From 1d3255b4d9f8c592df8e0cfac8078e5148510887 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: Greg Kroah-Hartman --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/shmem.c b/mm/shmem.c index ea5a70cfc1d8..80297712314e 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2155,7 +2155,7 @@ 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; } -- 2.11.0