The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 781e14eaa7d168dc07d2a2eea5c55831a5bb46f3 Mon Sep 17 00:00:00 2001

From: Mika Westerberg mika.westerberg@linux.intel.com Date: Wed, 10 Feb 2021 16:06:33 +0200 Subject: [PATCH] thunderbolt: Initialize HopID IDAs in tb_switch_alloc()

If there is a failure before the tb_switch_add() is called the switch object is released by tb_switch_release() but at that point HopID IDAs have not yet been initialized. So we see splat like this:

BUG: spinlock bad magic on CPU#2, kworker/u8:5/115 ... Workqueue: thunderbolt0 tb_handle_hotplug Call Trace: dump_stack+0x97/0xdc ? spin_bug+0x9a/0xa7 do_raw_spin_lock+0x68/0x98 _raw_spin_lock_irqsave+0x3f/0x5d ida_destroy+0x4f/0x127 tb_switch_release+0x6d/0xfd device_release+0x2c/0x7d kobject_put+0x9b/0xbc tb_handle_hotplug+0x278/0x452 process_one_work+0x1db/0x396 worker_thread+0x216/0x375 kthread+0x14d/0x155 ? pr_cont_work+0x58/0x58 ? kthread_blkcg+0x2e/0x2e ret_from_fork+0x1f/0x40

Fix this by always initializing HopID IDAs in tb_switch_alloc().

Fixes: 0b2863ac3cfd ("thunderbolt: Add functions for allocating and releasing HopIDs") Cc: stable@vger.kernel.org Reported-by: Chiranjeevi Rapolu chiranjeevi.rapolu@intel.com Signed-off-by: Mika Westerberg mika.westerberg@linux.intel.com

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index b63fecca6c2a..2a95b4ce06c0 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -768,12 +768,6 @@ static int tb_init_port(struct tb_port *port)

tb_dump_port(port->sw->tb, &port->config);

- /* Control port does not need HopID allocation */ - if (port->port) { - ida_init(&port->in_hopids); - ida_init(&port->out_hopids); - } - INIT_LIST_HEAD(&port->list); return 0;

@@ -1842,10 +1836,8 @@ static void tb_switch_release(struct device *dev) dma_port_free(sw->dma_port);

tb_switch_for_each_port(sw, port) { - if (!port->disabled) { - ida_destroy(&port->in_hopids); - ida_destroy(&port->out_hopids); - } + ida_destroy(&port->in_hopids); + ida_destroy(&port->out_hopids); }

kfree(sw->uuid); @@ -2025,6 +2017,12 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent, /* minimum setup for tb_find_cap and tb_drom_read to work */ sw->ports[i].sw = sw; sw->ports[i].port = i; + + /* Control port does not need HopID allocation */ + if (i) { + ida_init(&sw->ports[i].in_hopids); + ida_init(&sw->ports[i].out_hopids); + } }

ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_PLUG_EVENTS);