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 5.8-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-5.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bec826aa0c1f94e5b432385dddc01d7184e84e07
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 */
