diff mbox series

[AUTOSEL,03/14] mm: hugetlb: fix missing cache flush in copy_huge_page_from_user()

Message ID 20220428154222.1230793-3-gregkh@linuxfoundation.org
State New
Headers show
Series [AUTOSEL,01/14] mm: fix invalid page pointer returned with FOLL_PIN gups | expand

Commit Message

Greg KH April 28, 2022, 3:42 p.m. UTC 
From: Muchun Song <songmuchun@bytedance.com>

commit e763243cc6cb1fcc720ec58cfd6e7c35ae90a479 upstream.

userfaultfd calls copy_huge_page_from_user() 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.

Fix this issue by flushing dcache in copy_huge_page_from_user().

Link: https://lkml.kernel.org/r/20220210123058.79206-4-songmuchun@bytedance.com
Fixes: fa4d75c1de13 ("userfaultfd: hugetlbfs: add copy_huge_page_from_user for hugetlb 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>
---
 mm/memory.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/mm/memory.c b/mm/memory.c
index b69afe3dd597..886925d97759 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5475,6 +5475,8 @@  long copy_huge_page_from_user(struct page *dst_page,
 		if (rc)
 			break;
 
+		flush_dcache_page(subpage);
+
 		cond_resched();
 	}
 	return ret_val;