[PATCH] drm/bridge: samsung-dsim: Fix memory leak in error path

[Osama Abdelkader]

In samsung_dsim_host_attach(), drm_bridge_add() is called to add the
bridge. However, if samsung_dsim_register_te_irq() or
pdata->host_ops->attach() fails afterwards, the function returns
without removing the bridge, causing a memory leak.

Fix this by adding proper error handling with goto labels to ensure
drm_bridge_remove() is called in all error paths. Also ensure that
samsung_dsim_unregister_te_irq() is called if the attach operation
fails after the TE IRQ has been registered.

samsung_dsim_unregister_te_irq() function is moved without changes
to be before samsung_dsim_host_attach() to avoid forward declaration.

Fixes: e7447128ca4a ("drm: bridge: Generalize Exynos-DSI driver into a Samsung 
DSIM bridge")
Cc: sta...@vger.kernel.org
Signed-off-by: Osama Abdelkader <osama.abdelka...@gmail.com>
---
v2: 
- Move samsung_dsim_unregister_te_irq() function
- Add Fixes tag
- Add Cc tag
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c 
b/drivers/gpu/drm/bridge/samsung-dsim.c
index eabc4c32f6ab..ad8c6aa49d48 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1881,6 +1881,14 @@ static int samsung_dsim_register_te_irq(struct 
samsung_dsim *dsi, struct device
        return 0;
 }
 
+static void samsung_dsim_unregister_te_irq(struct samsung_dsim *dsi)
+{
+       if (dsi->te_gpio) {
+               free_irq(gpiod_to_irq(dsi->te_gpio), dsi);
+               gpiod_put(dsi->te_gpio);
+       }
+}
+
 static int samsung_dsim_host_attach(struct mipi_dsi_host *host,
                                    struct mipi_dsi_device *device)
 {
@@ -1955,13 +1963,13 @@ static int samsung_dsim_host_attach(struct 
mipi_dsi_host *host,
        if (!(device->mode_flags & MIPI_DSI_MODE_VIDEO)) {
                ret = samsung_dsim_register_te_irq(dsi, &device->dev);
                if (ret)
-                       return ret;
+                       goto err_remove_bridge;
        }
 
        if (pdata->host_ops && pdata->host_ops->attach) {
                ret = pdata->host_ops->attach(dsi, device);
                if (ret)
-                       return ret;
+                       goto err_unregister_te_irq;
        }
 
        dsi->lanes = device->lanes;
@@ -1969,14 +1977,13 @@ static int samsung_dsim_host_attach(struct 
mipi_dsi_host *host,
        dsi->mode_flags = device->mode_flags;
 
        return 0;
-}
 
-static void samsung_dsim_unregister_te_irq(struct samsung_dsim *dsi)
-{
-       if (dsi->te_gpio) {
-               free_irq(gpiod_to_irq(dsi->te_gpio), dsi);
-               gpiod_put(dsi->te_gpio);
-       }
+err_unregister_te_irq:
+       if (!(device->mode_flags & MIPI_DSI_MODE_VIDEO))
+               samsung_dsim_unregister_te_irq(dsi);
+err_remove_bridge:
+       drm_bridge_remove(&dsi->bridge);
+       return ret;
 }
 
 static int samsung_dsim_host_detach(struct mipi_dsi_host *host,
-- 
2.43.0