From fed13a5478680614ba97fc87e71f16e2e197912e Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 7 Oct 2024 13:38:12 +0200 Subject: [PATCH] dm: fix a crash if blk_alloc_disk fails If blk_alloc_disk fails, the variable md->disk is set to an error value. cleanup_mapped_device will see that md->disk is non-NULL and it will attempt to access it, causing a crash on this statement "md->disk->private_data = NULL;". Signed-off-by: Mikulas Patocka Reported-by: Chenyuan Yang Closes: https://marc.info/?l=dm-devel&m=172824125004329&w=2 Cc: stable@vger.kernel.org Reviewed-by: Nitesh Shetty --- drivers/md/dm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index ff4a6b570b76..19230404d8c2 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2290,8 +2290,10 @@ static struct mapped_device *alloc_dev(int minor) * override accordingly. */ md->disk = blk_alloc_disk(NULL, md->numa_node_id); - if (IS_ERR(md->disk)) + if (IS_ERR(md->disk)) { + md->disk = NULL; goto bad; + } md->queue = md->disk->queue; init_waitqueue_head(&md->wait);