binfmt_flat: prevent kernel dammage from corrupted executable headers

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
This commit is contained in:
Nicolas Pitre 2016-07-24 11:30:17 -04:00 committed by Greg Ungerer
parent 4adbb6ac4b
commit c995ee28d2
1 changed files with 11 additions and 0 deletions

View File

@ -465,6 +465,17 @@ static int load_flat_file(struct linux_binprm *bprm,
goto err;
}
/*
* Make sure the header params are sane.
* 28 bits (256 MB) is way more than reasonable in this case.
* If some top bits are set we have probable binary corruption.
*/
if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
pr_err("bad header\n");
ret = -ENOEXEC;
goto err;
}
/*
* fix up the flags for the older format, there were all kinds
* of endian hacks, this only works for the simple cases