This is a note to let you know that I've just added the patch titled nvmet: fix uninitialized work for zero kato to the 4.9-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: nvmet-fix-uninitialized-work-for-zero-kato.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b7f41874fd12668c3f41d5643ca605f018914005 Author: zhenwei pi <pizhenwei@xxxxxxxxxxxxx> Date: Thu Oct 15 09:51:40 2020 +0800 nvmet: fix uninitialized work for zero kato [ Upstream commit 85bd23f3dc09a2ae9e56885420e52c54bf983713 ] When connecting a controller with a zero kato value using the following command line nvme connect -t tcp -n NQN -a ADDR -s PORT --keep-alive-tmo=0 the warning below can be reproduced: WARNING: CPU: 1 PID: 241 at kernel/workqueue.c:1627 __queue_delayed_work+0x6d/0x90 with trace: mod_delayed_work_on+0x59/0x90 nvmet_update_cc+0xee/0x100 [nvmet] nvmet_execute_prop_set+0x72/0x80 [nvmet] nvmet_tcp_try_recv_pdu+0x2f7/0x770 [nvmet_tcp] nvmet_tcp_io_work+0x63f/0xb2d [nvmet_tcp] ... This is caused by queuing up an uninitialized work. Althrough the keep-alive timer is disabled during allocating the controller (fixed in 0d3b6a8d213a), ka_work still has a chance to run (called by nvmet_start_ctrl). Fixes: 0d3b6a8d213a ("nvmet: Disable keep-alive timer when kato is cleared to 0h") Signed-off-by: zhenwei pi <pizhenwei@xxxxxxxxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c index 63b87a8472762..4b58f352c0c93 100644 --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -591,7 +591,8 @@ static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl) * in case a host died before it enabled the controller. Hence, simply * reset the keep alive timer when the controller is enabled. */ - mod_delayed_work(system_wq, &ctrl->ka_work, ctrl->kato * HZ); + if (ctrl->kato) + mod_delayed_work(system_wq, &ctrl->ka_work, ctrl->kato * HZ); } static void nvmet_clear_ctrl(struct nvmet_ctrl *ctrl)