From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jiasheng Jiang <jiasheng@iscas.ac.cn>,
        kernel test robot <lkp@intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 102/177] sfc_ef100: potential dereference of null pointer
Date:   Mon, 20 Dec 2021 15:34:12 +0100
Message-Id: <20211220143043.529990307@linuxfoundation.org>
In-Reply-To: <20211220143040.058287525@linuxfoundation.org>
References: <20211220143040.058287525@linuxfoundation.org>
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From: Jiasheng Jiang <jiasheng@iscas.ac.cn>

[ Upstream commit 407ecd1bd726f240123f704620d46e285ff30dd9 ]

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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 518268ce20644..d35cafd422b1c 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);
-- 
2.33.0