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| author | Matthew Maurer <mmaurer@google.com> | 2024-10-15 23:16:42 +0000 |
|---|---|---|
| committer | Luis Chamberlain <mcgrof@kernel.org> | 2024-10-19 14:35:07 -0700 |
| commit | 0a9395334496d3be8bde491e46087540cb8f141d (patch) | |
| tree | 4aafb294be66b66df557b9b4f293c8f50b30f126 /kernel/module | |
| parent | 9bd4982cf7d65f4c9e0793d5a8fda6ad838e8554 (diff) | |
| download | linux-0a9395334496d3be8bde491e46087540cb8f141d.tar.gz linux-0a9395334496d3be8bde491e46087540cb8f141d.tar.bz2 linux-0a9395334496d3be8bde491e46087540cb8f141d.zip | |
module: Factor out elf_validity_cache_index_str
Pull out index validation for the symbol string section.
Note that this does not validate the *contents* of the string table,
only shape and presence of the section.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Diffstat (limited to 'kernel/module')
| -rw-r--r-- | kernel/module/main.c | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/kernel/module/main.c b/kernel/module/main.c index 6be58b0a6468..43140475aac0 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -2014,6 +2014,31 @@ static int elf_validity_cache_index_sym(struct load_info *info) return 0; } +/** + * elf_validity_cache_index_str() - Validate and cache strtab index + * @info: Load info to cache strtab index in. + * Must have &load_info->sechdrs and &load_info->secstrings populated. + * Must have &load_info->index.sym populated. + * + * Looks at the symbol table's associated string table, makes sure it is + * in-bounds, and caches it. + * + * Return: %0 if valid, %-ENOEXEC on failure. + */ +static int elf_validity_cache_index_str(struct load_info *info) +{ + unsigned int str_idx = info->sechdrs[info->index.sym].sh_link; + + if (str_idx == SHN_UNDEF || str_idx >= info->hdr->e_shnum) { + pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n", + str_idx, str_idx, info->hdr->e_shnum); + return -ENOEXEC; + } + + info->index.str = str_idx; + return 0; +} + /* * Check userspace passed ELF module against our expectations, and cache * useful variables for further processing as we go. @@ -2037,7 +2062,6 @@ static int elf_validity_cache_index_sym(struct load_info *info) static int elf_validity_cache_copy(struct load_info *info, int flags) { int err; - int str_idx; err = elf_validity_cache_sechdrs(info); if (err < 0) @@ -2054,16 +2078,11 @@ static int elf_validity_cache_copy(struct load_info *info, int flags) err = elf_validity_cache_index_sym(info); if (err < 0) return err; - - str_idx = info->sechdrs[info->index.sym].sh_link; - if (str_idx == SHN_UNDEF || str_idx >= info->hdr->e_shnum) { - pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n", - str_idx, str_idx, info->hdr->e_shnum); - return -ENOEXEC; - } + err = elf_validity_cache_index_str(info); + if (err < 0) + return err; /* Sets internal strings. */ - info->index.str = str_idx; info->strtab = (char *)info->hdr + info->sechdrs[info->index.str].sh_offset; /* This is temporary: point mod into copy of data. */ |