[PATCH] AMD_SFH: Fix potential NULL pointer dereference

From: Evgeny Novikov <novikov@ispras.ru>
To: Nehal Shah <nehal-bakulchandra.shah@amd.com>
Cc: Evgeny Novikov <novikov@ispras.ru>,
	Sandeep Singh <sandeep.singh@amd.com>,
	Jiri Kosina <jikos@kernel.org>,
	Benjamin Tissoires <benjamin.tissoires@redhat.com>,
	linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
	ldv-project@linuxtesting.org
Subject: [PATCH] AMD_SFH: Fix potential NULL pointer dereference
Date: Tue,  1 Jun 2021 19:38:01 +0300	[thread overview]
Message-ID: <20210601163801.17848-1-novikov@ispras.ru> (raw)

devm_add_action_or_reset() can suddenly invoke amd_mp2_pci_remove() at
registration that will cause NULL pointer dereference since
corresponding data is not initialized yet. The patch moves
initialization of data before devm_add_action_or_reset().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
---
 drivers/hid/amd-sfh-hid/amd_sfh_pcie.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
index ddecc84fd6f0..8394565c4d01 100644
--- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
+++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
@@ -160,11 +160,16 @@ static int amd_mp2_pci_probe(struct pci_dev *pdev, const struct pci_device_id *i
 		rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
 		return rc;
 	}
+
+	rc = amd_sfh_hid_client_init(privdata);
+	if (rc)
+		return rc;
+
 	rc = devm_add_action_or_reset(&pdev->dev, amd_mp2_pci_remove, privdata);
 	if (rc)
 		return rc;
 
-	return amd_sfh_hid_client_init(privdata);
+	return 0;
 }
 
 static const struct pci_device_id amd_mp2_pci_tbl[] = {
-- 
2.26.2

