3.14-stable patches

added patches:
	mm-avoid-setting-up-anonymous-pages-into-file-mapping.patch

diff --git a/queue-3.14/mm-avoid-setting-up-anonymous-pages-into-file-mapping.patch b/queue-3.14/mm-avoid-setting-up-anonymous-pages-into-file-mapping.patch
new file mode 100644 (file)
index 0000000..c5b9552
--- /dev/null
+++ b/queue-3.14/mm-avoid-setting-up-anonymous-pages-into-file-mapping.patch
@@ -0,0 +1,72 @@
+From 6b7339f4c31ad69c8e9c0b2859276e22cf72176d Mon Sep 17 00:00:00 2001
+From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
+Date: Mon, 6 Jul 2015 23:18:37 +0300
+Subject: mm: avoid setting up anonymous pages into file mapping
+
+From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
+
+commit 6b7339f4c31ad69c8e9c0b2859276e22cf72176d upstream.
+
+Reading page fault handler code I've noticed that under right
+circumstances kernel would map anonymous pages into file mappings: if
+the VMA doesn't have vm_ops->fault() and the VMA wasn't fully populated
+on ->mmap(), kernel would handle page fault to not populated pte with
+do_anonymous_page().
+
+Let's change page fault handler to use do_anonymous_page() only on
+anonymous VMA (->vm_ops == NULL) and make sure that the VMA is not
+shared.
+
+For file mappings without vm_ops->fault() or shred VMA without vm_ops,
+page fault on pte_none() entry would lead to SIGBUS.
+
+Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+Acked-by: Oleg Nesterov <oleg@redhat.com>
+Cc: Andrew Morton <akpm@linux-foundation.org>
+Cc: Willy Tarreau <w@1wt.eu>
+Cc: stable@vger.kernel.org
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ mm/memory.c |   13 +++++++++----
+ 1 file changed, 9 insertions(+), 4 deletions(-)
+
+--- a/mm/memory.c
++++ b/mm/memory.c
+@@ -3234,6 +3234,10 @@ static int do_anonymous_page(struct mm_s
+ 
+       pte_unmap(page_table);
+ 
++      /* File mapping without ->vm_ops ? */
++      if (vma->vm_flags & VM_SHARED)
++              return VM_FAULT_SIGBUS;
++
+       /* Check if we need to add a guard page to the stack */
+       if (check_stack_guard_page(vma, address) < 0)
+               return VM_FAULT_SIGSEGV;
+@@ -3502,6 +3506,9 @@ static int do_linear_fault(struct mm_str
+                       - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+ 
+       pte_unmap(page_table);
++      /* The VMA was not fully populated on mmap() or missing VM_DONTEXPAND */
++      if (!vma->vm_ops->fault)
++              return VM_FAULT_SIGBUS;
+       return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
+ }
+ 
+@@ -3650,11 +3657,9 @@ static int handle_pte_fault(struct mm_st
+       entry = ACCESS_ONCE(*pte);
+       if (!pte_present(entry)) {
+               if (pte_none(entry)) {
+-                      if (vma->vm_ops) {
+-                              if (likely(vma->vm_ops->fault))
+-                                      return do_linear_fault(mm, vma, address,
++                      if (vma->vm_ops)
++                              return do_linear_fault(mm, vma, address,
+                                               pte, pmd, flags, entry);
+-                      }
+                       return do_anonymous_page(mm, vma, address,
+                                                pte, pmd, flags);
+               }

diff --git a/queue-3.14/series b/queue-3.14/series
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..ff962f6c2557e3ae4c95c53f7cf03d3b6d002cdb 100644 (file)
--- a/queue-3.14/series
+++ b/queue-3.14/series
@@ -0,0 +1 @@
+mm-avoid-setting-up-anonymous-pages-into-file-mapping.patch