From: Li Xinhai <lixinhai.lxh@gmail.com>
To: linux-mm@kvack.org
Cc: akpm@linux-foundation.org,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Matthew Wilcox <willy@infradead.org>,
Johannes Weiner <hannes@cmpxchg.org>
Subject: [PATCH 3/3] mm: set vm_next and vm_prev to NULL in vm_area_dup()
Date: Sat, 8 Feb 2020 08:35:28 +0000 [thread overview]
Message-ID: <1581150928-3214-4-git-send-email-lixinhai.lxh@gmail.com> (raw)
In-Reply-To: <1581150928-3214-1-git-send-email-lixinhai.lxh@gmail.com>
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>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
---
kernel/fork.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index 1bbd49a..eb3a148 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;
}
@@ -561,7 +562,6 @@ 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);
--
1.8.3.1
next prev parent reply other threads:[~2020-02-08 8:37 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-08 8:35 [PATCH 0/3] mm: Fix misuse of parent anon_vma in dup_mmap path Li Xinhai
2020-02-08 8:35 ` [PATCH 1/3] mm: don't prepare anon_vma if vma has VM_WIPEONFORK Li Xinhai
2020-02-08 8:53 ` Li Xinhai
2020-04-02 13:45 ` Kirill A. Shutemov
2020-02-08 8:35 ` [PATCH 2/3] Revert "mm/rmap.c: reuse mergeable anon_vma as parent when fork" Li Xinhai
2020-04-02 13:59 ` Kirill A. Shutemov
2020-04-03 3:08 ` Li Xinhai
2020-04-05 1:26 ` Li Xinhai
2020-02-08 8:35 ` Li Xinhai [this message]
2020-04-02 14:07 ` [PATCH 3/3] mm: set vm_next and vm_prev to NULL in vm_area_dup() Kirill A. Shutemov
2020-02-10 0:52 ` [PATCH 0/3] mm: Fix misuse of parent anon_vma in dup_mmap path Andrew Morton
2020-02-10 2:15 ` Li Xinhai
2020-04-20 12:06 ` Michal Hocko
2020-04-21 3:53 ` Li Xinhai
2020-04-21 7:26 ` Michal Hocko
2020-04-02 1:25 ` Andrew Morton
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