From b9b4bb26af017dbe930cd4df7f9b2fc3a0497bfe Mon Sep 17 00:00:00 2001 From: Anthony Romano Date: Fri, 24 Jun 2016 14:48:43 -0700 Subject: tmpfs: don't undo fallocate past its last page 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 Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds diff --git a/mm/shmem.c b/mm/shmem.c index a361449..24463b6 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2227,7 +2227,7 @@ 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_SHIFT, - (loff_t)index << PAGE_SHIFT, true); + ((loff_t)index << PAGE_SHIFT) - 1, true); goto undone; } -- cgit v0.10.2