x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET

The oops can be triggered in qemu using -no-hpet (but not nohpet) by
running a 32-bit program and reading a couple of pages before the vdso.
This should send SIGBUS instead of OOPSing.

The bug was introduced by:

commit 7a59ed415f
Author: Stefani Seibold <stefani@seibold.net>
Date:   Mon Mar 17 23:22:09 2014 +0100

    x86, vdso: Add 32 bit VDSO time support for 32 bit kernel

which is new in 3.15.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/e99025d887d6670b6c4d81e6ccfeeb83770b21e9.1400109621.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Andy Lutomirski 2014-05-14 16:23:13 -07:00 committed by H. Peter Anvin
parent 4b660a7f5c
commit 368b69a5b0

View File

@ -155,6 +155,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
unsigned long addr;
int ret = 0;
struct vm_area_struct *vma;
static struct page *no_pages[] = {NULL};
#ifdef CONFIG_X86_X32_ABI
if (test_thread_flag(TIF_X32))
@ -193,7 +194,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
addr - VDSO_OFFSET(VDSO_PREV_PAGES),
VDSO_OFFSET(VDSO_PREV_PAGES),
VM_READ,
NULL);
no_pages);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);