genirq/msi: Take the per-device MSI lock before validating the control structure

Calling msi_ctrl_valid() ultimately results in calling
msi_get_device_domain(), which requires holding the device MSI lock.

However, in msi_domain_populate_irqs() the lock is taken right after having
called msi_ctrl_valid(), which is just a tad too late.

Take the lock before invoking msi_ctrl_valid().

Fixes: 40742716f294 ("genirq/msi: Make msi_add_simple_msi_descs() device domain aware")
Reported-by: "Russell King (Oracle)" <linux@armlinux.org.uk>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/Y/Opu6ETe3ZzZ/8E@shell.armlinux.org.uk
Link: https://lore.kernel.org/r/20230220190101.314446-1-maz@kernel.org

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 783a3e6..13d9649 100644 (file)
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -1084,10 +1084,13 @@ int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
        struct xarray *xa;
        int ret, virq;
 
-       if (!msi_ctrl_valid(dev, &ctrl))
-               return -EINVAL;
-
        msi_lock_descs(dev);
+
+       if (!msi_ctrl_valid(dev, &ctrl)) {
+               ret = -EINVAL;
+               goto unlock;
+       }
+
        ret = msi_domain_add_simple_msi_descs(dev, &ctrl);
        if (ret)
                goto unlock;