On 14/12/2025 12:53, Ma Ke wrote:

tegra_ahb_enable_smmu() utilizes driver_find_device_by_of_node() which internally calls driver_find_device() to locate the matching device. driver_find_device() increments the ref count of the found device by calling get_device(), but tegra_ahb_enable_smmu() fails to call put_device() to decrement the reference count before returning. This results in a reference count leak of the device, which may prevent the device from being properly released and cause a memory leak.

Found by code review.

Cc: stable@vger.kernel.org Fixes: 89c788bab1f0 ("ARM: tegra: Add SMMU enabler in AHB") Signed-off-by: Ma Ke make24@iscas.ac.cn

---

drivers/amba/tegra-ahb.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/amba/tegra-ahb.c b/drivers/amba/tegra-ahb.c index f23c3ed01810..3ed5cef34806 100644 --- a/drivers/amba/tegra-ahb.c +++ b/drivers/amba/tegra-ahb.c @@ -148,6 +148,7 @@ int tegra_ahb_enable_smmu(struct device_node *dn) val = gizmo_readl(ahb, AHB_ARBITRATION_XBAR_CTRL); val |= AHB_ARBITRATION_XBAR_CTRL_SMMU_INIT_DONE; gizmo_writel(ahb, val, AHB_ARBITRATION_XBAR_CTRL);

• put_device(dev); return 0; } EXPORT_SYMBOL(tegra_ahb_enable_smmu);

This has already been fixed and so this change is not needed.