diff options
| author | Pu Lehui <pulehui@huawei.com> | 2025-05-29 15:56:48 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-06-05 21:55:41 -0700 |
| commit | b36b701bbcd9f7b24c0d98499c28895b55fdde81 (patch) | |
| tree | f0cbec1540729f53277b3cf8d3556ff6601a1941 /mm | |
| parent | 2b12d06c37fd3a394376f42f026a7478d826ed63 (diff) | |
mm: expose abnormal new_pte during move_ptes
When executing move_ptes, the new_pte must be NULL, otherwise it will be
overwritten by the old_pte, and cause the abnormal new_pte to be leaked.
In order to make this problem to be more explicit, let's add WARN_ON_ONCE
when new_pte is not NULL.
[akpm@linux-foundation.org: s/WARN_ON_ONCE/VM_WARN_ON_ONCE/]
Link: https://lkml.kernel.org/r/20250529155650.4017699-3-pulehui@huaweicloud.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/mremap.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index 83e359754961..60f6b8d0d5f0 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -237,6 +237,8 @@ static int move_ptes(struct pagetable_move_control *pmc, for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE, new_pte++, new_addr += PAGE_SIZE) { + VM_WARN_ON_ONCE(!pte_none(*new_pte)); + if (pte_none(ptep_get(old_pte))) continue; |