diff mbox series

[18/19] mm/khugepaged.c: fix khugepaged's request size in collapse_file

Message ID 20200904233616.8nQR2-R8H%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [01/19] memcg: fix use-after-free in uncharge_batch | expand

Commit Message

Andrew Morton Sept. 4, 2020, 11:36 p.m. UTC
From: David Howells <dhowells@redhat.com>
Subject: mm/khugepaged.c: fix khugepaged's request size in collapse_file

collapse_file() in khugepaged passes PAGE_SIZE as the number of pages to
be read to page_cache_sync_readahead().  The intent was probably to read a
single page.  Fix it to use the number of pages to the end of the window

Link: https://lkml.kernel.org/r/20200903140844.14194-2-willy@infradead.org
Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Yang Shi <shy828301@gmail.com>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

 mm/khugepaged.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series


--- a/mm/khugepaged.c~fix-khugepageds-request-size-in-collapse_file
+++ a/mm/khugepaged.c
@@ -1709,7 +1709,7 @@  static void collapse_file(struct mm_stru
 				page_cache_sync_readahead(mapping, &file->f_ra,
 							  file, index,
-							  PAGE_SIZE);
+							  end - index);
 				/* drain pagevecs to help isolate_lru_page() */
 				page = find_lock_page(mapping, index);