Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Alexander Duyck , Aaron Brown , Jeff Kirsher , Sasha Levin Subject: [PATCH 4.4 117/160] e1000: avoid null pointer dereference on invalid stat type Date: Mon, 19 Nov 2018 17:29:16 +0100 Message-Id: <20181119162642.043507561@linuxfoundation.org> In-Reply-To: <20181119162630.031306128@linuxfoundation.org> References: <20181119162630.031306128@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 5983587c8c5ef00d6886477544ad67d495bc5479 ] Currently if the stat type is invalid then data[i] is being set either by dereferencing a null pointer p, or it is reading from an incorrect previous location if we had a valid stat type previously. Fix this by skipping over the read of p on an invalid stat type. Detected by CoverityScan, CID#113385 ("Explicit null dereferenced") Signed-off-by: Colin Ian King Reviewed-by: Alexander Duyck Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/e1000/e1000_ethtool.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c index 5ae8874bbf72..d70b2e5d5222 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c +++ b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c @@ -1826,11 +1826,12 @@ static void e1000_get_ethtool_stats(struct net_device *netdev, { struct e1000_adapter *adapter = netdev_priv(netdev); int i; - char *p = NULL; const struct e1000_stats *stat = e1000_gstrings_stats; e1000_update_stats(adapter); - for (i = 0; i < E1000_GLOBAL_STATS_LEN; i++) { + for (i = 0; i < E1000_GLOBAL_STATS_LEN; i++, stat++) { + char *p; + switch (stat->type) { case NETDEV_STATS: p = (char *)netdev + stat->stat_offset; @@ -1841,15 +1842,13 @@ static void e1000_get_ethtool_stats(struct net_device *netdev, default: WARN_ONCE(1, "Invalid E1000 stat type: %u index %d\n", stat->type, i); - break; + continue; } if (stat->sizeof_stat == sizeof(u64)) data[i] = *(u64 *)p; else data[i] = *(u32 *)p; - - stat++; } /* BUG_ON(i != E1000_STATS_LEN); */ } -- 2.17.1