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From:   Jianglei Nie <niejianglei2021@163.com>
To:     kvalo@kernel.org, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com
Cc:     ath11k@lists.infradead.org, linux-wireless@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jianglei Nie <niejianglei2021@163.com>
Subject: [PATCH] ath11k: mhi: fix potential memory leak in ath11k_mhi_register()
Date:   Wed,  7 Sep 2022 15:37:04 +0800
Message-Id: <20220907073704.58806-1-niejianglei2021@163.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

mhi_alloc_controller() allocates a memory space for mhi_ctrl. When gets
some error, mhi_ctrl should be freed with mhi_free_controller(). But
when ath11k_mhi_read_addr_from_dt() fails, the function returns without
calling mhi_free_controller(), which will lead to a memory leak.

We can fix it by calling mhi_free_controller() when
ath11k_mhi_read_addr_from_dt() fails.

Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
---
 drivers/net/wireless/ath/ath11k/mhi.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/mhi.c b/drivers/net/wireless/ath/ath11k/mhi.c
index c44df17719f6..86995e8dc913 100644
--- a/drivers/net/wireless/ath/ath11k/mhi.c
+++ b/drivers/net/wireless/ath/ath11k/mhi.c
@@ -402,8 +402,7 @@ int ath11k_mhi_register(struct ath11k_pci *ab_pci)
 	ret = ath11k_mhi_get_msi(ab_pci);
 	if (ret) {
 		ath11k_err(ab, "failed to get msi for mhi\n");
-		mhi_free_controller(mhi_ctrl);
-		return ret;
+		goto free_controller;
 	}
 
 	if (!test_bit(ATH11K_FLAG_MULTI_MSI_VECTORS, &ab->dev_flags))
@@ -412,7 +411,7 @@ int ath11k_mhi_register(struct ath11k_pci *ab_pci)
 	if (test_bit(ATH11K_FLAG_FIXED_MEM_RGN, &ab->dev_flags)) {
 		ret = ath11k_mhi_read_addr_from_dt(mhi_ctrl);
 		if (ret < 0)
-			return ret;
+			goto free_controller;
 	} else {
 		mhi_ctrl->iova_start = 0;
 		mhi_ctrl->iova_stop = 0xFFFFFFFF;
@@ -440,18 +439,22 @@ int ath11k_mhi_register(struct ath11k_pci *ab_pci)
 	default:
 		ath11k_err(ab, "failed assign mhi_config for unknown hw rev %d\n",
 			   ab->hw_rev);
-		mhi_free_controller(mhi_ctrl);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto free_controller;
 	}
 
 	ret = mhi_register_controller(mhi_ctrl, ath11k_mhi_config);
 	if (ret) {
 		ath11k_err(ab, "failed to register to mhi bus, err = %d\n", ret);
-		mhi_free_controller(mhi_ctrl);
-		return ret;
+		goto free_controller;
 	}
 
 	return 0;
+
+free_controller:
+	mhi_free_controller(mhi_ctrl);
+	ab_pci->mhi_ctrl = NULL;
+	return ret;
 }
 
 void ath11k_mhi_unregister(struct ath11k_pci *ab_pci)
-- 
2.25.1