From dee20035b42d569984d2c16041b51e4d75e233b5 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Sun, 12 May 2013 23:26:03 +0200 Subject: [PATCH] um: Mark stub pages mapping with VM_PFNMAP Ensure that a process cannot destroy his stub pages with using MADV_DONTNEED and friends. Reported-by: toralf.foerster@gmx.de Signed-off-by: Richard Weinberger --- arch/um/kernel/skas/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c index ff03067a3b14..007d5503f49b 100644 --- a/arch/um/kernel/skas/mmu.c +++ b/arch/um/kernel/skas/mmu.c @@ -123,7 +123,7 @@ void uml_setup_stubs(struct mm_struct *mm) /* dup_mmap already holds mmap_sem */ err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START, VM_READ | VM_MAYREAD | VM_EXEC | - VM_MAYEXEC | VM_DONTCOPY, + VM_MAYEXEC | VM_DONTCOPY | VM_PFNMAP, mm->context.stub_pages); if (err) { printk(KERN_ERR "install_special_mapping returned %d\n", err); -- 2.20.1