From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     ecree.xilinx@gmail.com, habetsm.xilinx@gmail.com,
        davem@davemloft.net, kuba@kernel.org
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jiasheng Jiang <jiasheng@iscas.ac.cn>,
        kernel test robot <lkp@intel.com>
Subject: [PATCH v2] sfc_ef100: potential dereference of null pointer
Date:   Wed, 15 Dec 2021 22:37:31 +0800
Message-Id: <20211215143731.188026-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The return value of kmalloc() needs to be checked.
To avoid use in efx_nic_update_stats() in case of the failure of alloc.

Fixes: b593b6f1b492 ("sfc_ef100: statistics gathering")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reported-by: kernel test robot <lkp@intel.com>
---
Changelog:

v1 -> v2

*Change 1. Change the place to check, avoiding the warning.
---
 drivers/net/ethernet/sfc/ef100_nic.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/sfc/ef100_nic.c b/drivers/net/ethernet/sfc/ef100_nic.c
index 518268ce2064..d35cafd422b1 100644
--- a/drivers/net/ethernet/sfc/ef100_nic.c
+++ b/drivers/net/ethernet/sfc/ef100_nic.c
@@ -609,6 +609,9 @@ static size_t ef100_update_stats(struct efx_nic *efx,
 	ef100_common_stat_mask(mask);
 	ef100_ethtool_stat_mask(mask);
 
+	if (!mc_stats)
+		return 0;
+
 	efx_nic_copy_stats(efx, mc_stats);
 	efx_nic_update_stats(ef100_stat_desc, EF100_STAT_COUNT, mask,
 			     stats, mc_stats, false);
-- 
2.25.1