Patch "tmpfs: don't undo fallocate past its last page" has been added to the 4.6-stable tree

Patch "tmpfs: don't undo fallocate past its last page" has been added to the 4.6-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    tmpfs: don't undo fallocate past its last page

to the 4.6-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:
     tmpfs-don-t-undo-fallocate-past-its-last-page.patch
and it can be found in the queue-4.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From b9b4bb26af017dbe930cd4df7f9b2fc3a0497bfe Mon Sep 17 00:00:00 2001
From: Anthony Romano <anthony.romano@coreos.com>
Date: Fri, 24 Jun 2016 14:48:43 -0700
Subject: tmpfs: don't undo fallocate past its last page

From: Anthony Romano <anthony.romano@coreos.com>

commit b9b4bb26af017dbe930cd4df7f9b2fc3a0497bfe upstream.

When fallocate is interrupted it will undo a range that extends one byte
past its range of allocated pages.  This can corrupt an in-use page by
zeroing out its first byte.  Instead, undo using the inclusive byte
range.

Fixes: 1635f6a74152f1d ("tmpfs: undo fallocation on failure")
Link: http://lkml.kernel.org/r/1462713387-16724-1-git-send-email-anthony.romano@coreos.com
Signed-off-by: Anthony Romano <anthony.romano@coreos.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Brandon Philips <brandon@ifup.co>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 mm/shmem.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2238,7 +2238,7 @@ static long shmem_fallocate(struct file
 			/* Remove the !PageUptodate pages we added */
 			shmem_undo_range(inode,
 				(loff_t)start << PAGE_SHIFT,
-				(loff_t)index << PAGE_SHIFT, true);
+				((loff_t)index << PAGE_SHIFT) - 1, true);
 			goto undone;
 		}
 


Patches currently in stable-queue which might be from anthony.romano@coreos.com are

queue-4.6/tmpfs-don-t-undo-fallocate-past-its-last-page.patch