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| author |   Li Xinhai <lixinhai.lxh@gmail.com> | 2020-04-06 20:03:39 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-07 10:43:37 -0700 |
| commit | e39a4b332df69f6850efda5ce6d932ef14a39042 (patch) | |
| tree | bb60f7247fc676a15dacb899ca15a02881535877 /kernel | |
| parent | Revert "mm/rmap.c: reuse mergeable anon_vma as parent when fork" (diff) | |
| download | linux-dev-e39a4b332df69f6850efda5ce6d932ef14a39042.tar.xz linux-dev-e39a4b332df69f6850efda5ce6d932ef14a39042.zip | |
mm: set vm_next and vm_prev to NULL in vm_area_dup()
Set ->vm_next and ->vm_prev to NULL to prevent potential misuse from the
new duplicated vma.
Currently, only in fork path there are misuse for handling anon_vma. No
other bugs been revealed with this patch applied.
Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Link: http://lkml.kernel.org/r/1581150928-3214-4-git-send-email-lixinhai.lxh@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/fork.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index d3a5915d3cfe..4385f3d639f2 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -361,6 +361,7 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig) if (new) { *new = *orig; INIT_LIST_HEAD(&new->anon_vma_chain); + new->vm_next = new->vm_prev = NULL; } return new; } @@ -562,7 +563,6 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, } else if (anon_vma_fork(tmp, mpnt)) goto fail_nomem_anon_vma_fork; tmp->vm_flags &= ~(VM_LOCKED | VM_LOCKONFAULT); - tmp->vm_next = tmp->vm_prev = NULL; file = tmp->vm_file; if (file) { struct inode *inode = file_inode(file); |