 Sven Schnelle 2019-08-23 82 * e_phnum is at most 65535 so calculating the size of the
175fca3bf91a111 Sven Schnelle 2019-08-23 83 * program header cannot overflow.
175fca3bf91a111 Sven Schnelle 2019-08-23 84 */
175fca3bf91a111 Sven Schnelle 2019-08-23 85 phdr_size = sizeof(struct elf_phdr) * ehdr->e_phnum;
175fca3bf91a111 Sven Schnelle 2019-08-23 86
175fca3bf91a111 Sven Schnelle 2019-08-23 87 /* Sanity check the program header table location. */
175fca3bf91a111 Sven Schnelle 2019-08-23 88 if (ehdr->e_phoff + phdr_size < ehdr->e_phoff) {
175fca3bf91a111 Sven Schnelle 2019-08-23 89 pr_debug("Program headers at invalid location.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 90 return false;
175fca3bf91a111 Sven Schnelle 2019-08-23 91 } else if (ehdr->e_phoff + phdr_size > buf_len) {
175fca3bf91a111 Sven Schnelle 2019-08-23 92 pr_debug("Program headers truncated.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 93 return false;
175fca3bf91a111 Sven Schnelle 2019-08-23 94 }
175fca3bf91a111 Sven Schnelle 2019-08-23 95 }
175fca3bf91a111 Sven Schnelle 2019-08-23 96
175fca3bf91a111 Sven Schnelle 2019-08-23 97 if (ehdr->e_shoff > 0 && ehdr->e_shnum > 0) {
175fca3bf91a111 Sven Schnelle 2019-08-23 98 size_t shdr_size;
175fca3bf91a111 Sven Schnelle 2019-08-23 99
175fca3bf91a111 Sven Schnelle 2019-08-23 100 /*
175fca3bf91a111 Sven Schnelle 2019-08-23 101 * e_shnum is at most 65536 so calculating
175fca3bf91a111 Sven Schnelle 2019-08-23 102 * the size of the section header cannot overflow.
175fca3bf91a111 Sven Schnelle 2019-08-23 103 */
175fca3bf91a111 Sven Schnelle 2019-08-23 104 shdr_size = sizeof(struct elf_shdr) * ehdr->e_shnum;
175fca3bf91a111 Sven Schnelle 2019-08-23 105
175fca3bf91a111 Sven Schnelle 2019-08-23 106 /* Sanity check the section header table location. */
175fca3bf91a111 Sven Schnelle 2019-08-23 107 if (ehdr->e_shoff + shdr_size < ehdr->e_shoff) {
175fca3bf91a111 Sven Schnelle 2019-08-23 108 pr_debug("Section headers at invalid location.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 109 return false;
175fca3bf91a111 Sven Schnelle 2019-08-23 110 } else if (ehdr->e_shoff + shdr_size > buf_len) {
175fca3bf91a111 Sven Schnelle 2019-08-23 111 pr_debug("Section headers truncated.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 112 return false;
175fca3bf91a111 Sven Schnelle 2019-08-23 113 }
175fca3bf91a111 Sven Schnelle 2019-08-23 114 }
175fca3bf91a111 Sven Schnelle 2019-08-23 115
175fca3bf91a111 Sven Schnelle 2019-08-23 116 return true;
175fca3bf91a111 Sven Schnelle 2019-08-23 117 }
175fca3bf91a111 Sven Schnelle 2019-08-23 118
175fca3bf91a111 Sven Schnelle 2019-08-23 119 static int elf_read_ehdr(const char *buf, size_t len, struct elfhdr *ehdr)
175fca3bf91a111 Sven Schnelle 2019-08-23 120 {
175fca3bf91a111 Sven Schnelle 2019-08-23 121 struct elfhdr *buf_ehdr;
175fca3bf91a111 Sven Schnelle 2019-08-23 122
175fca3bf91a111 Sven Schnelle 2019-08-23 123 if (len < sizeof(*buf_ehdr)) {
175fca3bf91a111 Sven Schnelle 2019-08-23 124 pr_debug("Buffer is too small to hold ELF header.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 125 return -ENOEXEC;
175fca3bf91a111 Sven Schnelle 2019-08-23 126 }
175fca3bf91a111 Sven Schnelle 2019-08-23 127
175fca3bf91a111 Sven Schnelle 2019-08-23 128 memset(ehdr, 0, sizeof(*ehdr));
175fca3bf91a111 Sven Schnelle 2019-08-23 129 memcpy(ehdr->e_ident, buf, sizeof(ehdr->e_ident));
175fca3bf91a111 Sven Schnelle 2019-08-23 130 if (!elf_is_elf_file(ehdr)) {
175fca3bf91a111 Sven Schnelle 2019-08-23 131 pr_debug("No ELF header magic.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 132 return -ENOEXEC;
175fca3bf91a111 Sven Schnelle 2019-08-23 133 }
175fca3bf91a111 Sven Schnelle 2019-08-23 134
175fca3bf91a111 Sven Schnelle 2019-08-23 135 if (ehdr->e_ident[EI_CLASS] != ELF_CLASS) {
175fca3bf91a111 Sven Schnelle 2019-08-23 136 pr_debug("Not a supported ELF class.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 137 return -ENOEXEC;
175fca3bf91a111 Sven Schnelle 2019-08-23 138 } else if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB &&
175fca3bf91a111 Sven Schnelle 2019-08-23 139 ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
175fca3bf91a111 Sven Schnelle 2019-08-23 140 pr_debug("Not a supported ELF data format.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 141 return -ENOEXEC;
175fca3bf91a111 Sven Schnelle 2019-08-23 142 }
175fca3bf91a111 Sven Schnelle 2019-08-23 143
175fca3bf91a111 Sven Schnelle 2019-08-23 144 buf_ehdr = (struct elfhdr *) buf;
175fca3bf91a111 Sven Schnelle 2019-08-23 145 if (elf16_to_cpu(ehdr, buf_ehdr->e_ehsize) != sizeof(*buf_ehdr)) {
175fca3bf91a111 Sven Schnelle 2019-08-23 146 pr_debug("Bad ELF header size.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 147 return -ENOEXEC;
175fca3bf91a111 Sven Schnelle 2019-08-23 148 }
175fca3bf91a111 Sven Schnelle 2019-08-23 149
175fca3bf91a111 Sven Schnelle 2019-08-23 150 ehdr->e_type = elf16_to_cpu(ehdr, buf_ehdr->e_type);
175fca3bf91a111 Sven Schnelle 2019-08-23 151 ehdr->e_machine = elf16_to_cpu(ehdr, buf_ehdr->e_machine);
175fca3bf91a111 Sven Schnelle 2019-08-23 152 ehdr->e_version = elf32_to_cpu(ehdr, buf_ehdr->e_version);
175fca3bf91a111 Sven Schnelle 2019-08-23 153 ehdr->e_flags = elf32_to_cpu(ehdr, buf_ehdr->e_flags);
175fca3bf91a111 Sven Schnelle 2019-08-23 154 ehdr->e_phentsize = elf16_to_cpu(ehdr, buf_ehdr->e_phentsize);
175fca3bf91a111 Sven Schnelle 2019-08-23 155 ehdr->e_phnum = elf16_to_cpu(ehdr, buf_ehdr->e_phnum);
175fca3bf91a111 Sven Schnelle 2019-08-23 156 ehdr->e_shentsize = elf16_to_cpu(ehdr, buf_ehdr->e_shentsize);
175fca3bf91a111 Sven Schnelle 2019-08-23 157 ehdr->e_shnum = elf16_to_cpu(ehdr, buf_ehdr->e_shnum);
175fca3bf91a111 Sven Schnelle 2019-08-23 158 ehdr->e_shstrndx = elf16_to_cpu(ehdr, buf_ehdr->e_shstrndx);
175fca3bf91a111 Sven Schnelle 2019-08-23 159
ea46a13ebf53669 Sven Schnelle 2019-08-23 160 switch (ehdr->e_ident[EI_CLASS]) {
ea46a13ebf53669 Sven Schnelle 2019-08-23 161 case ELFCLASS64:
ea46a13ebf53669 Sven Schnelle 2019-08-23 162 ehdr->e_entry = elf64_to_cpu(ehdr, buf_ehdr->e_entry);
ea46a13ebf53669 Sven Schnelle 2019-08-23 163 ehdr->e_phoff = elf64_to_cpu(ehdr, buf_ehdr->e_phoff);
ea46a13ebf53669 Sven Schnelle 2019-08-23 164 ehdr->e_shoff = elf64_to_cpu(ehdr, buf_ehdr->e_shoff);
ea46a13ebf53669 Sven Schnelle 2019-08-23 165 break;
ea46a13ebf53669 Sven Schnelle 2019-08-23 166
ea46a13ebf53669 Sven Schnelle 2019-08-23 167 case ELFCLASS32:
ea46a13ebf53669 Sven Schnelle 2019-08-23 168 ehdr->e_entry = elf32_to_cpu(ehdr, buf_ehdr->e_entry);
ea46a13ebf53669 Sven Schnelle 2019-08-23 169 ehdr->e_phoff = elf32_to_cpu(ehdr, buf_ehdr->e_phoff);
ea46a13ebf53669 Sven Schnelle 2019-08-23 170 ehdr->e_shoff = elf32_to_cpu(ehdr, buf_ehdr->e_shoff);
ea46a13ebf53669 Sven Schnelle 2019-08-23 171 break;
ea46a13ebf53669 Sven Schnelle 2019-08-23 172
ea46a13ebf53669 Sven Schnelle 2019-08-23 173 default:
ea46a13ebf53669 Sven Schnelle 2019-08-23 174 pr_debug("Unknown ELF class.\n");
ea46a13ebf53669 Sven Schnelle 2019-08-23 175 return -EINVAL;
ea46a13ebf53669 Sven Schnelle 2019-08-23 176 }
ea46a13ebf53669 Sven Schnelle 2019-08-23 177
175fca3bf91a111 Sven Schnelle 2019-08-23 178 return elf_is_ehdr_sane(ehdr, len) ? 0 : -ENOEXEC;
175fca3bf91a111 Sven Schnelle 2019-08-23 179 }
175fca3bf91a111 Sven Schnelle 2019-08-23 180
175fca3bf91a111 Sven Schnelle 2019-08-23 181 /**
175fca3bf91a111 Sven Schnelle 2019-08-23 182 * elf_is_phdr_sane - check that it is safe to use the program header
175fca3bf91a111 Sven Schnelle 2019-08-23 183 * @buf_len: size of the buffer in which the ELF file is loaded.
175fca3bf91a111 Sven Schnelle 2019-08-23 184 */
175fca3bf91a111 Sven Schnelle 2019-08-23 185 static bool elf_is_phdr_sane(const struct elf_phdr *phdr, size_t buf_len)
175fca3bf91a111 Sven Schnelle 2019-08-23 @186 {
175fca3bf91a111 Sven Schnelle 2019-08-23 187
175fca3bf91a111 Sven Schnelle 2019-08-23 188 if (phdr->p_offset + phdr->p_filesz < phdr->p_offset) {
175fca3bf91a111 Sven Schnelle 2019-08-23 189 pr_debug("ELF segment location wraps around.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 190 return false;
175fca3bf91a111 Sven Schnelle 2019-08-23 191 } else if (phdr->p_offset + phdr->p_filesz > buf_len) {
175fca3bf91a111 Sven Schnelle 2019-08-23 192 pr_debug("ELF segment not in file.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 193 return false;
175fca3bf91a111 Sven Schnelle 2019-08-23 194 } else if (phdr->p_paddr + phdr->p_memsz < phdr->p_paddr) {
175fca3bf91a111 Sven Schnelle 2019-08-23 195 pr_debug("ELF segment address wraps around.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 196 return false;
175fca3bf91a111 Sven Schnelle 2019-08-23 197 }
175fca3bf91a111 Sven Schnelle 2019-08-23 198
175fca3bf91a111 Sven Schnelle 2019-08-23 199 return true;
175fca3bf91a111 Sven Schnelle 2019-08-23 200 }
175fca3bf91a111 Sven Schnelle 2019-08-23 201
175fca3bf91a111 Sven Schnelle 2019-08-23 202 static int elf_read_phdr(const char *buf, size_t len,
175fca3bf91a111 Sven Schnelle 2019-08-23 203 struct kexec_elf_info *elf_info,
175fca3bf91a111 Sven Schnelle 2019-08-23 204 int idx)
175fca3bf91a111 Sven Schnelle 2019-08-23 205 {
175fca3bf91a111 Sven Schnelle 2019-08-23 206 /* Override the const in proghdrs, we are the ones doing the loading. */
175fca3bf91a111 Sven Schnelle 2019-08-23 207 struct elf_phdr *phdr = (struct elf_phdr *) &elf_info->proghdrs[idx];
ea46a13ebf53669 Sven Schnelle 2019-08-23 208 const struct elfhdr *ehdr = elf_info->ehdr;
175fca3bf91a111 Sven Schnelle 2019-08-23 209 const char *pbuf;
175fca3bf91a111 Sven Schnelle 2019-08-23 210 struct elf_phdr *buf_phdr;
175fca3bf91a111 Sven Schnelle 2019-08-23 211
175fca3bf91a111 Sven Schnelle 2019-08-23 212 pbuf = buf + elf_info->ehdr->e_phoff + (idx * sizeof(*buf_phdr));
175fca3bf91a111 Sven Schnelle 2019-08-23 213 buf_phdr = (struct elf_phdr *) pbuf;
175fca3bf91a111 Sven Schnelle 2019-08-23 214
175fca3bf91a111 Sven Schnelle 2019-08-23 215 phdr->p_type = elf32_to_cpu(elf_info->ehdr, buf_phdr->p_type);
175fca3bf91a111 Sven Schnelle 2019-08-23 216 phdr->p_flags = elf32_to_cpu(elf_info->ehdr, buf_phdr->p_flags);
175fca3bf91a111 Sven Schnelle 2019-08-23 217
ea46a13ebf53669 Sven Schnelle 2019-08-23 218 switch (ehdr->e_ident[EI_CLASS]) {
ea46a13ebf53669 Sven Schnelle 2019-08-23 219 case ELFCLASS64:
ea46a13ebf53669 Sven Schnelle 2019-08-23 220 phdr->p_offset = elf64_to_cpu(ehdr, buf_phdr->p_offset);
ea46a13ebf53669 Sven Schnelle 2019-08-23 221 phdr->p_paddr = elf64_to_cpu(ehdr, buf_phdr->p_paddr);
ea46a13ebf53669 Sven Schnelle 2019-08-23 222 phdr->p_vaddr = elf64_to_cpu(ehdr, buf_phdr->p_vaddr);
ea46a13ebf53669 Sven Schnelle 2019-08-23 223 phdr->p_filesz = elf64_to_cpu(ehdr, buf_phdr->p_filesz);
ea46a13ebf53669 Sven Schnelle 2019-08-23 224 phdr->p_memsz = elf64_to_cpu(ehdr, buf_phdr->p_memsz);
ea46a13ebf53669 Sven Schnelle 2019-08-23 225 phdr->p_align = elf64_to_cpu(ehdr, buf_phdr->p_align);
ea46a13ebf53669 Sven Schnelle 2019-08-23 226 break;
ea46a13ebf53669 Sven Schnelle 2019-08-23 227
ea46a13ebf53669 Sven Schnelle 2019-08-23 228 case ELFCLASS32:
ea46a13ebf53669 Sven Schnelle 2019-08-23 229 phdr->p_offset = elf32_to_cpu(ehdr, buf_phdr->p_offset);
ea46a13ebf53669 Sven Schnelle 2019-08-23 230 phdr->p_paddr = elf32_to_cpu(ehdr, buf_phdr->p_paddr);
ea46a13ebf53669 Sven Schnelle 2019-08-23 231 phdr->p_vaddr = elf32_to_cpu(ehdr, buf_phdr->p_vaddr);
ea46a13ebf53669 Sven Schnelle 2019-08-23 232 phdr->p_filesz = elf32_to_cpu(ehdr, buf_phdr->p_filesz);
ea46a13ebf53669 Sven Schnelle 2019-08-23 233 phdr->p_memsz = elf32_to_cpu(ehdr, buf_phdr->p_memsz);
ea46a13ebf53669 Sven Schnelle 2019-08-23 234 phdr->p_align = elf32_to_cpu(ehdr, buf_phdr->p_align);
ea46a13ebf53669 Sven Schnelle 2019-08-23 235 break;
ea46a13ebf53669 Sven Schnelle 2019-08-23 236
ea46a13ebf53669 Sven Schnelle 2019-08-23 237 default:
ea46a13ebf53669 Sven Schnelle 2019-08-23 238 pr_debug("Unknown ELF class.\n");
ea46a13ebf53669 Sven Schnelle 2019-08-23 239 return -EINVAL;
ea46a13ebf53669 Sven Schnelle 2019-08-23 240 }
175fca3bf91a111 Sven Schnelle 2019-08-23 241
175fca3bf91a111 Sven Schnelle 2019-08-23 242 return elf_is_phdr_sane(phdr, len) ? 0 : -ENOEXEC;
175fca3bf91a111 Sven Schnelle 2019-08-23 243 }
175fca3bf91a111 Sven Schnelle 2019-08-23 244
175fca3bf91a111 Sven Schnelle 2019-08-23 245 /**
175fca3bf91a111 Sven Schnelle 2019-08-23 246 * elf_read_phdrs - read the program headers from the buffer
175fca3bf91a111 Sven Schnelle 2019-08-23 247 *
175fca3bf91a111 Sven Schnelle 2019-08-23 248 * This function assumes that the program header table was checked for sanity.
175fca3bf91a111 Sven Schnelle 2019-08-23 249 * Use elf_is_ehdr_sane() if it wasn't.
175fca3bf91a111 Sven Schnelle 2019-08-23 250 */
175fca3bf91a111 Sven Schnelle 2019-08-23 251 static int elf_read_phdrs(const char *buf, size_t len,
175fca3bf91a111 Sven Schnelle 2019-08-23 252 struct kexec_elf_info *elf_info)
175fca3bf91a111 Sven Schnelle 2019-08-23 @253 {
175fca3bf91a111 Sven Schnelle 2019-08-23 254 size_t phdr_size, i;
175fca3bf91a111 Sven Schnelle 2019-08-23 255 const struct elfhdr *ehdr = elf_info->ehdr;
175fca3bf91a111 Sven Schnelle 2019-08-23 256
175fca3bf91a111 Sven Schnelle 2019-08-23 257 /*
175fca3bf91a111 Sven Schnelle 2019-08-23 258 * e_phnum is at most 65535 so calculating the size of the
175fca3bf91a111 Sven Schnelle 2019-08-23 259 * program header cannot overflow.
175fca3bf91a111 Sven Schnelle 2019-08-23 260 */
175fca3bf91a111 Sven Schnelle 2019-08-23 261 phdr_size = sizeof(struct elf_phdr) * ehdr->e_phnum;
175fca3bf91a111 Sven Schnelle 2019-08-23 262
175fca3bf91a111 Sven Schnelle 2019-08-23 263 elf_info->proghdrs = kzalloc(phdr_size, GFP_KERNEL);
175fca3bf91a111 Sven Schnelle 2019-08-23 264 if (!elf_info->proghdrs)
175fca3bf91a111 Sven Schnelle 2019-08-23 265 return -ENOMEM;
175fca3bf91a111 Sven Schnelle 2019-08-23 266
175fca3bf91a111 Sven Schnelle 2019-08-23 267 for (i = 0; i < ehdr->e_phnum; i++) {
175fca3bf91a111 Sven Schnelle 2019-08-23 268 int ret;
175fca3bf91a111 Sven Schnelle 2019-08-23 269
175fca3bf91a111 Sven Schnelle 2019-08-23 270 ret = elf_read_phdr(buf, len, elf_info, i);
175fca3bf91a111 Sven Schnelle 2019-08-23 271 if (ret) {
175fca3bf91a111 Sven Schnelle 2019-08-23 272 kfree(elf_info->proghdrs);
175fca3bf91a111 Sven Schnelle 2019-08-23 273 elf_info->proghdrs = NULL;
175fca3bf91a111 Sven Schnelle 2019-08-23 274 return ret;
175fca3bf91a111 Sven Schnelle 2019-08-23 275 }
175fca3bf91a111 Sven Schnelle 2019-08-23 276 }
175fca3bf91a111 Sven Schnelle 2019-08-23 277
175fca3bf91a111 Sven Schnelle 2019-08-23 278 return 0;
175fca3bf91a111 Sven Schnelle 2019-08-23 279 }
175fca3bf91a111 Sven Schnelle 2019-08-23 280
175fca3bf91a111 Sven Schnelle 2019-08-23 281 /**
175fca3bf91a111 Sven Schnelle 2019-08-23 282 * elf_read_from_buffer - read ELF file and sets up ELF header and ELF info
175fca3bf91a111 Sven Schnelle 2019-08-23 283 * @buf: Buffer to read ELF file from.
175fca3bf91a111 Sven Schnelle 2019-08-23 284 * @len: Size of @buf.
175fca3bf91a111 Sven Schnelle 2019-08-23 285 * @ehdr: Pointer to existing struct which will be populated.
175fca3bf91a111 Sven Schnelle 2019-08-23 286 * @elf_info: Pointer to existing struct which will be populated.
175fca3bf91a111 Sven Schnelle 2019-08-23 287 *
175fca3bf91a111 Sven Schnelle 2019-08-23 288 * This function allows reading ELF files with different byte order than
175fca3bf91a111 Sven Schnelle 2019-08-23 289 * the kernel, byte-swapping the fields as needed.
175fca3bf91a111 Sven Schnelle 2019-08-23 290 *
175fca3bf91a111 Sven Schnelle 2019-08-23 291 * Return:
175fca3bf91a111 Sven Schnelle 2019-08-23 292 * On success returns 0, and the caller should call
175fca3bf91a111 Sven Schnelle 2019-08-23 293 * kexec_free_elf_info(elf_info) to free the memory allocated for the section
175fca3bf91a111 Sven Schnelle 2019-08-23 294 * and program headers.
175fca3bf91a111 Sven Schnelle 2019-08-23 295 */
175fca3bf91a111 Sven Schnelle 2019-08-23 296 static int elf_read_from_buffer(const char *buf, size_t len,
175fca3bf91a111 Sven Schnelle 2019-08-23 297 struct elfhdr *ehdr,
175fca3bf91a111 Sven Schnelle 2019-08-23 298 struct kexec_elf_info *elf_info)
175fca3bf91a111 Sven Schnelle 2019-08-23 299 {
175fca3bf91a111 Sven Schnelle 2019-08-23 300 int ret;
175fca3bf91a111 Sven Schnelle 2019-08-23 301
175fca3bf91a111 Sven Schnelle 2019-08-23 302 ret = elf_read_ehdr(buf, len, ehdr);
175fca3bf91a111 Sven Schnelle 2019-08-23 303 if (ret)
175fca3bf91a111 Sven Schnelle 2019-08-23 304 return ret;
175fca3bf91a111 Sven Schnelle 2019-08-23 305
175fca3bf91a111 Sven Schnelle 2019-08-23 306 elf_info->buffer = buf;
175fca3bf91a111 Sven Schnelle 2019-08-23 307 elf_info->ehdr = ehdr;
175fca3bf91a111 Sven Schnelle 2019-08-23 308 if (ehdr->e_phoff > 0 && ehdr->e_phnum > 0) {
175fca3bf91a111 Sven Schnelle 2019-08-23 309 ret = elf_read_phdrs(buf, len, elf_info);
175fca3bf91a111 Sven Schnelle 2019-08-23 310 if (ret)
175fca3bf91a111 Sven Schnelle 2019-08-23 311 return ret;
175fca3bf91a111 Sven Schnelle 2019-08-23 312 }
175fca3bf91a111 Sven Schnelle 2019-08-23 313 return 0;
175fca3bf91a111 Sven Schnelle 2019-08-23 314 }
175fca3bf91a111 Sven Schnelle 2019-08-23 315
175fca3bf91a111 Sven Schnelle 2019-08-23 316 /**
175fca3bf91a111 Sven Schnelle 2019-08-23 317 * kexec_free_elf_info - free memory allocated by elf_read_from_buffer
175fca3bf91a111 Sven Schnelle 2019-08-23 318 */
175fca3bf91a111 Sven Schnelle 2019-08-23 319 void kexec_free_elf_info(struct kexec_elf_info *elf_info)
175fca3bf91a111 Sven Schnelle 2019-08-23 @320 {
175fca3bf91a111 Sven Schnelle 2019-08-23 321 kfree(elf_info->proghdrs);
175fca3bf91a111 Sven Schnelle 2019-08-23 322 memset(elf_info, 0, sizeof(*elf_info));
175fca3bf91a111 Sven Schnelle 2019-08-23 323 }
175fca3bf91a111 Sven Schnelle 2019-08-23 324 /**
175fca3bf91a111 Sven Schnelle 2019-08-23 325 * kexec_build_elf_info - read ELF executable and check that we can use it
175fca3bf91a111 Sven Schnelle 2019-08-23 326 */
175fca3bf91a111 Sven Schnelle 2019-08-23 327 int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr,
175fca3bf91a111 Sven Schnelle 2019-08-23 328 struct kexec_elf_info *elf_info)
175fca3bf91a111 Sven Schnelle 2019-08-23 @329 {
175fca3bf91a111 Sven Schnelle 2019-08-23 330 int i;
175fca3bf91a111 Sven Schnelle 2019-08-23 331 int ret;
175fca3bf91a111 Sven Schnelle 2019-08-23 332
175fca3bf91a111 Sven Schnelle 2019-08-23 333 ret = elf_read_from_buffer(buf, len, ehdr, elf_info);
175fca3bf91a111 Sven Schnelle 2019-08-23 334 if (ret)
175fca3bf91a111 Sven Schnelle 2019-08-23 335 return ret;
175fca3bf91a111 Sven Schnelle 2019-08-23 336
175fca3bf91a111 Sven Schnelle 2019-08-23 337 /* Big endian vmlinux has type ET_DYN. */
175fca3bf91a111 Sven Schnelle 2019-08-23 338 if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) {
175fca3bf91a111 Sven Schnelle 2019-08-23 339 pr_err("Not an ELF executable.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 340 goto error;
175fca3bf91a111 Sven Schnelle 2019-08-23 341 } else if (!elf_info->proghdrs) {
175fca3bf91a111 Sven Schnelle 2019-08-23 342 pr_err("No ELF program header.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 343 goto error;
175fca3bf91a111 Sven Schnelle 2019-08-23 344 }
175fca3bf91a111 Sven Schnelle 2019-08-23 345
175fca3bf91a111 Sven Schnelle 2019-08-23 346 for (i = 0; i < ehdr->e_phnum; i++) {
175fca3bf91a111 Sven Schnelle 2019-08-23 347 /*
175fca3bf91a111 Sven Schnelle 2019-08-23 348 * Kexec does not support loading interpreters.
175fca3bf91a111 Sven Schnelle 2019-08-23 349 * In addition this check keeps us from attempting
175fca3bf91a111 Sven Schnelle 2019-08-23 350 * to kexec ordinay executables.
175fca3bf91a111 Sven Schnelle 2019-08-23 351 */
175fca3bf91a111 Sven Schnelle 2019-08-23 352 if (elf_info->proghdrs[i].p_type == PT_INTERP) {
175fca3bf91a111 Sven Schnelle 2019-08-23 353 pr_err("Requires an ELF interpreter.\n");
175fca3bf91a111 Sven Schnelle 2019-08-23 354 goto error;
175fca3bf91a111 Sven Schnelle 2019-08-23 355 }
175fca3bf91a111 Sven Schnelle 2019-08-23 356 }
175fca3bf91a111 Sven Schnelle 2019-08-23 357
175fca3bf91a111 Sven Schnelle 2019-08-23 358 return 0;
175fca3bf91a111 Sven Schnelle 2019-08-23 359 error:
175fca3bf91a111 Sven Schnelle 2019-08-23 360 kexec_free_elf_info(elf_info);
175fca3bf91a111 Sven Schnelle 2019-08-23 361 return -ENOEXEC;
175fca3bf91a111 Sven Schnelle 2019-08-23 362 }
175fca3bf91a111 Sven Schnelle 2019-08-23 363
175fca3bf91a111 Sven Schnelle 2019-08-23 364
175fca3bf91a111 Sven Schnelle 2019-08-23 365 int kexec_elf_probe(const char *buf, unsigned long len)
175fca3bf91a111 Sven Schnelle 2019-08-23 366 {
175fca3bf91a111 Sven Schnelle 2019-08-23 367 struct elfhdr ehdr;
175fca3bf91a111 Sven Schnelle 2019-08-23 368 struct kexec_elf_info elf_info;
175fca3bf91a111 Sven Schnelle 2019-08-23 369 int ret;
175fca3bf91a111 Sven Schnelle 2019-08-23 370
175fca3bf91a111 Sven Schnelle 2019-08-23 371 ret = kexec_build_elf_info(buf, len, &ehdr, &elf_info);
175fca3bf91a111 Sven Schnelle 2019-08-23 372 if (ret)
175fca3bf91a111 Sven Schnelle 2019-08-23 373 return ret;
175fca3bf91a111 Sven Schnelle 2019-08-23 374
175fca3bf91a111 Sven Schnelle 2019-08-23 375 kexec_free_elf_info(&elf_info);
175fca3bf91a111 Sven Schnelle 2019-08-23 376
175fca3bf91a111 Sven Schnelle 2019-08-23 377 return elf_check_arch(&ehdr) ? 0 : -ENOEXEC;
175fca3bf91a111 Sven Schnelle 2019-08-23 378 }
175fca3bf91a111 Sven Schnelle 2019-08-23 379
175fca3bf91a111 Sven Schnelle 2019-08-23 380 /**
175fca3bf91a111 Sven Schnelle 2019-08-23 381 * kexec_elf_load - load ELF executable image
175fca3bf91a111 Sven Schnelle 2019-08-23 382 * @lowest_load_addr: On return, will be the address where the first PT_LOAD
175fca3bf91a111 Sven Schnelle 2019-08-23 383 * section will be loaded in memory.
175fca3bf91a111 Sven Schnelle 2019-08-23 384 *
175fca3bf91a111 Sven Schnelle 2019-08-23 385 * Return:
175fca3bf91a111 Sven Schnelle 2019-08-23 386 * 0 on success, negative value on failure.
175fca3bf91a111 Sven Schnelle 2019-08-23 387 */
175fca3bf91a111 Sven Schnelle 2019-08-23 388 int kexec_elf_load(struct kimage *image, struct elfhdr *ehdr,
175fca3bf91a111 Sven Schnelle 2019-08-23 389 struct kexec_elf_info *elf_info,
175fca3bf91a111 Sven Schnelle 2019-08-23 390 struct kexec_buf *kbuf,
175fca3bf91a111 Sven Schnelle 2019-08-23 391 unsigned long *lowest_load_addr)
175fca3bf91a111 Sven Schnelle 2019-08-23 @392 {
:::::: The code at line 253 was first introduced by commit
:::::: 175fca3bf91a1111b7e46f6655666640556b9059 kexec: add KEXEC_ELF
:::::: TO: Sven Schnelle <svens@...ckframe.org>
:::::: CC: Helge Deller <deller@....de>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Powered by blists - more mailing lists