The patch titled
mm: check for no mmaps in exit_mmap()
has been added to the -mm tree. Its filename is
mm-check-for-no-mmaps-in-exit_mmap.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mm: check for no mmaps in exit_mmap()
From: Johannes Weiner <hannes@xxxxxxxxxxx>
When dup_mmap() ooms we can end up with mm->mmap == NULL. The error
path does mmput() and unmap_vmas() gets a NULL vma which it
dereferences.
In exit_mmap() there is nothing to do at all for this case, we can
cancel the callpath right there.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reported-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 3 +++
1 file changed, 3 insertions(+)
diff -puN mm/mmap.c~mm-check-for-no-mmaps-in-exit_mmap mm/mmap.c
--- a/mm/mmap.c~mm-check-for-no-mmaps-in-exit_mmap
+++ a/mm/mmap.c
@@ -2090,6 +2090,9 @@ void exit_mmap(struct mm_struct *mm)
arch_exit_mmap(mm);
mmu_notifier_release(mm);
+ if (!mm->mmap)
+ return;
+
if (mm->locked_vm) {
vma = mm->mmap;
while (vma) {
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
mm-more-likely-reclaim-madv_sequential-mappings.patch
mm-apply_to_range-call-pte-function-with-lazy-updates.patch
vmscan-shrink_active_list-reduce-lru_lock-hold-time.patch
mm-check-for-no-mmaps-in-exit_mmap.patch
mm-check-for-no-mmaps-in-exit_mmap-fix.patch
dma_alloc_from_coherent-fix-fallback-to-generic-memory.patch
dma_alloc_coherent-clean-it-up.patch
dma-coherent-catch-oversized-requests-to-dma_alloc_from_coherent.patch
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