From: Anthony Romano <anthony.rom...@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.rom...@coreos.com
Signed-off-by: Anthony Romano <anthony.rom...@coreos.com>
Cc: Vlastimil Babka <vba...@suse.cz>
Cc: Hugh Dickins <hu...@google.com>
Cc: Brandon Philips <bran...@ifup.co>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Willy Tarreau <w...@1wt.eu>
---
mm/shmem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 4e4a734..e163e40 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1950,7 +1950,7 @@ static long shmem_fallocate(struct file *file, int mode,
loff_t offset,
/* Remove the !PageUptodate pages we added */
shmem_undo_range(inode,
(loff_t)start << PAGE_CACHE_SHIFT,
- (loff_t)index << PAGE_CACHE_SHIFT, true);
+ ((loff_t)index << PAGE_CACHE_SHIFT) - 1, true);
goto undone;
}
--
2.8.0.rc2.1.gbe9624a
