From: Anthony Romano Date: Fri, 24 Jun 2016 21:48:43 +0000 (-0700) Subject: tmpfs: don't undo fallocate past its last page X-Git-Tag: firefly_0821_release~176^2~4^2~37^2~4 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1d3255b4d9f8c592df8e0cfac8078e5148510887;p=firefly-linux-kernel-4.4.55.git 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 --- 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; }