diff options
| author | Dave Hansen <dave.hansen@linux.intel.com> | 2018-04-20 15:20:28 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-04-25 11:02:51 +0200 |
| commit | 316d097c4cd4e7f2ef50c40cff2db266593c4ec4 (patch) | |
| tree | 0cbc41b328c814ddbfb51d9eb8e265f2a9cdb0e6 /mm | |
| parent | b7c21bc56fbedf4a61b628c6b11e0d7048746cc1 (diff) | |
x86/pti: Filter at vma->vm_page_prot population
commit ce9962bf7e22bb3891655c349faff618922d4a73
0day reported warnings at boot on 32-bit systems without NX support:
attempted to set unsupported pgprot: 8000000000000025 bits: 8000000000000000 supported: 7fffffffffffffff
WARNING: CPU: 0 PID: 1 at
arch/x86/include/asm/pgtable.h:540 handle_mm_fault+0xfc1/0xfe0:
check_pgprot at arch/x86/include/asm/pgtable.h:535
(inlined by) pfn_pte at arch/x86/include/asm/pgtable.h:549
(inlined by) do_anonymous_page at mm/memory.c:3169
(inlined by) handle_pte_fault at mm/memory.c:3961
(inlined by) __handle_mm_fault at mm/memory.c:4087
(inlined by) handle_mm_fault at mm/memory.c:4124
The problem is that due to the recent commit which removed auto-massaging
of page protections, filtering page permissions at PTE creation time is not
longer done, so vma->vm_page_prot is passed unfiltered to PTE creation.
Filter the page protections before they are installed in vma->vm_page_prot.
Fixes: fb43d6cb91 ("x86/mm: Do not auto-massage page protections")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Link: https://lkml.kernel.org/r/20180420222028.99D72858@viggo.jf.intel.com
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/mmap.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 188f195883b9..9d5968d1e8e3 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -100,11 +100,20 @@ pgprot_t protection_map[16] __ro_after_init = { __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111 }; +#ifndef CONFIG_ARCH_HAS_FILTER_PGPROT +static inline pgprot_t arch_filter_pgprot(pgprot_t prot) +{ + return prot; +} +#endif + pgprot_t vm_get_page_prot(unsigned long vm_flags) { - return __pgprot(pgprot_val(protection_map[vm_flags & + pgprot_t ret = __pgprot(pgprot_val(protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) | pgprot_val(arch_vm_get_page_prot(vm_flags))); + + return arch_filter_pgprot(ret); } EXPORT_SYMBOL(vm_get_page_prot); |