Commit 3a9677b7 authored May 19, 2020 by Miklos Szeredi Committed by Greg Kroah-Hartman Oct 01, 2020

fuse: don't check refcount after stealing page



[ 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>

parent 70109a8b

fs/fuse/dev.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -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 \|