Messages in this thread Patch in this message | | | From | Masahiro Yamada <> | Subject | [PATCH 1/3] modpost: add array range check to sec_name() | Date | Sun, 31 Jul 2022 02:36:34 +0900 |
| |
The section index is always positive, so the argunent, secindex, should be unsigned.
Also, inserted the array range check.
If sym->st_shndx is a special section index (between SHN_LORESERVE and SHN_HIRESERVE), there is no corresponding section header.
For example, if a symbol specifies an absolute value, sym->st_shndx is SHN_ABS (=0xfff1).
The current users do not cause the out-of-range access of info->sechddrs[], but it is better to avoid such a pitfall.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> ---
scripts/mod/modpost.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 08411fff3e17..148b38699889 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -336,8 +336,16 @@ static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) sechdr->sh_name); } -static const char *sec_name(const struct elf_info *info, int secindex) +static const char *sec_name(const struct elf_info *info, unsigned int secindex) { + /* + * If sym->st_shndx is a special section index, there is no + * corresponding section header. + * Return "" if the index is out of range of info->sechdrs[] array. + */ + if (secindex >= info->num_sections) + return ""; + return sech_name(info, &info->sechdrs[secindex]); } -- 2.34.1
| |