[PATCH] i3c: master: adi: initialize the lock before enabling interrupts

[Runyu Xiao]

adi_i3c_master_probe() requests the IRQ and unmasks REG_IRQ_PENDING_CMDR
before the controller's IBI state, transfer queue list and transfer
queue lock are initialized.  A pending CMDR interrupt can therefore run
adi_i3c_master_irq() and take master->xferqueue.lock before the dynamic
lock has been initialized.

This issue was found by our static analysis tool and then manually
reviewed against the current tree.

The grounded PoC kept the probe ordering and the IRQ path
adi_i3c_master_probe() -> adi_i3c_master_irq() -> xferqueue.lock, with a
pending CMDR interrupt arriving after REG_IRQ_PENDING_CMDR is unmasked.
Lockdep reported:

  INFO: trying to register non-static key.
  you didn't initialize this object before use?
  lock_acquire+0xbb/0x290
  _raw_spin_lock_irqsave+0x36/0x60
  adi_i3c_master_irq+0x32/0x56 [vuln_msv]
  adi_i3c_master_probe+0x5a/0xf47 [vuln_msv]

Initialize the transfer queue and IBI state before requesting and
unmasking the IRQ.

Fixes: a79ac2cdc91d ("i3c: master: Add driver for Analog Devices I3C Controller IP")
Cc: stable at vger.kernel.org
Signed-off-by: Runyu Xiao <runyu.xiao at seu.edu.cn>
---
 drivers/i3c/master/adi-i3c-master.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/i3c/master/adi-i3c-master.c b/drivers/i3c/master/adi-i3c-master.c
index 82ac0b3d057a..cf873d46e10f 100644
--- a/drivers/i3c/master/adi-i3c-master.c
+++ b/drivers/i3c/master/adi-i3c-master.c
@@ -967,17 +967,9 @@ static int adi_i3c_master_probe(struct platform_device *pdev)
 	writel(0x00, master->regs + REG_ENABLE);
 	writel(0x00, master->regs + REG_IRQ_MASK);
 
-	ret = devm_request_irq(&pdev->dev, irq, adi_i3c_master_irq, 0,
-			       dev_name(&pdev->dev), master);
-	if (ret)
-		return ret;
-
 	platform_set_drvdata(pdev, master);
 
 	master->free_rr_slots = GENMASK(ADI_MAX_DEVS, 1);
-
-	writel(REG_IRQ_PENDING_CMDR, master->regs + REG_IRQ_MASK);
-
 	spin_lock_init(&master->ibi.lock);
 	master->ibi.num_slots = 15;
 	master->ibi.slots = devm_kcalloc(&pdev->dev, master->ibi.num_slots,
@@ -989,6 +981,13 @@ static int adi_i3c_master_probe(struct platform_device *pdev)
 	spin_lock_init(&master->xferqueue.lock);
 	INIT_LIST_HEAD(&master->xferqueue.list);
 
+	ret = devm_request_irq(&pdev->dev, irq, adi_i3c_master_irq, 0,
+			       dev_name(&pdev->dev), master);
+	if (ret)
+		return ret;
+
+	writel(REG_IRQ_PENDING_CMDR, master->regs + REG_IRQ_MASK);
+
 	return i3c_master_register(&master->base, &pdev->dev,
 				   &adi_i3c_master_ops, false);
 }
-- 
2.34.1