[PATCH] nvme-tcp: don't access released socket during error recovery

[Belanger, Martin]

> On 2/26/23 13:42, Akinobu Mita wrote:
> > While the error recovery work is temporarily failing reconnect
> > attempts, running the 'nvme list' command causes a kernel NULL pointer
> > dereference by calling getsockname() with a released socket.
> >
> > During error recovery work, the nvme tcp socket is released and a new
> > one created, so it is not safe to access the socket without proper check.
> >
> > Signed-off-by: Akinobu Mita <akinobu.mita at gmail.com>
> > Fixes: 02c57a82c008 ("nvme-tcp: print actual source IP address through
> > sysfs "address" attr")
> > Cc: Martin Belanger <martin.belanger at dell.com>
> > Cc: Sagi Grimberg <sagi at grimberg.me>
> > Cc: Chaitanya Kulkarni <kch at nvidia.com>
> > Cc: Christoph Hellwig <hch at lst.de>
> > Cc: Keith Busch <kbusch at kernel.org>
> > Cc: Jens Axboe <axboe at fb.com>
> > Cc: Hannes Reinecke <hare at suse.de>
> > ---
> >   drivers/nvme/host/tcp.c | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index
> > 1955c0ec209e..7723a4989524 100644
> > --- a/drivers/nvme/host/tcp.c
> > +++ b/drivers/nvme/host/tcp.c
> > @@ -2492,6 +2492,10 @@ static int nvme_tcp_get_address(struct
> > nvme_ctrl *ctrl, char *buf, int size)
> >
> >   	len = nvmf_get_address(ctrl, buf, size);
> >
> > +	mutex_lock(&queue->queue_lock);
> > +
> > +	if (!test_bit(NVME_TCP_Q_LIVE, &queue->flags))
> > +		goto done;
> >   	ret = kernel_getsockname(queue->sock, (struct sockaddr
> *)&src_addr);
> >   	if (ret > 0) {
> >   		if (len > 0)
> > @@ -2499,6 +2503,8 @@ static int nvme_tcp_get_address(struct
> nvme_ctrl *ctrl, char *buf, int size)
> >   		len += scnprintf(buf + len, size - len, "%ssrc_addr=%pISc\n",
> >   				(len) ? "," : "", &src_addr);
> >   	}
> > +done:
> > +	mutex_unlock(&queue->queue_lock);
> >
> >   	return len;
> >   }
> Reviewed-by: Hannes Reinecke <hare at suse.de>
Reviewed-by: Martin Belanger <martin.belanger at dell.com>