diff options
| author | Muchun Song <songmuchun@bytedance.com> | 2022-03-22 14:42:05 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-15 20:18:53 +0200 |
| commit | 72dd0487237d8e801ae9f538baeb58b7a0e6d8aa (patch) | |
| tree | 20b4020ff660b14a2cc6ed779d4f7dc82723704c | |
| parent | e36b476a829c61f69a0729029104513a89a5bef4 (diff) | |
mm: shmem: fix missing cache flush in shmem_mfill_atomic_pte()
commit 19b482c29b6f3805f1d8e93015847b89e2f7f3b1 upstream.
userfaultfd calls shmem_mfill_atomic_pte() which does not do any cache
flushing for the target page. Then the target page will be mapped to
the user space with a different address (user address), which might have
an alias issue with the kernel address used to copy the data from the
user to. Insert flush_dcache_page() in non-zero-page case. And replace
clear_highpage() with clear_user_highpage() which already considers the
cache maintenance.
Link: https://lkml.kernel.org/r/20220210123058.79206-6-songmuchun@bytedance.com
Fixes: 8d1039634206 ("userfaultfd: shmem: add shmem_mfill_zeropage_pte for userfaultfd support")
Fixes: 4c27fe4c4c84 ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lars Persson <lars.persson@axis.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | mm/shmem.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 1609a8daba26..342d1bc72867 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2394,8 +2394,10 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, /* don't free the page */ goto out_unacct_blocks; } + + flush_dcache_page(page); } else { /* ZEROPAGE */ - clear_highpage(page); + clear_user_highpage(page, dst_addr); } } else { page = *pagep; |