From: Xiaomeng Tong xiam0nd.tong@gmail.com
commit ae4d37b5df749926891583d42a6801b5da11e3c1 upstream.
The bug is here: idr_remove(&connection->peer_devices, vnr);
If the previous for_each_connection() don't exit early (no goto hit inside the loop), the iterator 'connection' after the loop will be a bogus pointer to an invalid structure object containing the HEAD (&resource->connections). As a result, the use of 'connection' above will lead to a invalid memory access (including a possible invalid free as idr_remove could call free_layer).
The original intention should have been to remove all peer_devices, but the following lines have already done the work. So just remove this line and the unneeded label, to fix this bug.
Cc: stable@vger.kernel.org Fixes: c06ece6ba6f1b ("drbd: Turn connection->volumes into connection->peer_devices") Signed-off-by: Xiaomeng Tong xiam0nd.tong@gmail.com Reviewed-by: Christoph Böhmwalder christoph.boehmwalder@linbit.com Reviewed-by: Lars Ellenberg lars.ellenberg@linbit.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/block/drbd/drbd_main.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
--- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -2793,12 +2793,12 @@ enum drbd_ret_code drbd_create_device(st
if (init_submitter(device)) { err = ERR_NOMEM; - goto out_idr_remove_vol; + goto out_idr_remove_from_resource; }
err = add_disk(disk); if (err) - goto out_idr_remove_vol; + goto out_idr_remove_from_resource;
/* inherit the connection state */ device->state.conn = first_connection(resource)->cstate; @@ -2812,8 +2812,6 @@ enum drbd_ret_code drbd_create_device(st drbd_debugfs_device_add(device); return NO_ERROR;
-out_idr_remove_vol: - idr_remove(&connection->peer_devices, vnr); out_idr_remove_from_resource: for_each_connection(connection, resource) { peer_device = idr_remove(&connection->peer_devices, vnr);