x86/ldt: Fix support_pte_mask filtering in map_ldt_struct()

The |= operator will let us end up with an invalid PTE. Use
the correct &= instead.

[ The bug was also independently reported by Shuah Khan ]

Fixes: fb43d6cb91 ('x86/mm: Do not auto-massage page protections')
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joerg Roedel 2018-04-16 11:43:57 +02:00 committed by Linus Torvalds
parent 60cc43fc88
commit e6f39e87b6

View File

@ -166,7 +166,7 @@ map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot)
*/
pte_prot = __pgprot(__PAGE_KERNEL_RO & ~_PAGE_GLOBAL);
/* Filter out unsuppored __PAGE_KERNEL* bits: */
pgprot_val(pte_prot) |= __supported_pte_mask;
pgprot_val(pte_prot) &= __supported_pte_mask;
pte = pfn_pte(pfn, pte_prot);
set_pte_at(mm, va, ptep, pte);
pte_unmap_unlock(ptep, ptl);