From 995433b795cec0a4ef6c8603e7642903c621943a Mon Sep 17 00:00:00 2001 From: Karsten Graul Date: Tue, 15 Dec 2020 10:10:58 +0100 Subject: [PATCH] net/smc: fix access to parent of an ib device The parent of an ib device is used to retrieve the PCI device attributes. It turns out that there are possible cases when an ib device has no parent set in the device structure, which may lead to page faults when trying to access this memory. Fix that by checking the parent pointer and consolidate the pci device specific processing in a new function. Fixes: a3db10efcc4c ("net/smc: Add support for obtaining SMCR device list") Reported-by: syzbot+600fef7c414ee7e2d71b@syzkaller.appspotmail.com Signed-off-by: Karsten Graul Link: https://lore.kernel.org/r/20201215091058.49354-2-kgraul@linux.ibm.com Signed-off-by: Jakub Kicinski --- net/smc/smc_ib.c | 36 +++++++++++++++++++++++------------- 1 file changed, 23 insertions(+), 13 deletions(-) diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c index 89ea10675a7d..ddd7fac98b1d 100644 --- a/net/smc/smc_ib.c +++ b/net/smc/smc_ib.c @@ -394,6 +394,22 @@ errout: return -EMSGSIZE; } +static bool smc_nl_handle_pci_values(const struct smc_pci_dev *smc_pci_dev, + struct sk_buff *skb) +{ + if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev->pci_fid)) + return false; + if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev->pci_pchid)) + return false; + if (nla_put_u16(skb, SMC_NLA_DEV_PCI_VENDOR, smc_pci_dev->pci_vendor)) + return false; + if (nla_put_u16(skb, SMC_NLA_DEV_PCI_DEVICE, smc_pci_dev->pci_device)) + return false; + if (nla_put_string(skb, SMC_NLA_DEV_PCI_ID, smc_pci_dev->pci_id)) + return false; + return true; +} + static int smc_nl_handle_smcr_dev(struct smc_ib_device *smcibdev, struct sk_buff *skb, struct netlink_callback *cb) @@ -417,19 +433,13 @@ static int smc_nl_handle_smcr_dev(struct smc_ib_device *smcibdev, is_crit = smcr_diag_is_dev_critical(&smc_lgr_list, smcibdev); if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, is_crit)) goto errattr; - memset(&smc_pci_dev, 0, sizeof(smc_pci_dev)); - pci_dev = to_pci_dev(smcibdev->ibdev->dev.parent); - smc_set_pci_values(pci_dev, &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)) - goto errattr; - if (nla_put_u16(skb, SMC_NLA_DEV_PCI_VENDOR, smc_pci_dev.pci_vendor)) - goto errattr; - if (nla_put_u16(skb, SMC_NLA_DEV_PCI_DEVICE, smc_pci_dev.pci_device)) - goto errattr; - if (nla_put_string(skb, SMC_NLA_DEV_PCI_ID, smc_pci_dev.pci_id)) - goto errattr; + if (smcibdev->ibdev->dev.parent) { + memset(&smc_pci_dev, 0, sizeof(smc_pci_dev)); + pci_dev = to_pci_dev(smcibdev->ibdev->dev.parent); + smc_set_pci_values(pci_dev, &smc_pci_dev); + if (!smc_nl_handle_pci_values(&smc_pci_dev, skb)) + goto errattr; + } snprintf(smc_ibname, sizeof(smc_ibname), "%s", smcibdev->ibdev->name); if (nla_put_string(skb, SMC_NLA_DEV_IB_NAME, smc_ibname)) goto errattr;