From: Maurizio Lombardi <mlombard@redhat.com>

Date: Fri, 2 Jul 2021 10:11:21 +0200

Subject: [PATCH] nvme-tcp: can't set sk_user_data without write_lock

Git-commit: 0755d3be2d9bb6ea38598ccd30d6bbaa1a5c3a50

Patch-mainline: v5.14-rc1

References: git-fixes

The sk_user_data pointer is supposed to be modified only while

holding the write_lock "sk_callback_lock", otherwise

we could race with other threads and crash the kernel.

we can't take the write_lock in nvmet_tcp_state_change()

because it would cause a deadlock, but the release_work queue

will set the pointer to NULL later so we can simply remove

the assignment.

Fixes: b5332a9f3f3d ("nvmet-tcp: fix incorrect locking in state_change sk callback")

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Hannes Reinecke <hare@suse.com>

---

 drivers/nvme/target/tcp.c | 1 -

 1 file changed, 1 deletion(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c

index d8aceef83284..07ee347ea3f3 100644

--- a/drivers/nvme/target/tcp.c

+++ b/drivers/nvme/target/tcp.c

@@ -1497,7 +1497,6 @@ static void nvmet_tcp_state_change(struct sock *sk)

 	case TCP_CLOSE_WAIT:

 	case TCP_CLOSE:

 		/* FALLTHRU */

-		sk->sk_user_data = NULL;

 		nvmet_tcp_schedule_release_queue(queue);

 		break;

 	default:

-- 

2.29.2