The patch titled
Subject: mm: fix potential anon_vma locking issue in mprotect()
has been added to the -mm tree. Its filename is
mm-fix-potential-anon_vma-locking-issue-in-mprotect.patch
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------------------------------------------------------
From: Michel Lespinasse <walken@xxxxxxxxxx>
Subject: mm: fix potential anon_vma locking issue in mprotect()
Fix an anon_vma locking issue in the following situation:
- vma has no anon_vma
- next has an anon_vma
- vma is being shrunk / next is being expanded, due to an mprotect call
We need to take next's anon_vma lock to avoid races with rmap users (such
as page migration) while next is being expanded.
Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff -puN mm/mmap.c~mm-fix-potential-anon_vma-locking-issue-in-mprotect mm/mmap.c
--- a/mm/mmap.c~mm-fix-potential-anon_vma-locking-issue-in-mprotect
+++ a/mm/mmap.c
@@ -573,8 +573,12 @@ again: remove_next = 1 + (end > next->
*/
if (vma->anon_vma && (importer || start != vma->vm_start)) {
anon_vma = vma->anon_vma;
+ VM_BUG_ON(adjust_next && next->anon_vma &&
+ anon_vma != next->anon_vma);
+ } else if (adjust_next && next->anon_vma)
+ anon_vma = next->anon_vma;
+ if (anon_vma)
anon_vma_lock(anon_vma);
- }
if (root) {
flush_dcache_mmap_lock(mapping);
_
Patches currently in -mm which might be from walken@xxxxxxxxxx are
linux-next.patch
mm-adjust-final-endif-position-in-mm-internalh.patch
mm-fix-potential-anon_vma-locking-issue-in-mprotect.patch
ipc-mqueue-remove-unnecessary-rb_init_node-calls.patch
rbtree-reference-documentation-rbtreetxt-for-usage-instructions.patch
rbtree-empty-nodes-have-no-color.patch
rbtree-empty-nodes-have-no-color-fix.patch
rbtree-fix-incorrect-rbtree-node-insertion-in-fs-proc-proc_sysctlc.patch
rbtree-move-some-implementation-details-from-rbtreeh-to-rbtreec.patch
rbtree-move-some-implementation-details-from-rbtreeh-to-rbtreec-fix.patch
rbtree-performance-and-correctness-test.patch
rbtree-performance-and-correctness-test-fix.patch
rbtree-break-out-of-rb_insert_color-loop-after-tree-rotation.patch
rbtree-adjust-root-color-in-rb_insert_color-only-when-necessary.patch
rbtree-low-level-optimizations-in-rb_insert_color.patch
rbtree-adjust-node-color-in-__rb_erase_color-only-when-necessary.patch
rbtree-adjust-root-color-in-rb_insert_color-only-when-necessary-fix.patch
rbtree-optimize-case-selection-logic-in-__rb_erase_color.patch
rbtree-low-level-optimizations-in-__rb_erase_color.patch
rbtree-coding-style-adjustments.patch
rbtree-optimize-fetching-of-sibling-node.patch
rbtree-test-fix-sparse-warning-about-64-bit-constant.patch
rbtree-add-__rb_change_child-helper-function.patch
rbtree-place-easiest-case-first-in-rb_erase.patch
rbtree-handle-1-child-recoloring-in-rb_erase-instead-of-rb_erase_color.patch
rbtree-low-level-optimizations-in-rb_erase.patch
rbtree-augmented-rbtree-test.patch
rbtree-faster-augmented-rbtree-manipulation.patch
rbtree-remove-prior-augmented-rbtree-implementation.patch
rbtree-add-rb_declare_callbacks-macro.patch
rbtree-add-prio-tree-and-interval-tree-tests.patch
mm-replace-vma-prio_tree-with-an-interval-tree.patch
kmemleak-use-rbtree-instead-of-prio-tree.patch
prio_tree-remove.patch
rbtree-move-augmented-rbtree-functionality-to-rbtree_augmentedh.patch
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