This is a note to let you know that I've just added the patch titled
nvme-tcp: can't set sk_user_data without write_lock
to the 5.13-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:
nvme-tcp-can-t-set-sk_user_data-without-write_lock.patch
and it can be found in the queue-5.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 13c4ec40c8cf5c88b10b4d22954d3cc0ac147442
Author: Maurizio Lombardi <mlombard@xxxxxxxxxx>
Date: Fri Jul 2 10:11:21 2021 +0200
nvme-tcp: can't set sk_user_data without write_lock
[ Upstream commit 0755d3be2d9bb6ea38598ccd30d6bbaa1a5c3a50 ]
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@xxxxxxxxxx>
Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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:
