[PATCH] media: staging/ipu7: Fix pdata double free in init error paths

[Guangshuo Li <lgs201920130244@gmail.com>]

ipu7_bus_initialize_device() stores the caller allocated pdata pointer in
adev->pdata and installs ipu7_bus_release() as the device release callback.
After auxiliary_device_init() succeeds, pdata is released by
ipu7_bus_release().

The isys and psys init error paths still call kfree(pdata) after
put_device() or after ipu7_bus_add_device() fails. In both cases the
auxiliary device release callback has already been invoked, so pdata has
already been freed through adev->pdata.

Remove the duplicate kfree(pdata) calls. Also cache the MMU init error
before calling put_device(), since put_device() may release the auxiliary
device container.

This issue was found by a static analysis tool I am developing.

Fixes: b7fe4c0019b1 ("media: staging/ipu7: add Intel IPU7 PCI device driver")
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/staging/media/ipu7/ipu7.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/staging/media/ipu7/ipu7.c b/drivers/staging/media/ipu7/ipu7.c
index c771e763f8c5..069f0238c8cf 100644
--- a/drivers/staging/media/ipu7/ipu7.c
+++ b/drivers/staging/media/ipu7/ipu7.c
@@ -2169,21 +2169,19 @@ ipu7_isys_init(struct pci_dev *pdev, struct device *parent,
 	isys_adev->mmu = ipu7_mmu_init(dev, base, ISYS_MMID,
 				       &ipdata->hw_variant);
 	if (IS_ERR(isys_adev->mmu)) {
-		dev_err_probe(dev, PTR_ERR(isys_adev->mmu),
+		ret = PTR_ERR(isys_adev->mmu);
+		dev_err_probe(dev, ret,
 			      "ipu7_mmu_init(isys_adev->mmu) failed\n");
 		put_device(&isys_adev->auxdev.dev);
-		kfree(pdata);
-		return ERR_CAST(isys_adev->mmu);
+		return ERR_CAST(ret);
 	}
 
 	isys_adev->mmu->dev = &isys_adev->auxdev.dev;
 	isys_adev->subsys = IPU_IS;
 
 	ret = ipu7_bus_add_device(isys_adev);
-	if (ret) {
-		kfree(pdata);
+	if (ret)
 		return ERR_PTR(ret);
-	}
 
 	return isys_adev;
 }
@@ -2216,21 +2214,19 @@ ipu7_psys_init(struct pci_dev *pdev, struct device *parent,
 	psys_adev->mmu = ipu7_mmu_init(&pdev->dev, base, PSYS_MMID,
 				       &ipdata->hw_variant);
 	if (IS_ERR(psys_adev->mmu)) {
-		dev_err_probe(&pdev->dev, PTR_ERR(psys_adev->mmu),
+		ret = PTR_ERR(psys_adev->mmu);
+		dev_err_probe(&pdev->dev, ret,
 			      "ipu7_mmu_init(psys_adev->mmu) failed\n");
 		put_device(&psys_adev->auxdev.dev);
-		kfree(pdata);
-		return ERR_CAST(psys_adev->mmu);
+		return ERR_CAST(ret);
 	}
 
 	psys_adev->mmu->dev = &psys_adev->auxdev.dev;
 	psys_adev->subsys = IPU_PS;
 
 	ret = ipu7_bus_add_device(psys_adev);
-	if (ret) {
-		kfree(pdata);
+	if (ret)
 		return ERR_PTR(ret);
-	}
 
 	return psys_adev;
 }
-- 
2.43.0