From 125ed24a4ab0d704bab5dee5ccb2c3b05f627c78 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 31 Jul 2022 02:36:34 +0900 Subject: [PATCH] modpost: add array range check to sec_name() The section index is always positive, so the argument, 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 --- 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 08411ff..148b386 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]); } -- 2.7.4