block: reject attempts to allocate more than DISK_MAX_PARTS partitions

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 7 insertions, 0 deletions

diff --git a/block/genhd.c b/block/genhd.c
index 2367087cdb7c..3380a1e73ea0 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1357,6 +1357,13 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
         struct gendisk *disk;
         struct disk_part_tbl *ptbl;
 
+        if (minors > DISK_MAX_PARTS) {
+                printk(KERN_ERR
+                        "block: can't allocated more than %d partitions\n",
+                        DISK_MAX_PARTS);
+                minors = DISK_MAX_PARTS;
+        }
+
         disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
         if (disk) {
                 if (!init_part_stats(&disk->part0)) {