Commit 125ed24a authored Jul 31, 2022 by Masahiro Yamada

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 <masahiroy@kernel.org>

parent 36b0f0de

scripts/mod/modpost.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -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]);
		}