linux-kernel - [PATCH v3] nvmet: fix uninitialized work for zero kato

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20201015015140.1061936-1-pizhenwei@bytedance.com>
Date:   Thu, 15 Oct 2020 09:51:40 +0800
From:   zhenwei pi <pizhenwei@...edance.com>
To:     hch@....de, sagi@...mberg.me, chaitanya.kulkarni@....com
Cc:     linux-nvme@...ts.infradead.org, linux-kernel@...r.kernel.org,
        pizhenwei@...edance.com
Subject: [PATCH v3] nvmet: fix uninitialized work for zero kato

Hit a warning:
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 could be reproduced easily with a keep alive time 0:
nvme connect -t tcp -n NQN -a ADDR -s PORT --keep-alive-tmo=0

Starting an uninitialized work when initiator connects with zero
kato. Althrough keep-alive timer is disabled during allocating a ctrl
(fix 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@...edance.com>
---
 drivers/nvme/target/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 25d62d867563..aafcbc424b7a 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -1126,7 +1126,8 @@ 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)
-- 
2.11.0