[PATCH 5.4 52/57] nvme: prevent double free in nvme_alloc_ns() error handling

Greg Kroah-Hartman
2020-05-04T18:04:37Z

From: Niklas Cassel <niklas.cassel@wdc.com>

commit 132be62387c7a72a38872676c18b0dfae264adb8 upstream.

When jumping to the out_put_disk label, we will call put_disk(), which will
trigger a call to disk_release(), which calls blk_put_queue().

Later in the cleanup code, we do blk_cleanup_queue(), which will also call
blk_put_queue().

Putting the queue twice is incorrect, and will generate a KASAN splat.

Set the disk->queue pointer to NULL, before calling put_disk(), so that the
first call to blk_put_queue() will not free the queue.

The second call to blk_put_queue() uses another pointer to the same queue,
so this call will still free the queue.

Fixes: 85136c010285 ("lightnvm: simplify geometry enumeration")
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/nvme/host/core.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3566,6 +3566,8 @@ static int nvme_alloc_ns(struct nvme_ctr

return 0;
out_put_disk:
+ /* prevent double queue cleanup */
+ ns->disk->queue = NULL;
put_disk(ns->disk);
out_unlink_ns:
mutex_lock(&ctrl->subsys->lock);