nvmet-tcp: Fix a possible UAF in queue intialization setup

commit d920abd1

 upstream.

From Alon:
"Due to a logical bug in the NVMe-oF/TCP subsystem in the Linux kernel,
a malicious user can cause a UAF and a double free, which may lead to
RCE (may also lead to an LPE in case the attacker already has local
privileges)."

Hence, when a queue initialization fails after the ahash requests are
allocated, it is guaranteed that the queue removal async work will be
called, hence leave the deallocation to the queue removal.

Also, be extra careful not to continue processing the socket, so set
queue rcv_state to NVMET_TCP_RECV_ERR upon a socket error.

Cc: stable@vger.kernel.org
Reported-by: Alon Zahavi <zahavi.alon@gmail.com>
Tested-by: Alon Zahavi <zahavi.alon@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Dragos-Marian Panait <dragos.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>