Re: [PATCH net-next 01/18] net/smc: decouple ism_dev from SMC-D device dump

On 2023/9/22 04:41, Simon Horman wrote:

On Tue, Sep 19, 2023 at 10:41:45PM +0800, Wen Gu wrote:

quoted

This patch helps to decouple ISM device from SMC-D device, allowing
different underlying device forms, such as virtual ISM devices.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
  net/smc/smc_ism.c | 8 +++++---
  1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index fbee249..0045fee 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c

@@ -230,12 +230,11 @@ static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
  	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
  	struct smc_pci_dev smc_pci_dev;
  	struct nlattr *port_attrs;
+	struct device *priv_dev;
  	struct nlattr *attrs;
-	struct ism_dev *ism;
  	int use_cnt = 0;
  	void *nlh;
  
-	ism = smcd->priv;
  	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
  			  &smc_gen_nl_family, NLM_F_MULTI,
  			  SMC_NETLINK_GET_DEV_SMCD);

@@ -250,7 +249,10 @@ static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
  	if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, use_cnt > 0))
  		goto errattr;
  	memset(&smc_pci_dev, 0, sizeof(smc_pci_dev));

Hi Wen Gu,

priv_dev is uninitialised here.

quoted

-	smc_set_pci_values(to_pci_dev(ism->dev.parent), &smc_pci_dev);
+	if (smcd->ops->get_dev)
+		priv_dev = smcd->ops->get_dev(smcd);

It is conditionally initialised here.

quoted

+	if (priv_dev->parent)

But unconditionally dereferenced here.

As flagged by clang-16 W=1, and Smatch

Hi Simon. Yes, I fixed it in v3. Thank you!

quoted

+		smc_set_pci_values(to_pci_dev(priv_dev->parent), &smc_pci_dev);
  	if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev.pci_fid))
  		goto errattr;
  	if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev.pci_pchid))
-- 
1.8.3.1