This is a note to let you know that I've just added the patch titled ramfs: fix nommu mmap with gaps in the page cache to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ramfs-fix-nommu-mmap-with-gaps-in-the-page-cache.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 26d1ddea4b6879d1534cf7cfdd938231ce764ec6 Author: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Date: Thu Oct 15 20:13:04 2020 -0700 ramfs: fix nommu mmap with gaps in the page cache [ Upstream commit 50b7d85680086126d7bd91dae81d57d4cb1ab6b7 ] ramfs needs to check that pages are both physically contiguous and contiguous in the file. If the page cache happens to have, eg, page A for index 0 of the file, no page for index 1, and page A+1 for index 2, then an mmap of the first two pages of the file will succeed when it should fail. Fixes: 642fb4d1f1dd ("[PATCH] NOMMU: Provide shared-writable mmap support on ramfs") Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: David Howells <dhowells@xxxxxxxxxx> Link: https://lkml.kernel.org/r/20200914122239.GO6583@xxxxxxxxxxxxxxxxxxxx Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c index 4146954549560..355523f4a4bf3 100644 --- a/fs/ramfs/file-nommu.c +++ b/fs/ramfs/file-nommu.c @@ -224,7 +224,7 @@ static unsigned long ramfs_nommu_get_unmapped_area(struct file *file, if (!pages) goto out_free; - nr = find_get_pages(inode->i_mapping, &pgoff, lpages, pages); + nr = find_get_pages_contig(inode->i_mapping, pgoff, lpages, pages); if (nr != lpages) goto out_free_pages; /* leave if some pages were missing */