[PATCH] media: mali-c55: fix resource leaks in probe and remove

[David Carlier <devnexen@gmail.com>]

mali_c55_probe() calls of_reserved_mem_device_init() to associate
reserved memory regions with the device. This function allocates a
struct rmem_assigned_device and adds it to a global linked list, which
must be explicitly released via of_reserved_mem_device_release() — there
is no devm variant of this API.

However, neither the probe error paths nor mali_c55_remove() called
of_reserved_mem_device_release(). Any probe failure after the
of_reserved_mem_device_init() call, as well as every normal device
removal, leaked the reserved memory association on the global list.

Additionally, pm_runtime_enable() called during probe was never undone
in mali_c55_remove(), leaving the device's runtime PM state enabled
after the driver is unbound. The probe error path had a related issue:
when mali_c55_media_frameworks_init() failed, the goto target jumped
directly to err_free_context_registers, skipping pm_runtime_disable()
despite pm_runtime having already been enabled earlier in the function.

Fix these issues by:
 - Adding an err_release_mem label at the end of the error chain so all
   post-init failure paths release the reserved memory association.
 - Splitting pm_runtime_disable() into its own err_runtime_disable label
   so the media frameworks init failure correctly unwinds it.
 - Adding of_reserved_mem_device_release() and pm_runtime_disable() to
   mali_c55_remove(), with the teardown order mirroring probe in
   reverse.

Fixes: d5f281f3dd29 ("media: mali-c55: Add Mali-C55 ISP driver")
Signed-off-by: David Carlier <devnexen@gmail.com>
---
 .../media/platform/arm/mali-c55/mali-c55-core.c  | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-core.c b/drivers/media/platform/arm/mali-c55/mali-c55-core.c
index c1a562cd214e..de895b69d786 100644
--- a/drivers/media/platform/arm/mali-c55/mali-c55-core.c
+++ b/drivers/media/platform/arm/mali-c55/mali-c55-core.c
@@ -806,8 +806,10 @@ static int mali_c55_probe(struct platform_device *pdev)
 	vb2_dma_contig_set_max_seg_size(dev, UINT_MAX);
 
 	ret = __mali_c55_power_on(mali_c55);
-	if (ret)
-		return dev_err_probe(dev, ret, "failed to power on\n");
+	if (ret) {
+		dev_err_probe(dev, ret, "failed to power on\n");
+		goto err_release_mem;
+	}
 
 	ret = mali_c55_check_hwcfg(mali_c55);
 	if (ret)
@@ -826,7 +828,7 @@ static int mali_c55_probe(struct platform_device *pdev)
 
 	ret = mali_c55_media_frameworks_init(mali_c55);
 	if (ret)
-		goto err_free_context_registers;
+		goto err_runtime_disable;
 
 	pm_runtime_idle(&pdev->dev);
 
@@ -841,11 +843,13 @@ static int mali_c55_probe(struct platform_device *pdev)
 
 err_deinit_media_frameworks:
 	mali_c55_media_frameworks_deinit(mali_c55);
+err_runtime_disable:
 	pm_runtime_disable(&pdev->dev);
-err_free_context_registers:
 	kfree(mali_c55->context.registers);
 err_power_off:
 	__mali_c55_power_off(mali_c55);
+err_release_mem:
+	of_reserved_mem_device_release(dev);
 
 	return ret;
 }
@@ -854,8 +858,10 @@ static void mali_c55_remove(struct platform_device *pdev)
 {
 	struct mali_c55 *mali_c55 = platform_get_drvdata(pdev);
 
-	kfree(mali_c55->context.registers);
 	mali_c55_media_frameworks_deinit(mali_c55);
+	pm_runtime_disable(&pdev->dev);
+	kfree(mali_c55->context.registers);
+	of_reserved_mem_device_release(&pdev->dev);
 }
 
 static const struct of_device_id mali_c55_of_match[] = {
-- 
2.53.0