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Commit e6f39e87 authored by Joerg Roedel's avatar Joerg Roedel Committed by Linus Torvalds
Browse files

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: fb43d6cb ('x86/mm: Do not auto-massage page protections')
Acked-by: default avatarAndy Lutomirski <luto@kernel.org>
Acked-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 60cc43fc

arch/x86/kernel/ldt.c

+1 −1
Original line number Diff line number Diff line
@@ -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);