This is a note to let you know that I've just added the patch titled drbd: use after free in drbd_create_device() to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drbd-use-after-free-in-drbd_create_device.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 3d1fbfc435a5d4f281b8352462f58aee252d9442 Author: Dan Carpenter <error27@xxxxxxxxx> Date: Tue Nov 15 16:16:43 2022 +0300 drbd: use after free in drbd_create_device() [ Upstream commit a7a1598189228b5007369a9622ccdf587be0730f ] The drbd_destroy_connection() frees the "connection" so use the _safe() iterator to prevent a use after free. Fixes: b6f85ef9538b ("drbd: Iterate over all connections") Signed-off-by: Dan Carpenter <error27@xxxxxxxxx> Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@xxxxxxxxxx> Link: https://lore.kernel.org/r/Y3Jd5iZRbNQ9w6gm@kili Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 1e02cb60b65b..872e70f5b4d6 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -2804,7 +2804,7 @@ static int init_submitter(struct drbd_device *device) enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor) { struct drbd_resource *resource = adm_ctx->resource; - struct drbd_connection *connection; + struct drbd_connection *connection, *n; struct drbd_device *device; struct drbd_peer_device *peer_device, *tmp_peer_device; struct gendisk *disk; @@ -2933,7 +2933,7 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig out_idr_remove_vol: idr_remove(&connection->peer_devices, vnr); out_idr_remove_from_resource: - for_each_connection(connection, resource) { + for_each_connection_safe(connection, n, resource) { peer_device = idr_remove(&connection->peer_devices, vnr); if (peer_device) kref_put(&connection->kref, drbd_destroy_connection);