[PATCH AUTOSEL 6.18] drm/vc4: Fix a memory leak in hang state error path

[Sasha Levin <sashal@kernel.org>]

From: Maíra Canal <mcanal@igalia.com>

[ Upstream commit 9525d169e5fd481538cf8c663cc5839e54f2e481 ]

When vc4_save_hang_state() encounters an early return condition, it
returns without freeing the previously allocated `kernel_state`,
leaking memory.

Add the missing kfree() calls by consolidating the early return paths
into a single place.

Fixes: 214613656b51 ("drm/vc4: Add an interface for capturing the GPU state after a hang.")
Reviewed-by: Melissa Wen <mwen@igalia.com>
Link: https://patch.msgid.link/20260330-vc4-misc-fixes-v1-3-92defc940a29@igalia.com
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

LLM Generated explanations, may be completely bogus:

Error: Failed to generate final synthesis

 drivers/gpu/drm/vc4/vc4_gem.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c
index 6238630e46793..6887631f2d8be 100644
--- a/drivers/gpu/drm/vc4/vc4_gem.c
+++ b/drivers/gpu/drm/vc4/vc4_gem.c
@@ -170,10 +170,8 @@ vc4_save_hang_state(struct drm_device *dev)
 	spin_lock_irqsave(&vc4->job_lock, irqflags);
 	exec[0] = vc4_first_bin_job(vc4);
 	exec[1] = vc4_first_render_job(vc4);
-	if (!exec[0] && !exec[1]) {
-		spin_unlock_irqrestore(&vc4->job_lock, irqflags);
-		return;
-	}
+	if (!exec[0] && !exec[1])
+		goto err_free_state;
 
 	/* Get the bos from both binner and renderer into hang state. */
 	state->bo_count = 0;
@@ -190,10 +188,8 @@ vc4_save_hang_state(struct drm_device *dev)
 	kernel_state->bo = kcalloc(state->bo_count,
 				   sizeof(*kernel_state->bo), GFP_ATOMIC);
 
-	if (!kernel_state->bo) {
-		spin_unlock_irqrestore(&vc4->job_lock, irqflags);
-		return;
-	}
+	if (!kernel_state->bo)
+		goto err_free_state;
 
 	k = 0;
 	for (i = 0; i < 2; i++) {
@@ -285,6 +281,12 @@ vc4_save_hang_state(struct drm_device *dev)
 		vc4->hang_state = kernel_state;
 		spin_unlock_irqrestore(&vc4->job_lock, irqflags);
 	}
+
+	return;
+
+err_free_state:
+	spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+	kfree(kernel_state);
 }
 
 static void
-- 
2.53.0