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

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

[Maurizio Lombardi]

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>
---
 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:
-- 
2.27.0


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

[Christoph Hellwig]

Thanks,

applied to nvme-5.14.

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