diff mbox series

[4.9,087/121] fuse: dont check refcount after stealing page

Message ID 20200929105934.488374850@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg KH Sept. 29, 2020, 11 a.m. UTC 
From: Miklos Szeredi <mszeredi@redhat.com>

[ Upstream commit 32f98877c57bee6bc27f443a96f49678a2cd6a50 ]

page_count() is unstable.  Unless there has been an RCU grace period
between when the page was removed from the page cache and now, a
speculative reference may exist from the page cache.

Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/fuse/dev.c | 1 -
 1 file changed, 1 deletion(-)
diff mbox series

Patch

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index b99225e117120..f0129c033bd66 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -825,7 +825,6 @@  static int fuse_check_page(struct page *page)
 {
 	if (page_mapcount(page) ||
 	    page->mapping != NULL ||
-	    page_count(page) != 1 ||
 	    (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
 	     ~(1 << PG_locked |
 	       1 << PG_referenced |