From 6d2eb0f1168c709a7c8fd62f2c90f6643e39609c Mon Sep 17 00:00:00 2001 From: Anthony Romano Date: Fri, 24 Jun 2016 14:48:43 -0700 Subject: [PATCH] tmpfs: don't undo fallocate past its last page 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 Cc: Vlastimil Babka Cc: Hugh Dickins Cc: Brandon Philips Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Willy Tarreau --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/shmem.c b/mm/shmem.c index 4e4a7349c5cd..e163e40b0bb5 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; } -- 2.20.1