Attempting to unshare extents beyond EOF will trigger the need zeroing case, which in turn triggers a warning. Therefore, let's skip the unshare process if extents are beyond EOF. Reported-and-tested-by: syzbot+296b1c84b9cbf306e5a0@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=296b1c84b9cbf306e5a0 Fixes: 32a38a499104 ("iomap: use write_begin to read pages to unshare") Inspired-by: Dave Chinner <david@xxxxxxxxxxxxx> Signed-off-by: Julian Sun <sunjunchao2870@xxxxxxxxx> --- fs/iomap/buffered-io.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index f420c53d86ac..8898d5ec606f 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1340,6 +1340,9 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter) /* don't bother with holes or unwritten extents */ if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN) return length; + /* don't try to unshare any extents beyond EOF. */ + if (pos > i_size_read(iter->inode)) + return length; do { struct folio *folio; -- 2.39.2
