Re: [syzbot] [btrfs?] general protection fault in create_empty_buffers (5)

[Edward Adam Davis]

#syz test

diff --git a/block/fops.c b/block/fops.c
index 4d32785b31d9..c0cdc950d94c 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -492,6 +492,9 @@ static int blkdev_writepages(struct address_space *mapping,
 
 static int blkdev_read_folio(struct file *file, struct folio *folio)
 {
+	if (1 << READ_ONCE(folio->mapping->host->i_blkbits) > folio_size(folio))
+		return -EIO;
+
 	return block_read_full_folio(folio, blkdev_get_block);
 }