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: a3db10efcc ("net/smc: Add support for obtaining SMCR device list")
Reported-by: syzbot+600fef7c414ee7e2d71b@syzkaller.appspotmail.com
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20201215091058.49354-2-kgraul@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Karsten Graul 2020-12-15 10:10:58 +01:00 committed by Jakub Kicinski
parent ef72cd3c5c
commit 995433b795
1 changed files with 23 additions and 13 deletions

View File

@ -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;