nvme: fix NULL derefence in nvme_ctrl_fast_io_fail_tmo_show/store

Adding entry for dev_attr_fast_io_fail_tmo to avoid the kernel crash
while reading and writing the fast_io_fail_tmo.

Fixes: 09fbed636382 (nvme: export fast_io_fail_tmo to sysfs)
Signed-off-by: Gopal Tiwari <gtiwari@redhat.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 288ac47ff5b47091db5c7d91d7ba7f029855fa9a..40f08e6325ef04358c5ad60d3f12825bacb1887a 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3379,6 +3379,8 @@ static umode_t nvme_dev_attrs_are_visible(struct kobject *kobj,
                return 0;
        if (a == &dev_attr_reconnect_delay.attr && !ctrl->opts)
                return 0;
+       if (a == &dev_attr_fast_io_fail_tmo.attr && !ctrl->opts)
+               return 0;
 
        return a->mode;
 }