From: Johan Hovold <johan@kernel.org>
Date: Thu, 25 Sep 2025 15:00:07 +0000 (+0200)
Subject: amba: tegra-ahb: Fix device leak on SMMU enable
X-Git-Tag: v6.18.3~31
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1d18fb5c71f63c761e426ce8e73e750c6a891ac8;p=thirdparty%2Fkernel%2Fstable.git

amba: tegra-ahb: Fix device leak on SMMU enable

commit 500e1368e46928f4b2259612dcabb6999afae2a6 upstream.

Make sure to drop the reference taken to the AHB platform device when
looking up its driver data while enabling the SMMU.

Note that holding a reference to a device does not prevent its driver
data from going away.

Fixes: 89c788bab1f0 ("ARM: tegra: Add SMMU enabler in AHB")
Cc: stable@vger.kernel.org	# 3.5
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/amba/tegra-ahb.c b/drivers/amba/tegra-ahb.c
index c0e8b765522dc..f23c3ed018101 100644
--- a/drivers/amba/tegra-ahb.c
+++ b/drivers/amba/tegra-ahb.c
@@ -144,6 +144,7 @@ int tegra_ahb_enable_smmu(struct device_node *dn)
 	if (!dev)
 		return -EPROBE_DEFER;
 	ahb = dev_get_drvdata(dev);
+	put_device(dev);
 	val = gizmo_readl(ahb, AHB_ARBITRATION_XBAR_CTRL);
 	val |= AHB_ARBITRATION_XBAR_CTRL_SMMU_INIT_DONE;
 	gizmo_writel(ahb, val, AHB_ARBITRATION_XBAR_CTRL);