Guard check in module loader against integer overflow

The check:

	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))

may not work if there's an overflow in the right-hand side of the condition.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
David Howells 2012-05-22 15:56:13 +01:00 committed by Rusty Russell
parent 3c7ec94d2c
commit ef26a5a6ea

View File

@ -2429,7 +2429,8 @@ static int copy_and_check(struct load_info *info,
goto free_hdr;
}
if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
if (hdr->e_shoff >= len ||
hdr->e_shnum * sizeof(Elf_Shdr) > len - hdr->e_shoff) {
err = -ENOEXEC;
goto free_hdr;
}