From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heinrich Schuchardt Subject: Re: [PATCH 1/1] net: thunderx: avoid null pointer dereference Date: Tue, 17 May 2016 23:37:11 +0200 Message-ID: <573B8F07.6080600@gmx.de> References: <1463514038-9008-1-git-send-email-xypron.glpk@gmx.de> <573B7D39.9050305@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: Sunil Goutham , Robert Richter , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org To: David Daney Return-path: In-Reply-To: <573B7D39.9050305@caviumnetworks.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 05/17/2016 10:21 PM, David Daney wrote: > On 05/17/2016 12:40 PM, Heinrich Schuchardt wrote: >> In function bgx_lmac_handler only use a member of >> lmac after checking it is not null. >> > > Were you seeing and actual OOPs, or is this only a theoretical problem > flagged by some sort of static code checker? Cppcheck identified the code inconsistency. If the struct netdev * parameter cannot be NULL, you could eliminate the check. Other drivers do no have check against a NULL parameter in the adjust_link handler function (e.g. bgmac_adjust_link, pxa168_eth_adjust_link). Best regards Heinrich > >> Signed-off-by: Heinrich Schuchardt > > In any event, it seems sane to make this change, so: > > Acked-by: David Daney > > >> --- >> drivers/net/ethernet/cavium/thunder/thunder_bgx.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c >> b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c >> index d20539a..3ed2198 100644 >> --- a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c >> +++ b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c >> @@ -274,12 +274,14 @@ static void bgx_sgmii_change_link_state(struct >> lmac *lmac) >> static void bgx_lmac_handler(struct net_device *netdev) >> { >> struct lmac *lmac = container_of(netdev, struct lmac, netdev); >> - struct phy_device *phydev = lmac->phydev; >> + struct phy_device *phydev; >> int link_changed = 0; >> >> if (!lmac) >> return; >> >> + phydev = lmac->phydev; >> + >> if (!phydev->link && lmac->last_link) >> link_changed = -1; >> >> > >