| Message ID | 20180628135938.19625-1-nhorman@tuxdriver.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Thu, Jun 28, 2018 at 09:59:38AM -0400, Neil Horman wrote: > On repeated module load/unload cycles, its possible for the pvrmda > driver to encounter this crash: > > ... > 297.032448] RIP: 0010:[<ffffffff839e4620>] [<ffffffff839e4620>] netdev_walk_all_upper_dev_rcu+0x50/0xb0 > [ 297.034078] RSP: 0018:ffff95087780bd08 EFLAGS: 00010286 > [ 297.034986] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff95087a0c0000 > [ 297.036196] RDX: ffff95087a0c0000 RSI: ffffffff839e44e0 RDI: ffff950835d0c000 > [ 297.037421] RBP: ffff95087780bd40 R08: ffff95087a0e0ea0 R09: abddacd03f8e0ea0 > [ 297.038636] R10: abddacd03f8e0ea0 R11: ffffef5901e9dbc0 R12: ffff95087a0c0000 > [ 297.039854] R13: ffffffff839e44e0 R14: ffff95087a0c0000 R15: ffff950835d0c828 > [ 297.041071] FS: 0000000000000000(0000) GS:ffff95087fc00000(0000) knlGS:0000000000000000 > [ 297.042443] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 297.043429] CR2: ffffffffffffffe8 CR3: 000000007a652000 CR4: 00000000003607f0 > [ 297.044674] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 297.045893] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 297.047109] Call Trace: > [ 297.047545] [<ffffffff839e4698>] netdev_has_upper_dev_all_rcu+0x18/0x20 > [ 297.048691] [<ffffffffc05d31af>] is_eth_port_of_netdev+0x2f/0xa0 [ib_core] > [ 297.049886] [<ffffffffc05d3180>] ? is_eth_active_slave_of_bonding_rcu+0x70/0x70 [ib_core] > ... > > This occurs because vmw_pvrdma on probe stores a pointer to the netdev > that exists on function 0 of the same bus/device/slot (which represents > the vmxnet3 ethernet driver). However, it never removes this pointer if > the vmxnet3 module is removed, leading to crashes resulting from use > after free dereferencing incidents like the one above. > > The fix is pretty straightforward. vmw_pvrdma should listen for > NETDEV_REGISTER and NETDEV_UNREGISTER events in its event listener code > block, and update the stored netdev pointer accordingly. This solution > has been tested by myself and the reporter with successful results. > This fix also allows the pvrdma driver to find its underlying ethernet > device in the event that vmxnet3 is loaded after pvrdma, which it was > not able to do before. > > Signed-off-by: Neil Horman <nhorman@tuxdriver.com> > Reported-by: ruquin@redhat.com > CC: Adit Ranadive <aditr@vmware.com> > CC: VMware PV-Drivers <pv-drivers@vmware.com> > CC: Doug Ledford <dledford@redhat.com> > CC: Jason Gunthorpe <jgg@ziepe.ca> > CC: linux-kernel@vger.kernel.org > .../infiniband/hw/vmw_pvrdma/pvrdma_main.c | 25 +++++++++++++++++-- > 1 file changed, 23 insertions(+), 2 deletions(-) > > diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c > index 0be33a81bbe6..5b4782078a74 100644 > +++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c > @@ -699,8 +699,12 @@ static int pvrdma_del_gid(const struct ib_gid_attr *attr, void **context) > } > > static void pvrdma_netdevice_event_handle(struct pvrdma_dev *dev, > + struct net_device *ndev, > unsigned long event) > { > + struct pci_dev *pdev_net; > + > + > switch (event) { > case NETDEV_REBOOT: > case NETDEV_DOWN: > @@ -718,6 +722,21 @@ static void pvrdma_netdevice_event_handle(struct pvrdma_dev *dev, > else > pvrdma_dispatch_event(dev, 1, IB_EVENT_PORT_ACTIVE); > break; > + case NETDEV_UNREGISTER: > + dev_put(dev->netdev); > + dev->netdev = NULL; > + break; > + case NETDEV_REGISTER: > + /* Paired vmxnet3 will have same bus, slot. But func will be 0 */ > + pdev_net = pci_get_slot(dev->pdev->bus, PCI_DEVFN(PCI_SLOT(dev->pdev->devfn), 0)); > + if ((dev->netdev == NULL) && (pci_get_drvdata(pdev_net) == ndev)) { > + /* this is our netdev */ > + dev->netdev = ndev; > + dev_hold(ndev); > + } > + pci_dev_put(pdev_net); > + break; > + > default: > dev_dbg(&dev->pdev->dev, "ignore netdevice event %ld on %s\n", > event, dev->ib_dev.name); > @@ -734,8 +753,9 @@ static void pvrdma_netdevice_event_work(struct work_struct *work) > > mutex_lock(&pvrdma_device_list_lock); > list_for_each_entry(dev, &pvrdma_device_list, device_link) { > - if (dev->netdev == netdev_work->event_netdev) { > - pvrdma_netdevice_event_handle(dev, netdev_work->event); > + if ((netdev_work->event == NETDEV_REGISTER) || > + (dev->netdev == netdev_work->event_netdev)) { > + pvrdma_netdevice_event_handle(dev, netdev_work->event_netdev, netdev_work->event); > break; > } > } > @@ -962,6 +982,7 @@ static int pvrdma_pci_probe(struct pci_dev *pdev, > } > > dev->netdev = pci_get_drvdata(pdev_net); > + dev_hold(dev->netdev); > pci_dev_put(pdev_net); > if (!dev->netdev) { > dev_err(&pdev->dev, "failed to get vmxnet3 device\n"); I see a lot of new dev_hold's here, where are the matching dev_puts()? Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jun 28, 2018 at 12:59:46PM -0600, Jason Gunthorpe wrote: > On Thu, Jun 28, 2018 at 09:59:38AM -0400, Neil Horman wrote: > > On repeated module load/unload cycles, its possible for the pvrmda > > driver to encounter this crash: > > > > ... > > 297.032448] RIP: 0010:[<ffffffff839e4620>] [<ffffffff839e4620>] netdev_walk_all_upper_dev_rcu+0x50/0xb0 > > [ 297.034078] RSP: 0018:ffff95087780bd08 EFLAGS: 00010286 > > [ 297.034986] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff95087a0c0000 > > [ 297.036196] RDX: ffff95087a0c0000 RSI: ffffffff839e44e0 RDI: ffff950835d0c000 > > [ 297.037421] RBP: ffff95087780bd40 R08: ffff95087a0e0ea0 R09: abddacd03f8e0ea0 > > [ 297.038636] R10: abddacd03f8e0ea0 R11: ffffef5901e9dbc0 R12: ffff95087a0c0000 > > [ 297.039854] R13: ffffffff839e44e0 R14: ffff95087a0c0000 R15: ffff950835d0c828 > > [ 297.041071] FS: 0000000000000000(0000) GS:ffff95087fc00000(0000) knlGS:0000000000000000 > > [ 297.042443] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 297.043429] CR2: ffffffffffffffe8 CR3: 000000007a652000 CR4: 00000000003607f0 > > [ 297.044674] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > [ 297.045893] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > [ 297.047109] Call Trace: > > [ 297.047545] [<ffffffff839e4698>] netdev_has_upper_dev_all_rcu+0x18/0x20 > > [ 297.048691] [<ffffffffc05d31af>] is_eth_port_of_netdev+0x2f/0xa0 [ib_core] > > [ 297.049886] [<ffffffffc05d3180>] ? is_eth_active_slave_of_bonding_rcu+0x70/0x70 [ib_core] > > ... > > > > This occurs because vmw_pvrdma on probe stores a pointer to the netdev > > that exists on function 0 of the same bus/device/slot (which represents > > the vmxnet3 ethernet driver). However, it never removes this pointer if > > the vmxnet3 module is removed, leading to crashes resulting from use > > after free dereferencing incidents like the one above. > > > > The fix is pretty straightforward. vmw_pvrdma should listen for > > NETDEV_REGISTER and NETDEV_UNREGISTER events in its event listener code > > block, and update the stored netdev pointer accordingly. This solution > > has been tested by myself and the reporter with successful results. > > This fix also allows the pvrdma driver to find its underlying ethernet > > device in the event that vmxnet3 is loaded after pvrdma, which it was > > not able to do before. > > > > Signed-off-by: Neil Horman <nhorman@tuxdriver.com> > > Reported-by: ruquin@redhat.com > > CC: Adit Ranadive <aditr@vmware.com> > > CC: VMware PV-Drivers <pv-drivers@vmware.com> > > CC: Doug Ledford <dledford@redhat.com> > > CC: Jason Gunthorpe <jgg@ziepe.ca> > > CC: linux-kernel@vger.kernel.org > > .../infiniband/hw/vmw_pvrdma/pvrdma_main.c | 25 +++++++++++++++++-- > > 1 file changed, 23 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c > > index 0be33a81bbe6..5b4782078a74 100644 > > +++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c > > @@ -699,8 +699,12 @@ static int pvrdma_del_gid(const struct ib_gid_attr *attr, void **context) > > } > > > > static void pvrdma_netdevice_event_handle(struct pvrdma_dev *dev, > > + struct net_device *ndev, > > unsigned long event) > > { > > + struct pci_dev *pdev_net; > > + > > + > > switch (event) { > > case NETDEV_REBOOT: > > case NETDEV_DOWN: > > @@ -718,6 +722,21 @@ static void pvrdma_netdevice_event_handle(struct pvrdma_dev *dev, > > else > > pvrdma_dispatch_event(dev, 1, IB_EVENT_PORT_ACTIVE); > > break; > > + case NETDEV_UNREGISTER: > > + dev_put(dev->netdev); > > + dev->netdev = NULL; > > + break; > > + case NETDEV_REGISTER: > > + /* Paired vmxnet3 will have same bus, slot. But func will be 0 */ > > + pdev_net = pci_get_slot(dev->pdev->bus, PCI_DEVFN(PCI_SLOT(dev->pdev->devfn), 0)); > > + if ((dev->netdev == NULL) && (pci_get_drvdata(pdev_net) == ndev)) { > > + /* this is our netdev */ > > + dev->netdev = ndev; > > + dev_hold(ndev); > > + } > > + pci_dev_put(pdev_net); > > + break; > > + > > default: > > dev_dbg(&dev->pdev->dev, "ignore netdevice event %ld on %s\n", > > event, dev->ib_dev.name); > > @@ -734,8 +753,9 @@ static void pvrdma_netdevice_event_work(struct work_struct *work) > > > > mutex_lock(&pvrdma_device_list_lock); > > list_for_each_entry(dev, &pvrdma_device_list, device_link) { > > - if (dev->netdev == netdev_work->event_netdev) { > > - pvrdma_netdevice_event_handle(dev, netdev_work->event); > > + if ((netdev_work->event == NETDEV_REGISTER) || > > + (dev->netdev == netdev_work->event_netdev)) { > > + pvrdma_netdevice_event_handle(dev, netdev_work->event_netdev, netdev_work->event); > > break; > > } > > } > > @@ -962,6 +982,7 @@ static int pvrdma_pci_probe(struct pci_dev *pdev, > > } > > > > dev->netdev = pci_get_drvdata(pdev_net); > > + dev_hold(dev->netdev); > > pci_dev_put(pdev_net); > > if (!dev->netdev) { > > dev_err(&pdev->dev, "failed to get vmxnet3 device\n"); > > I see a lot of new dev_hold's here, where are the matching > dev_puts()? > I'm not sure I'd call 2 alot, but sure, there is a new dev_hold in the pvrdma_pci_probe routine, to hold a reference to the netdev that is looked up there. It is balanced by the NETDEV_UNREGISTER case in pvrdma_netdevice_event_handle. The UNREGISTER clause is also balancing the NETDEV_REGISTER case of the hanlder that looks up the matching netdev should a new device be registered. Note that we will only hold a single device at a time, because a given pvrdma device only recongnizes a single vmxnet3 device (the one on function 0 of its own bus/device tuple). Note also that, under normal circumstances, the dev_hold/dev_put pair isn't needed, but in this case it is, because pvrdma for some reason defers net event notifications to a work queue that executes after the notifier chain completes. Neil > Jason > -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jun 28, 2018 at 03:45:26PM -0400, Neil Horman wrote: > On Thu, Jun 28, 2018 at 12:59:46PM -0600, Jason Gunthorpe wrote: > > On Thu, Jun 28, 2018 at 09:59:38AM -0400, Neil Horman wrote: > > > On repeated module load/unload cycles, its possible for the pvrmda > > > driver to encounter this crash: > > > > > > ... > > > 297.032448] RIP: 0010:[<ffffffff839e4620>] [<ffffffff839e4620>] netdev_walk_all_upper_dev_rcu+0x50/0xb0 > > > [ 297.034078] RSP: 0018:ffff95087780bd08 EFLAGS: 00010286 > > > [ 297.034986] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff95087a0c0000 > > > [ 297.036196] RDX: ffff95087a0c0000 RSI: ffffffff839e44e0 RDI: ffff950835d0c000 > > > [ 297.037421] RBP: ffff95087780bd40 R08: ffff95087a0e0ea0 R09: abddacd03f8e0ea0 > > > [ 297.038636] R10: abddacd03f8e0ea0 R11: ffffef5901e9dbc0 R12: ffff95087a0c0000 > > > [ 297.039854] R13: ffffffff839e44e0 R14: ffff95087a0c0000 R15: ffff950835d0c828 > > > [ 297.041071] FS: 0000000000000000(0000) GS:ffff95087fc00000(0000) knlGS:0000000000000000 > > > [ 297.042443] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > [ 297.043429] CR2: ffffffffffffffe8 CR3: 000000007a652000 CR4: 00000000003607f0 > > > [ 297.044674] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > > [ 297.045893] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > [ 297.047109] Call Trace: > > > [ 297.047545] [<ffffffff839e4698>] netdev_has_upper_dev_all_rcu+0x18/0x20 > > > [ 297.048691] [<ffffffffc05d31af>] is_eth_port_of_netdev+0x2f/0xa0 [ib_core] > > > [ 297.049886] [<ffffffffc05d3180>] ? is_eth_active_slave_of_bonding_rcu+0x70/0x70 [ib_core] > > > ... > > > > > > This occurs because vmw_pvrdma on probe stores a pointer to the netdev > > > that exists on function 0 of the same bus/device/slot (which represents > > > the vmxnet3 ethernet driver). However, it never removes this pointer if > > > the vmxnet3 module is removed, leading to crashes resulting from use > > > after free dereferencing incidents like the one above. > > > > > > The fix is pretty straightforward. vmw_pvrdma should listen for > > > NETDEV_REGISTER and NETDEV_UNREGISTER events in its event listener code > > > block, and update the stored netdev pointer accordingly. This solution > > > has been tested by myself and the reporter with successful results. > > > This fix also allows the pvrdma driver to find its underlying ethernet > > > device in the event that vmxnet3 is loaded after pvrdma, which it was > > > not able to do before. > > > > > > Signed-off-by: Neil Horman <nhorman@tuxdriver.com> > > > Reported-by: ruquin@redhat.com > > > CC: Adit Ranadive <aditr@vmware.com> > > > CC: VMware PV-Drivers <pv-drivers@vmware.com> > > > CC: Doug Ledford <dledford@redhat.com> > > > CC: Jason Gunthorpe <jgg@ziepe.ca> > > > CC: linux-kernel@vger.kernel.org > > > .../infiniband/hw/vmw_pvrdma/pvrdma_main.c | 25 +++++++++++++++++-- > > > 1 file changed, 23 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c > > > index 0be33a81bbe6..5b4782078a74 100644 > > > +++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c > > > @@ -699,8 +699,12 @@ static int pvrdma_del_gid(const struct ib_gid_attr *attr, void **context) > > > } > > > > > > static void pvrdma_netdevice_event_handle(struct pvrdma_dev *dev, > > > + struct net_device *ndev, > > > unsigned long event) > > > { > > > + struct pci_dev *pdev_net; > > > + > > > + > > > switch (event) { > > > case NETDEV_REBOOT: > > > case NETDEV_DOWN: > > > @@ -718,6 +722,21 @@ static void pvrdma_netdevice_event_handle(struct pvrdma_dev *dev, > > > else > > > pvrdma_dispatch_event(dev, 1, IB_EVENT_PORT_ACTIVE); > > > break; > > > + case NETDEV_UNREGISTER: > > > + dev_put(dev->netdev); > > > + dev->netdev = NULL; > > > + break; > > > + case NETDEV_REGISTER: > > > + /* Paired vmxnet3 will have same bus, slot. But func will be 0 */ > > > + pdev_net = pci_get_slot(dev->pdev->bus, PCI_DEVFN(PCI_SLOT(dev->pdev->devfn), 0)); > > > + if ((dev->netdev == NULL) && (pci_get_drvdata(pdev_net) == ndev)) { > > > + /* this is our netdev */ > > > + dev->netdev = ndev; > > > + dev_hold(ndev); > > > + } > > > + pci_dev_put(pdev_net); > > > + break; > > > + > > > default: > > > dev_dbg(&dev->pdev->dev, "ignore netdevice event %ld on %s\n", > > > event, dev->ib_dev.name); > > > @@ -734,8 +753,9 @@ static void pvrdma_netdevice_event_work(struct work_struct *work) > > > > > > mutex_lock(&pvrdma_device_list_lock); > > > list_for_each_entry(dev, &pvrdma_device_list, device_link) { > > > - if (dev->netdev == netdev_work->event_netdev) { > > > - pvrdma_netdevice_event_handle(dev, netdev_work->event); > > > + if ((netdev_work->event == NETDEV_REGISTER) || > > > + (dev->netdev == netdev_work->event_netdev)) { > > > + pvrdma_netdevice_event_handle(dev, netdev_work->event_netdev, netdev_work->event); > > > break; > > > } > > > } > > > @@ -962,6 +982,7 @@ static int pvrdma_pci_probe(struct pci_dev *pdev, > > > } > > > > > > dev->netdev = pci_get_drvdata(pdev_net); > > > + dev_hold(dev->netdev); > > > pci_dev_put(pdev_net); > > > if (!dev->netdev) { > > > dev_err(&pdev->dev, "failed to get vmxnet3 device\n"); > > > > I see a lot of new dev_hold's here, where are the matching > > dev_puts()? > > > I'm not sure I'd call 2 alot, but sure, there is a new dev_hold in the > pvrdma_pci_probe routine, to hold a reference to the netdev that is looked up > there. It is balanced by the NETDEV_UNREGISTER case in > pvrdma_netdevice_event_handle. The UNREGISTER clause is also balancing the > NETDEV_REGISTER case of the hanlder that looks up the matching netdev should a > new device be registered. Note that we will only hold a single device at a > time, because a given pvrdma device only recongnizes a single vmxnet3 device > (the one on function 0 of its own bus/device tuple). I don't see how the dev_hold in pvrdma_pci_probe is undone during error unwind (eg goto err_free_cq_ring) And I don't see how it is put when pvrdma_pci_remove() is called. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
T24gNi8yOC8xOCwgMTozNyBQTSwgIkphc29uIEd1bnRob3JwZSIgPGpnZ0B6aWVwZS5jYT4gd3Jv dGU6DQo+IE9uIFRodSwgSnVuIDI4LCAyMDE4IGF0IDAzOjQ1OjI2UE0gLTA0MDAsIE5laWwgSG9y bWFuIHdyb3RlOg0KPiA+IE9uIFRodSwgSnVuIDI4LCAyMDE4IGF0IDEyOjU5OjQ2UE0gLTA2MDAs IEphc29uIEd1bnRob3JwZSB3cm90ZToNCj4gPiA+IE9uIFRodSwgSnVuIDI4LCAyMDE4IGF0IDA5 OjU5OjM4QU0gLTA0MDAsIE5laWwgSG9ybWFuIHdyb3RlOg0KPiA+ID4gPiBPbiByZXBlYXRlZCBt b2R1bGUgbG9hZC91bmxvYWQgY3ljbGVzLCBpdHMgcG9zc2libGUgZm9yIHRoZSBwdnJtZGENCj4g PiA+ID4gZHJpdmVyIHRvIGVuY291bnRlciB0aGlzIGNyYXNoOg0KPHNuaXA+DQo+ID4gPiA+IEBA IC05NjIsNiArOTgyLDcgQEAgc3RhdGljIGludCBwdnJkbWFfcGNpX3Byb2JlKHN0cnVjdCBwY2lf ZGV2ICpwZGV2LA0KPiA+ID4gPiAgCX0NCj4gPiA+ID4gIA0KPiA+ID4gPiAgCWRldi0+bmV0ZGV2 ID0gcGNpX2dldF9kcnZkYXRhKHBkZXZfbmV0KTsNCj4gPiA+ID4gKwlkZXZfaG9sZChkZXYtPm5l dGRldik7DQoNClRoYXQgZG9lc24ndCBzZWVtIHJpZ2h0LiBJZiB0aGUgdm14bmV0MyBkcml2ZXIg aXNuJ3QgbG9hZGVkIGF0IGFsbCBvciBmYWlsZWQNCnRvIGNyZWF0ZSBhIG5ldGRldiwgeW91IHdv dWxkIGJlIHJlcXVlc3RpbmcgYSBob2xkIG9uIGEgTlVMTCBuZXRkZXYuIFdoYXQgaWYNCnlvdSBt b3ZlZCB0aGlzIHRvIGFmdGVyIHRoZSBpZighZGV2LT5uZXRkZXYpIGNoZWNrPw0KDQo+ID4gPiA+ ICAJcGNpX2Rldl9wdXQocGRldl9uZXQpOw0KPiA+ID4gPiAgCWlmICghZGV2LT5uZXRkZXYpIHsN Cj4gPiA+ID4gIAkJZGV2X2VycigmcGRldi0+ZGV2LCAiZmFpbGVkIHRvIGdldCB2bXhuZXQzIGRl dmljZVxuIik7DQo+ID4gPiANCj4gPiA+IEkgc2VlIGEgbG90IG9mIG5ldyBkZXZfaG9sZCdzIGhl cmUsIHdoZXJlIGFyZSB0aGUgbWF0Y2hpbmcNCj4gPiA+IGRldl9wdXRzKCk/DQo+ID4gPiANCj4g SSdtIG5vdCBzdXJlIEknZCBjYWxsIDIgYWxvdCwgYnV0IHN1cmUsIHRoZXJlIGlzIGEgbmV3IGRl dl9ob2xkIGluIHRoZQ0KPiBwdnJkbWFfcGNpX3Byb2JlIHJvdXRpbmUsIHRvIGhvbGQgYSByZWZl cmVuY2UgdG8gdGhlIG5ldGRldiB0aGF0IGlzIGxvb2tlZCB1cA0KPiB0aGVyZS4gIEl0IGlzIGJh bGFuY2VkIGJ5IHRoZSBORVRERVZfVU5SRUdJU1RFUiBjYXNlIGluDQo+IHB2cmRtYV9uZXRkZXZp Y2VfZXZlbnRfaGFuZGxlLiAgVGhlIFVOUkVHSVNURVIgY2xhdXNlIGlzIGFsc28gYmFsYW5jaW5n IHRoZQ0KPiBORVRERVZfUkVHSVNURVIgY2FzZSBvZiB0aGUgaGFubGRlciB0aGF0IGxvb2tzIHVw IHRoZSBtYXRjaGluZyBuZXRkZXYgc2hvdWxkIGENCj4gbmV3IGRldmljZSBiZSByZWdpc3RlcmVk LiAgTm90ZSB0aGF0IHdlIHdpbGwgb25seSBob2xkIGEgc2luZ2xlIGRldmljZSBhdCBhDQo+IHRp bWUsIGJlY2F1c2UgYSBnaXZlbiBwdnJkbWEgZGV2aWNlIG9ubHkgcmVjb25nbml6ZXMgYSBzaW5n bGUgdm14bmV0MyBkZXZpY2UNCj4gKHRoZSBvbmUgb24gZnVuY3Rpb24gMCBvZiBpdHMgb3duIGJ1 cy9kZXZpY2UgdHVwbGUpLg0KPiANCj4gSSBkb24ndCBzZWUgaG93IHRoZSBkZXZfaG9sZCBpbiBw dnJkbWFfcGNpX3Byb2JlIGlzIHVuZG9uZSBkdXJpbmcNCj4gZXJyb3IgdW53aW5kIChlZyBnb3Rv IGVycl9mcmVlX2NxX3JpbmcpDQo+IA0KPiBBbmQgSSBkb24ndCBzZWUgaG93IGl0IGlzIHB1dCB3 aGVuIHB2cmRtYV9wY2lfcmVtb3ZlKCkgaXMgY2FsbGVkLg0KDQpUaGF0J3MgcmlnaHQuIFRoZXNl IHNlZW0gbWlzc2luZyBhcyB3ZWxsLiANCg0K -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jun 28, 2018 at 02:37:09PM -0600, Jason Gunthorpe wrote: > On Thu, Jun 28, 2018 at 03:45:26PM -0400, Neil Horman wrote: > > On Thu, Jun 28, 2018 at 12:59:46PM -0600, Jason Gunthorpe wrote: > > > On Thu, Jun 28, 2018 at 09:59:38AM -0400, Neil Horman wrote: > > > > On repeated module load/unload cycles, its possible for the pvrmda > > > > driver to encounter this crash: > > > > > > > > ... > > > > 297.032448] RIP: 0010:[<ffffffff839e4620>] [<ffffffff839e4620>] netdev_walk_all_upper_dev_rcu+0x50/0xb0 > > > > [ 297.034078] RSP: 0018:ffff95087780bd08 EFLAGS: 00010286 > > > > [ 297.034986] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff95087a0c0000 > > > > [ 297.036196] RDX: ffff95087a0c0000 RSI: ffffffff839e44e0 RDI: ffff950835d0c000 > > > > [ 297.037421] RBP: ffff95087780bd40 R08: ffff95087a0e0ea0 R09: abddacd03f8e0ea0 > > > > [ 297.038636] R10: abddacd03f8e0ea0 R11: ffffef5901e9dbc0 R12: ffff95087a0c0000 > > > > [ 297.039854] R13: ffffffff839e44e0 R14: ffff95087a0c0000 R15: ffff950835d0c828 > > > > [ 297.041071] FS: 0000000000000000(0000) GS:ffff95087fc00000(0000) knlGS:0000000000000000 > > > > [ 297.042443] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > [ 297.043429] CR2: ffffffffffffffe8 CR3: 000000007a652000 CR4: 00000000003607f0 > > > > [ 297.044674] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > > > [ 297.045893] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > > [ 297.047109] Call Trace: > > > > [ 297.047545] [<ffffffff839e4698>] netdev_has_upper_dev_all_rcu+0x18/0x20 > > > > [ 297.048691] [<ffffffffc05d31af>] is_eth_port_of_netdev+0x2f/0xa0 [ib_core] > > > > [ 297.049886] [<ffffffffc05d3180>] ? is_eth_active_slave_of_bonding_rcu+0x70/0x70 [ib_core] > > > > ... > > > > > > > > This occurs because vmw_pvrdma on probe stores a pointer to the netdev > > > > that exists on function 0 of the same bus/device/slot (which represents > > > > the vmxnet3 ethernet driver). However, it never removes this pointer if > > > > the vmxnet3 module is removed, leading to crashes resulting from use > > > > after free dereferencing incidents like the one above. > > > > > > > > The fix is pretty straightforward. vmw_pvrdma should listen for > > > > NETDEV_REGISTER and NETDEV_UNREGISTER events in its event listener code > > > > block, and update the stored netdev pointer accordingly. This solution > > > > has been tested by myself and the reporter with successful results. > > > > This fix also allows the pvrdma driver to find its underlying ethernet > > > > device in the event that vmxnet3 is loaded after pvrdma, which it was > > > > not able to do before. > > > > > > > > Signed-off-by: Neil Horman <nhorman@tuxdriver.com> > > > > Reported-by: ruquin@redhat.com > > > > CC: Adit Ranadive <aditr@vmware.com> > > > > CC: VMware PV-Drivers <pv-drivers@vmware.com> > > > > CC: Doug Ledford <dledford@redhat.com> > > > > CC: Jason Gunthorpe <jgg@ziepe.ca> > > > > CC: linux-kernel@vger.kernel.org > > > > .../infiniband/hw/vmw_pvrdma/pvrdma_main.c | 25 +++++++++++++++++-- > > > > 1 file changed, 23 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c > > > > index 0be33a81bbe6..5b4782078a74 100644 > > > > +++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c > > > > @@ -699,8 +699,12 @@ static int pvrdma_del_gid(const struct ib_gid_attr *attr, void **context) > > > > } > > > > > > > > static void pvrdma_netdevice_event_handle(struct pvrdma_dev *dev, > > > > + struct net_device *ndev, > > > > unsigned long event) > > > > { > > > > + struct pci_dev *pdev_net; > > > > + > > > > + > > > > switch (event) { > > > > case NETDEV_REBOOT: > > > > case NETDEV_DOWN: > > > > @@ -718,6 +722,21 @@ static void pvrdma_netdevice_event_handle(struct pvrdma_dev *dev, > > > > else > > > > pvrdma_dispatch_event(dev, 1, IB_EVENT_PORT_ACTIVE); > > > > break; > > > > + case NETDEV_UNREGISTER: > > > > + dev_put(dev->netdev); > > > > + dev->netdev = NULL; > > > > + break; > > > > + case NETDEV_REGISTER: > > > > + /* Paired vmxnet3 will have same bus, slot. But func will be 0 */ > > > > + pdev_net = pci_get_slot(dev->pdev->bus, PCI_DEVFN(PCI_SLOT(dev->pdev->devfn), 0)); > > > > + if ((dev->netdev == NULL) && (pci_get_drvdata(pdev_net) == ndev)) { > > > > + /* this is our netdev */ > > > > + dev->netdev = ndev; > > > > + dev_hold(ndev); > > > > + } > > > > + pci_dev_put(pdev_net); > > > > + break; > > > > + > > > > default: > > > > dev_dbg(&dev->pdev->dev, "ignore netdevice event %ld on %s\n", > > > > event, dev->ib_dev.name); > > > > @@ -734,8 +753,9 @@ static void pvrdma_netdevice_event_work(struct work_struct *work) > > > > > > > > mutex_lock(&pvrdma_device_list_lock); > > > > list_for_each_entry(dev, &pvrdma_device_list, device_link) { > > > > - if (dev->netdev == netdev_work->event_netdev) { > > > > - pvrdma_netdevice_event_handle(dev, netdev_work->event); > > > > + if ((netdev_work->event == NETDEV_REGISTER) || > > > > + (dev->netdev == netdev_work->event_netdev)) { > > > > + pvrdma_netdevice_event_handle(dev, netdev_work->event_netdev, netdev_work->event); > > > > break; > > > > } > > > > } > > > > @@ -962,6 +982,7 @@ static int pvrdma_pci_probe(struct pci_dev *pdev, > > > > } > > > > > > > > dev->netdev = pci_get_drvdata(pdev_net); > > > > + dev_hold(dev->netdev); > > > > pci_dev_put(pdev_net); > > > > if (!dev->netdev) { > > > > dev_err(&pdev->dev, "failed to get vmxnet3 device\n"); > > > > > > I see a lot of new dev_hold's here, where are the matching > > > dev_puts()? > > > > > I'm not sure I'd call 2 alot, but sure, there is a new dev_hold in the > > pvrdma_pci_probe routine, to hold a reference to the netdev that is looked up > > there. It is balanced by the NETDEV_UNREGISTER case in > > pvrdma_netdevice_event_handle. The UNREGISTER clause is also balancing the > > NETDEV_REGISTER case of the hanlder that looks up the matching netdev should a > > new device be registered. Note that we will only hold a single device at a > > time, because a given pvrdma device only recongnizes a single vmxnet3 device > > (the one on function 0 of its own bus/device tuple). > > I don't see how the dev_hold in pvrdma_pci_probe is undone during > error unwind (eg goto err_free_cq_ring) > Ah, I missed that, thank you, I'll update the patch. > And I don't see how it is put when pvrdma_pci_remove() is called. > Yup, you're right, it should be dropped there too, immediately after the unregisteration of the netdevice notifier. > Jason > -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jun 28, 2018 at 09:15:46PM +0000, Adit Ranadive wrote: > On 6/28/18, 1:37 PM, "Jason Gunthorpe" <jgg@ziepe.ca> wrote: > > On Thu, Jun 28, 2018 at 03:45:26PM -0400, Neil Horman wrote: > > > On Thu, Jun 28, 2018 at 12:59:46PM -0600, Jason Gunthorpe wrote: > > > > On Thu, Jun 28, 2018 at 09:59:38AM -0400, Neil Horman wrote: > > > > > On repeated module load/unload cycles, its possible for the pvrmda > > > > > driver to encounter this crash: > <snip> > > > > > @@ -962,6 +982,7 @@ static int pvrdma_pci_probe(struct pci_dev *pdev, > > > > > } > > > > > > > > > > dev->netdev = pci_get_drvdata(pdev_net); > > > > > + dev_hold(dev->netdev); > > That doesn't seem right. If the vmxnet3 driver isn't loaded at all or failed > to create a netdev, you would be requesting a hold on a NULL netdev. What if > you moved this to after the if(!dev->netdev) check? > You're correct, I was thinking that there was a null check in dev_hold, but there isn't, it needs to be moved after the the !dev->netdev, and released in the error path. > > > > > pci_dev_put(pdev_net); > > > > > if (!dev->netdev) { > > > > > dev_err(&pdev->dev, "failed to get vmxnet3 device\n"); > > > > > > > > I see a lot of new dev_hold's here, where are the matching > > > > dev_puts()? > > > > > > I'm not sure I'd call 2 alot, but sure, there is a new dev_hold in the > > pvrdma_pci_probe routine, to hold a reference to the netdev that is looked up > > there. It is balanced by the NETDEV_UNREGISTER case in > > pvrdma_netdevice_event_handle. The UNREGISTER clause is also balancing the > > NETDEV_REGISTER case of the hanlder that looks up the matching netdev should a > > new device be registered. Note that we will only hold a single device at a > > time, because a given pvrdma device only recongnizes a single vmxnet3 device > > (the one on function 0 of its own bus/device tuple). > > > > I don't see how the dev_hold in pvrdma_pci_probe is undone during > > error unwind (eg goto err_free_cq_ring) > > > > And I don't see how it is put when pvrdma_pci_remove() is called. > > That's right. These seem missing as well. > yup -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Neil,
I love your patch! Perhaps something to improve:
url: https://github.com/0day-ci/linux/commits/Neil-Horman/vmw_pvrdma-Release-netdev-when-vmxnet3-module-is-removed/20180628-232414
smatch warnings:
drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c:987 pvrdma_pci_probe() warn: variable dereferenced before check 'dev->netdev' (see line 985)
# https://github.com/0day-ci/linux/commit/d5bb424e18e2ecab4ac590a66b0cca9dfb96d3da
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout d5bb424e18e2ecab4ac590a66b0cca9dfb96d3da
vim +987 drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c
29c8d9eb Adit Ranadive 2016-10-02 784
29c8d9eb Adit Ranadive 2016-10-02 785 static int pvrdma_pci_probe(struct pci_dev *pdev,
29c8d9eb Adit Ranadive 2016-10-02 786 const struct pci_device_id *id)
29c8d9eb Adit Ranadive 2016-10-02 787 {
29c8d9eb Adit Ranadive 2016-10-02 788 struct pci_dev *pdev_net;
29c8d9eb Adit Ranadive 2016-10-02 789 struct pvrdma_dev *dev;
29c8d9eb Adit Ranadive 2016-10-02 790 int ret;
29c8d9eb Adit Ranadive 2016-10-02 791 unsigned long start;
29c8d9eb Adit Ranadive 2016-10-02 792 unsigned long len;
29c8d9eb Adit Ranadive 2016-10-02 793 dma_addr_t slot_dma = 0;
29c8d9eb Adit Ranadive 2016-10-02 794
29c8d9eb Adit Ranadive 2016-10-02 795 dev_dbg(&pdev->dev, "initializing driver %s\n", pci_name(pdev));
29c8d9eb Adit Ranadive 2016-10-02 796
29c8d9eb Adit Ranadive 2016-10-02 797 /* Allocate zero-out device */
29c8d9eb Adit Ranadive 2016-10-02 798 dev = (struct pvrdma_dev *)ib_alloc_device(sizeof(*dev));
29c8d9eb Adit Ranadive 2016-10-02 799 if (!dev) {
29c8d9eb Adit Ranadive 2016-10-02 800 dev_err(&pdev->dev, "failed to allocate IB device\n");
29c8d9eb Adit Ranadive 2016-10-02 801 return -ENOMEM;
29c8d9eb Adit Ranadive 2016-10-02 802 }
29c8d9eb Adit Ranadive 2016-10-02 803
29c8d9eb Adit Ranadive 2016-10-02 804 mutex_lock(&pvrdma_device_list_lock);
29c8d9eb Adit Ranadive 2016-10-02 805 list_add(&dev->device_link, &pvrdma_device_list);
29c8d9eb Adit Ranadive 2016-10-02 806 mutex_unlock(&pvrdma_device_list_lock);
29c8d9eb Adit Ranadive 2016-10-02 807
29c8d9eb Adit Ranadive 2016-10-02 808 ret = pvrdma_init_device(dev);
29c8d9eb Adit Ranadive 2016-10-02 809 if (ret)
29c8d9eb Adit Ranadive 2016-10-02 810 goto err_free_device;
29c8d9eb Adit Ranadive 2016-10-02 811
29c8d9eb Adit Ranadive 2016-10-02 812 dev->pdev = pdev;
29c8d9eb Adit Ranadive 2016-10-02 813 pci_set_drvdata(pdev, dev);
29c8d9eb Adit Ranadive 2016-10-02 814
29c8d9eb Adit Ranadive 2016-10-02 815 ret = pci_enable_device(pdev);
29c8d9eb Adit Ranadive 2016-10-02 816 if (ret) {
29c8d9eb Adit Ranadive 2016-10-02 817 dev_err(&pdev->dev, "cannot enable PCI device\n");
29c8d9eb Adit Ranadive 2016-10-02 818 goto err_free_device;
29c8d9eb Adit Ranadive 2016-10-02 819 }
29c8d9eb Adit Ranadive 2016-10-02 820
29c8d9eb Adit Ranadive 2016-10-02 821 dev_dbg(&pdev->dev, "PCI resource flags BAR0 %#lx\n",
29c8d9eb Adit Ranadive 2016-10-02 822 pci_resource_flags(pdev, 0));
29c8d9eb Adit Ranadive 2016-10-02 823 dev_dbg(&pdev->dev, "PCI resource len %#llx\n",
29c8d9eb Adit Ranadive 2016-10-02 824 (unsigned long long)pci_resource_len(pdev, 0));
29c8d9eb Adit Ranadive 2016-10-02 825 dev_dbg(&pdev->dev, "PCI resource start %#llx\n",
29c8d9eb Adit Ranadive 2016-10-02 826 (unsigned long long)pci_resource_start(pdev, 0));
29c8d9eb Adit Ranadive 2016-10-02 827 dev_dbg(&pdev->dev, "PCI resource flags BAR1 %#lx\n",
29c8d9eb Adit Ranadive 2016-10-02 828 pci_resource_flags(pdev, 1));
29c8d9eb Adit Ranadive 2016-10-02 829 dev_dbg(&pdev->dev, "PCI resource len %#llx\n",
29c8d9eb Adit Ranadive 2016-10-02 830 (unsigned long long)pci_resource_len(pdev, 1));
29c8d9eb Adit Ranadive 2016-10-02 831 dev_dbg(&pdev->dev, "PCI resource start %#llx\n",
29c8d9eb Adit Ranadive 2016-10-02 832 (unsigned long long)pci_resource_start(pdev, 1));
29c8d9eb Adit Ranadive 2016-10-02 833
29c8d9eb Adit Ranadive 2016-10-02 834 if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
29c8d9eb Adit Ranadive 2016-10-02 835 !(pci_resource_flags(pdev, 1) & IORESOURCE_MEM)) {
29c8d9eb Adit Ranadive 2016-10-02 836 dev_err(&pdev->dev, "PCI BAR region not MMIO\n");
29c8d9eb Adit Ranadive 2016-10-02 837 ret = -ENOMEM;
29c8d9eb Adit Ranadive 2016-10-02 838 goto err_free_device;
29c8d9eb Adit Ranadive 2016-10-02 839 }
29c8d9eb Adit Ranadive 2016-10-02 840
29c8d9eb Adit Ranadive 2016-10-02 841 ret = pci_request_regions(pdev, DRV_NAME);
29c8d9eb Adit Ranadive 2016-10-02 842 if (ret) {
29c8d9eb Adit Ranadive 2016-10-02 843 dev_err(&pdev->dev, "cannot request PCI resources\n");
29c8d9eb Adit Ranadive 2016-10-02 844 goto err_disable_pdev;
29c8d9eb Adit Ranadive 2016-10-02 845 }
29c8d9eb Adit Ranadive 2016-10-02 846
29c8d9eb Adit Ranadive 2016-10-02 847 /* Enable 64-Bit DMA */
29c8d9eb Adit Ranadive 2016-10-02 848 if (pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) == 0) {
29c8d9eb Adit Ranadive 2016-10-02 849 ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
29c8d9eb Adit Ranadive 2016-10-02 850 if (ret != 0) {
29c8d9eb Adit Ranadive 2016-10-02 851 dev_err(&pdev->dev,
29c8d9eb Adit Ranadive 2016-10-02 852 "pci_set_consistent_dma_mask failed\n");
29c8d9eb Adit Ranadive 2016-10-02 853 goto err_free_resource;
29c8d9eb Adit Ranadive 2016-10-02 854 }
29c8d9eb Adit Ranadive 2016-10-02 855 } else {
29c8d9eb Adit Ranadive 2016-10-02 856 ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
29c8d9eb Adit Ranadive 2016-10-02 857 if (ret != 0) {
29c8d9eb Adit Ranadive 2016-10-02 858 dev_err(&pdev->dev,
29c8d9eb Adit Ranadive 2016-10-02 859 "pci_set_dma_mask failed\n");
29c8d9eb Adit Ranadive 2016-10-02 860 goto err_free_resource;
29c8d9eb Adit Ranadive 2016-10-02 861 }
29c8d9eb Adit Ranadive 2016-10-02 862 }
29c8d9eb Adit Ranadive 2016-10-02 863
29c8d9eb Adit Ranadive 2016-10-02 864 pci_set_master(pdev);
29c8d9eb Adit Ranadive 2016-10-02 865
29c8d9eb Adit Ranadive 2016-10-02 866 /* Map register space */
29c8d9eb Adit Ranadive 2016-10-02 867 start = pci_resource_start(dev->pdev, PVRDMA_PCI_RESOURCE_REG);
29c8d9eb Adit Ranadive 2016-10-02 868 len = pci_resource_len(dev->pdev, PVRDMA_PCI_RESOURCE_REG);
29c8d9eb Adit Ranadive 2016-10-02 869 dev->regs = ioremap(start, len);
29c8d9eb Adit Ranadive 2016-10-02 870 if (!dev->regs) {
29c8d9eb Adit Ranadive 2016-10-02 871 dev_err(&pdev->dev, "register mapping failed\n");
29c8d9eb Adit Ranadive 2016-10-02 872 ret = -ENOMEM;
29c8d9eb Adit Ranadive 2016-10-02 873 goto err_free_resource;
29c8d9eb Adit Ranadive 2016-10-02 874 }
29c8d9eb Adit Ranadive 2016-10-02 875
29c8d9eb Adit Ranadive 2016-10-02 876 /* Setup per-device UAR. */
29c8d9eb Adit Ranadive 2016-10-02 877 dev->driver_uar.index = 0;
29c8d9eb Adit Ranadive 2016-10-02 878 dev->driver_uar.pfn =
29c8d9eb Adit Ranadive 2016-10-02 879 pci_resource_start(dev->pdev, PVRDMA_PCI_RESOURCE_UAR) >>
29c8d9eb Adit Ranadive 2016-10-02 880 PAGE_SHIFT;
29c8d9eb Adit Ranadive 2016-10-02 881 dev->driver_uar.map =
29c8d9eb Adit Ranadive 2016-10-02 882 ioremap(dev->driver_uar.pfn << PAGE_SHIFT, PAGE_SIZE);
29c8d9eb Adit Ranadive 2016-10-02 883 if (!dev->driver_uar.map) {
29c8d9eb Adit Ranadive 2016-10-02 884 dev_err(&pdev->dev, "failed to remap UAR pages\n");
29c8d9eb Adit Ranadive 2016-10-02 885 ret = -ENOMEM;
29c8d9eb Adit Ranadive 2016-10-02 886 goto err_unmap_regs;
29c8d9eb Adit Ranadive 2016-10-02 887 }
29c8d9eb Adit Ranadive 2016-10-02 888
05297b66 Bryan Tan 2017-08-22 889 dev->dsr_version = pvrdma_read_reg(dev, PVRDMA_REG_VERSION);
29c8d9eb Adit Ranadive 2016-10-02 890 dev_info(&pdev->dev, "device version %d, driver version %d\n",
05297b66 Bryan Tan 2017-08-22 891 dev->dsr_version, PVRDMA_VERSION);
29c8d9eb Adit Ranadive 2016-10-02 892
58355656 Himanshu Jha 2017-12-31 893 dev->dsr = dma_zalloc_coherent(&pdev->dev, sizeof(*dev->dsr),
29c8d9eb Adit Ranadive 2016-10-02 894 &dev->dsrbase, GFP_KERNEL);
29c8d9eb Adit Ranadive 2016-10-02 895 if (!dev->dsr) {
29c8d9eb Adit Ranadive 2016-10-02 896 dev_err(&pdev->dev, "failed to allocate shared region\n");
29c8d9eb Adit Ranadive 2016-10-02 897 ret = -ENOMEM;
29c8d9eb Adit Ranadive 2016-10-02 898 goto err_uar_unmap;
29c8d9eb Adit Ranadive 2016-10-02 899 }
29c8d9eb Adit Ranadive 2016-10-02 900
29c8d9eb Adit Ranadive 2016-10-02 901 /* Setup the shared region */
29c8d9eb Adit Ranadive 2016-10-02 902 dev->dsr->driver_version = PVRDMA_VERSION;
29c8d9eb Adit Ranadive 2016-10-02 903 dev->dsr->gos_info.gos_bits = sizeof(void *) == 4 ?
29c8d9eb Adit Ranadive 2016-10-02 904 PVRDMA_GOS_BITS_32 :
29c8d9eb Adit Ranadive 2016-10-02 905 PVRDMA_GOS_BITS_64;
29c8d9eb Adit Ranadive 2016-10-02 906 dev->dsr->gos_info.gos_type = PVRDMA_GOS_TYPE_LINUX;
29c8d9eb Adit Ranadive 2016-10-02 907 dev->dsr->gos_info.gos_ver = 1;
29c8d9eb Adit Ranadive 2016-10-02 908 dev->dsr->uar_pfn = dev->driver_uar.pfn;
29c8d9eb Adit Ranadive 2016-10-02 909
29c8d9eb Adit Ranadive 2016-10-02 910 /* Command slot. */
29c8d9eb Adit Ranadive 2016-10-02 911 dev->cmd_slot = dma_alloc_coherent(&pdev->dev, PAGE_SIZE,
29c8d9eb Adit Ranadive 2016-10-02 912 &slot_dma, GFP_KERNEL);
29c8d9eb Adit Ranadive 2016-10-02 913 if (!dev->cmd_slot) {
29c8d9eb Adit Ranadive 2016-10-02 914 ret = -ENOMEM;
29c8d9eb Adit Ranadive 2016-10-02 915 goto err_free_dsr;
29c8d9eb Adit Ranadive 2016-10-02 916 }
29c8d9eb Adit Ranadive 2016-10-02 917
29c8d9eb Adit Ranadive 2016-10-02 918 dev->dsr->cmd_slot_dma = (u64)slot_dma;
29c8d9eb Adit Ranadive 2016-10-02 919
29c8d9eb Adit Ranadive 2016-10-02 920 /* Response slot. */
29c8d9eb Adit Ranadive 2016-10-02 921 dev->resp_slot = dma_alloc_coherent(&pdev->dev, PAGE_SIZE,
29c8d9eb Adit Ranadive 2016-10-02 922 &slot_dma, GFP_KERNEL);
29c8d9eb Adit Ranadive 2016-10-02 923 if (!dev->resp_slot) {
29c8d9eb Adit Ranadive 2016-10-02 924 ret = -ENOMEM;
29c8d9eb Adit Ranadive 2016-10-02 925 goto err_free_slots;
29c8d9eb Adit Ranadive 2016-10-02 926 }
29c8d9eb Adit Ranadive 2016-10-02 927
29c8d9eb Adit Ranadive 2016-10-02 928 dev->dsr->resp_slot_dma = (u64)slot_dma;
29c8d9eb Adit Ranadive 2016-10-02 929
29c8d9eb Adit Ranadive 2016-10-02 930 /* Async event ring */
6332dee8 Adit Ranadive 2017-02-22 931 dev->dsr->async_ring_pages.num_pages = PVRDMA_NUM_RING_PAGES;
29c8d9eb Adit Ranadive 2016-10-02 932 ret = pvrdma_page_dir_init(dev, &dev->async_pdir,
29c8d9eb Adit Ranadive 2016-10-02 933 dev->dsr->async_ring_pages.num_pages, true);
29c8d9eb Adit Ranadive 2016-10-02 934 if (ret)
29c8d9eb Adit Ranadive 2016-10-02 935 goto err_free_slots;
29c8d9eb Adit Ranadive 2016-10-02 936 dev->async_ring_state = dev->async_pdir.pages[0];
29c8d9eb Adit Ranadive 2016-10-02 937 dev->dsr->async_ring_pages.pdir_dma = dev->async_pdir.dir_dma;
29c8d9eb Adit Ranadive 2016-10-02 938
29c8d9eb Adit Ranadive 2016-10-02 939 /* CQ notification ring */
6332dee8 Adit Ranadive 2017-02-22 940 dev->dsr->cq_ring_pages.num_pages = PVRDMA_NUM_RING_PAGES;
29c8d9eb Adit Ranadive 2016-10-02 941 ret = pvrdma_page_dir_init(dev, &dev->cq_pdir,
29c8d9eb Adit Ranadive 2016-10-02 942 dev->dsr->cq_ring_pages.num_pages, true);
29c8d9eb Adit Ranadive 2016-10-02 943 if (ret)
29c8d9eb Adit Ranadive 2016-10-02 944 goto err_free_async_ring;
29c8d9eb Adit Ranadive 2016-10-02 945 dev->cq_ring_state = dev->cq_pdir.pages[0];
29c8d9eb Adit Ranadive 2016-10-02 946 dev->dsr->cq_ring_pages.pdir_dma = dev->cq_pdir.dir_dma;
29c8d9eb Adit Ranadive 2016-10-02 947
29c8d9eb Adit Ranadive 2016-10-02 948 /*
29c8d9eb Adit Ranadive 2016-10-02 949 * Write the PA of the shared region to the device. The writes must be
29c8d9eb Adit Ranadive 2016-10-02 950 * ordered such that the high bits are written last. When the writes
29c8d9eb Adit Ranadive 2016-10-02 951 * complete, the device will have filled out the capabilities.
29c8d9eb Adit Ranadive 2016-10-02 952 */
29c8d9eb Adit Ranadive 2016-10-02 953
29c8d9eb Adit Ranadive 2016-10-02 954 pvrdma_write_reg(dev, PVRDMA_REG_DSRLOW, (u32)dev->dsrbase);
29c8d9eb Adit Ranadive 2016-10-02 955 pvrdma_write_reg(dev, PVRDMA_REG_DSRHIGH,
29c8d9eb Adit Ranadive 2016-10-02 956 (u32)((u64)(dev->dsrbase) >> 32));
29c8d9eb Adit Ranadive 2016-10-02 957
29c8d9eb Adit Ranadive 2016-10-02 958 /* Make sure the write is complete before reading status. */
29c8d9eb Adit Ranadive 2016-10-02 959 mb();
29c8d9eb Adit Ranadive 2016-10-02 960
05297b66 Bryan Tan 2017-08-22 961 /* The driver supports RoCE V1 and V2. */
05297b66 Bryan Tan 2017-08-22 962 if (!PVRDMA_SUPPORTED(dev)) {
05297b66 Bryan Tan 2017-08-22 963 dev_err(&pdev->dev, "driver needs RoCE v1 or v2 support\n");
29c8d9eb Adit Ranadive 2016-10-02 964 ret = -EFAULT;
29c8d9eb Adit Ranadive 2016-10-02 965 goto err_free_cq_ring;
29c8d9eb Adit Ranadive 2016-10-02 966 }
29c8d9eb Adit Ranadive 2016-10-02 967
29c8d9eb Adit Ranadive 2016-10-02 968 /* Paired vmxnet3 will have same bus, slot. But func will be 0 */
29c8d9eb Adit Ranadive 2016-10-02 969 pdev_net = pci_get_slot(pdev->bus, PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
29c8d9eb Adit Ranadive 2016-10-02 970 if (!pdev_net) {
29c8d9eb Adit Ranadive 2016-10-02 971 dev_err(&pdev->dev, "failed to find paired net device\n");
29c8d9eb Adit Ranadive 2016-10-02 972 ret = -ENODEV;
29c8d9eb Adit Ranadive 2016-10-02 973 goto err_free_cq_ring;
29c8d9eb Adit Ranadive 2016-10-02 974 }
29c8d9eb Adit Ranadive 2016-10-02 975
29c8d9eb Adit Ranadive 2016-10-02 976 if (pdev_net->vendor != PCI_VENDOR_ID_VMWARE ||
29c8d9eb Adit Ranadive 2016-10-02 977 pdev_net->device != PCI_DEVICE_ID_VMWARE_VMXNET3) {
29c8d9eb Adit Ranadive 2016-10-02 978 dev_err(&pdev->dev, "failed to find paired vmxnet3 device\n");
29c8d9eb Adit Ranadive 2016-10-02 979 pci_dev_put(pdev_net);
29c8d9eb Adit Ranadive 2016-10-02 980 ret = -ENODEV;
29c8d9eb Adit Ranadive 2016-10-02 981 goto err_free_cq_ring;
29c8d9eb Adit Ranadive 2016-10-02 982 }
29c8d9eb Adit Ranadive 2016-10-02 983
29c8d9eb Adit Ranadive 2016-10-02 984 dev->netdev = pci_get_drvdata(pdev_net);
d5bb424e Neil Horman 2018-06-28 @985 dev_hold(dev->netdev);
^^^^^^^^^^^^^^^^^^^^^
Dereferenced inside the function
29c8d9eb Adit Ranadive 2016-10-02 986 pci_dev_put(pdev_net);
29c8d9eb Adit Ranadive 2016-10-02 @987 if (!dev->netdev) {
^^^^^^^^^^^
Checked too late.
29c8d9eb Adit Ranadive 2016-10-02 988 dev_err(&pdev->dev, "failed to get vmxnet3 device\n");
29c8d9eb Adit Ranadive 2016-10-02 989 ret = -ENODEV;
29c8d9eb Adit Ranadive 2016-10-02 990 goto err_free_cq_ring;
29c8d9eb Adit Ranadive 2016-10-02 991 }
29c8d9eb Adit Ranadive 2016-10-02 992
29c8d9eb Adit Ranadive 2016-10-02 993 dev_info(&pdev->dev, "paired device to %s\n", dev->netdev->name);
29c8d9eb Adit Ranadive 2016-10-02 994
29c8d9eb Adit Ranadive 2016-10-02 995 /* Interrupt setup */
29c8d9eb Adit Ranadive 2016-10-02 996 ret = pvrdma_alloc_intrs(dev);
29c8d9eb Adit Ranadive 2016-10-02 997 if (ret) {
29c8d9eb Adit Ranadive 2016-10-02 998 dev_err(&pdev->dev, "failed to allocate interrupts\n");
29c8d9eb Adit Ranadive 2016-10-02 999 ret = -ENOMEM;
ff89b070 Adit Ranadive 2017-01-19 1000 goto err_free_cq_ring;
29c8d9eb Adit Ranadive 2016-10-02 1001 }
29c8d9eb Adit Ranadive 2016-10-02 1002
29c8d9eb Adit Ranadive 2016-10-02 1003 /* Allocate UAR table. */
29c8d9eb Adit Ranadive 2016-10-02 1004 ret = pvrdma_uar_table_init(dev);
29c8d9eb Adit Ranadive 2016-10-02 1005 if (ret) {
29c8d9eb Adit Ranadive 2016-10-02 1006 dev_err(&pdev->dev, "failed to allocate UAR table\n");
29c8d9eb Adit Ranadive 2016-10-02 1007 ret = -ENOMEM;
29c8d9eb Adit Ranadive 2016-10-02 1008 goto err_free_intrs;
29c8d9eb Adit Ranadive 2016-10-02 1009 }
29c8d9eb Adit Ranadive 2016-10-02 1010
29c8d9eb Adit Ranadive 2016-10-02 1011 /* Allocate GID table */
29c8d9eb Adit Ranadive 2016-10-02 1012 dev->sgid_tbl = kcalloc(dev->dsr->caps.gid_tbl_len,
29c8d9eb Adit Ranadive 2016-10-02 1013 sizeof(union ib_gid), GFP_KERNEL);
29c8d9eb Adit Ranadive 2016-10-02 1014 if (!dev->sgid_tbl) {
29c8d9eb Adit Ranadive 2016-10-02 1015 ret = -ENOMEM;
29c8d9eb Adit Ranadive 2016-10-02 1016 goto err_free_uar_table;
29c8d9eb Adit Ranadive 2016-10-02 1017 }
29c8d9eb Adit Ranadive 2016-10-02 1018 dev_dbg(&pdev->dev, "gid table len %d\n", dev->dsr->caps.gid_tbl_len);
29c8d9eb Adit Ranadive 2016-10-02 1019
29c8d9eb Adit Ranadive 2016-10-02 1020 pvrdma_enable_intrs(dev);
29c8d9eb Adit Ranadive 2016-10-02 1021
29c8d9eb Adit Ranadive 2016-10-02 1022 /* Activate pvrdma device */
29c8d9eb Adit Ranadive 2016-10-02 1023 pvrdma_write_reg(dev, PVRDMA_REG_CTL, PVRDMA_DEVICE_CTL_ACTIVATE);
29c8d9eb Adit Ranadive 2016-10-02 1024
29c8d9eb Adit Ranadive 2016-10-02 1025 /* Make sure the write is complete before reading status. */
29c8d9eb Adit Ranadive 2016-10-02 1026 mb();
29c8d9eb Adit Ranadive 2016-10-02 1027
29c8d9eb Adit Ranadive 2016-10-02 1028 /* Check if device was successfully activated */
29c8d9eb Adit Ranadive 2016-10-02 1029 ret = pvrdma_read_reg(dev, PVRDMA_REG_ERR);
29c8d9eb Adit Ranadive 2016-10-02 1030 if (ret != 0) {
29c8d9eb Adit Ranadive 2016-10-02 1031 dev_err(&pdev->dev, "failed to activate device\n");
29c8d9eb Adit Ranadive 2016-10-02 1032 ret = -EFAULT;
29c8d9eb Adit Ranadive 2016-10-02 1033 goto err_disable_intr;
29c8d9eb Adit Ranadive 2016-10-02 1034 }
29c8d9eb Adit Ranadive 2016-10-02 1035
29c8d9eb Adit Ranadive 2016-10-02 1036 /* Register IB device */
29c8d9eb Adit Ranadive 2016-10-02 1037 ret = pvrdma_register_device(dev);
29c8d9eb Adit Ranadive 2016-10-02 1038 if (ret) {
29c8d9eb Adit Ranadive 2016-10-02 1039 dev_err(&pdev->dev, "failed to register IB device\n");
29c8d9eb Adit Ranadive 2016-10-02 1040 goto err_disable_intr;
29c8d9eb Adit Ranadive 2016-10-02 1041 }
29c8d9eb Adit Ranadive 2016-10-02 1042
29c8d9eb Adit Ranadive 2016-10-02 1043 dev->nb_netdev.notifier_call = pvrdma_netdevice_event;
29c8d9eb Adit Ranadive 2016-10-02 1044 ret = register_netdevice_notifier(&dev->nb_netdev);
29c8d9eb Adit Ranadive 2016-10-02 1045 if (ret) {
29c8d9eb Adit Ranadive 2016-10-02 1046 dev_err(&pdev->dev, "failed to register netdevice events\n");
29c8d9eb Adit Ranadive 2016-10-02 1047 goto err_unreg_ibdev;
29c8d9eb Adit Ranadive 2016-10-02 1048 }
29c8d9eb Adit Ranadive 2016-10-02 1049
29c8d9eb Adit Ranadive 2016-10-02 1050 dev_info(&pdev->dev, "attached to device\n");
29c8d9eb Adit Ranadive 2016-10-02 1051 return 0;
29c8d9eb Adit Ranadive 2016-10-02 1052
29c8d9eb Adit Ranadive 2016-10-02 1053 err_unreg_ibdev:
29c8d9eb Adit Ranadive 2016-10-02 1054 ib_unregister_device(&dev->ib_dev);
29c8d9eb Adit Ranadive 2016-10-02 1055 err_disable_intr:
29c8d9eb Adit Ranadive 2016-10-02 1056 pvrdma_disable_intrs(dev);
29c8d9eb Adit Ranadive 2016-10-02 1057 kfree(dev->sgid_tbl);
29c8d9eb Adit Ranadive 2016-10-02 1058 err_free_uar_table:
29c8d9eb Adit Ranadive 2016-10-02 1059 pvrdma_uar_table_cleanup(dev);
29c8d9eb Adit Ranadive 2016-10-02 1060 err_free_intrs:
29c8d9eb Adit Ranadive 2016-10-02 1061 pvrdma_free_irq(dev);
7bf3976d Christoph Hellwig 2017-02-15 1062 pci_free_irq_vectors(pdev);
29c8d9eb Adit Ranadive 2016-10-02 1063 err_free_cq_ring:
29c8d9eb Adit Ranadive 2016-10-02 1064 pvrdma_page_dir_cleanup(dev, &dev->cq_pdir);
29c8d9eb Adit Ranadive 2016-10-02 1065 err_free_async_ring:
29c8d9eb Adit Ranadive 2016-10-02 1066 pvrdma_page_dir_cleanup(dev, &dev->async_pdir);
29c8d9eb Adit Ranadive 2016-10-02 1067 err_free_slots:
29c8d9eb Adit Ranadive 2016-10-02 1068 pvrdma_free_slots(dev);
29c8d9eb Adit Ranadive 2016-10-02 1069 err_free_dsr:
29c8d9eb Adit Ranadive 2016-10-02 1070 dma_free_coherent(&pdev->dev, sizeof(*dev->dsr), dev->dsr,
29c8d9eb Adit Ranadive 2016-10-02 1071 dev->dsrbase);
29c8d9eb Adit Ranadive 2016-10-02 1072 err_uar_unmap:
29c8d9eb Adit Ranadive 2016-10-02 1073 iounmap(dev->driver_uar.map);
29c8d9eb Adit Ranadive 2016-10-02 1074 err_unmap_regs:
29c8d9eb Adit Ranadive 2016-10-02 1075 iounmap(dev->regs);
29c8d9eb Adit Ranadive 2016-10-02 1076 err_free_resource:
29c8d9eb Adit Ranadive 2016-10-02 1077 pci_release_regions(pdev);
29c8d9eb Adit Ranadive 2016-10-02 1078 err_disable_pdev:
29c8d9eb Adit Ranadive 2016-10-02 1079 pci_disable_device(pdev);
29c8d9eb Adit Ranadive 2016-10-02 1080 pci_set_drvdata(pdev, NULL);
29c8d9eb Adit Ranadive 2016-10-02 1081 err_free_device:
29c8d9eb Adit Ranadive 2016-10-02 1082 mutex_lock(&pvrdma_device_list_lock);
29c8d9eb Adit Ranadive 2016-10-02 1083 list_del(&dev->device_link);
29c8d9eb Adit Ranadive 2016-10-02 1084 mutex_unlock(&pvrdma_device_list_lock);
29c8d9eb Adit Ranadive 2016-10-02 1085 ib_dealloc_device(&dev->ib_dev);
29c8d9eb Adit Ranadive 2016-10-02 1086 return ret;
29c8d9eb Adit Ranadive 2016-10-02 1087 }
29c8d9eb Adit Ranadive 2016-10-02 1088
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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On Sat, Jun 30, 2018 at 10:15:07PM +0300, Dan Carpenter wrote: > Hi Neil, > > I love your patch! Perhaps something to improve: > > url: https://github.com/0day-ci/linux/commits/Neil-Horman/vmw_pvrdma-Release-netdev-when-vmxnet3-module-is-removed/20180628-232414 > > smatch warnings: > drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c:987 pvrdma_pci_probe() warn: variable dereferenced before check 'dev->netdev' (see line 985) > Appreciate the smatch check, but this was caught by visual review and fixed in V2 already. Best Neil -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c index 0be33a81bbe6..5b4782078a74 100644 --- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c +++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c @@ -699,8 +699,12 @@ static int pvrdma_del_gid(const struct ib_gid_attr *attr, void **context) } static void pvrdma_netdevice_event_handle(struct pvrdma_dev *dev, + struct net_device *ndev, unsigned long event) { + struct pci_dev *pdev_net; + + switch (event) { case NETDEV_REBOOT: case NETDEV_DOWN: @@ -718,6 +722,21 @@ static void pvrdma_netdevice_event_handle(struct pvrdma_dev *dev, else pvrdma_dispatch_event(dev, 1, IB_EVENT_PORT_ACTIVE); break; + case NETDEV_UNREGISTER: + dev_put(dev->netdev); + dev->netdev = NULL; + break; + case NETDEV_REGISTER: + /* Paired vmxnet3 will have same bus, slot. But func will be 0 */ + pdev_net = pci_get_slot(dev->pdev->bus, PCI_DEVFN(PCI_SLOT(dev->pdev->devfn), 0)); + if ((dev->netdev == NULL) && (pci_get_drvdata(pdev_net) == ndev)) { + /* this is our netdev */ + dev->netdev = ndev; + dev_hold(ndev); + } + pci_dev_put(pdev_net); + break; + default: dev_dbg(&dev->pdev->dev, "ignore netdevice event %ld on %s\n", event, dev->ib_dev.name); @@ -734,8 +753,9 @@ static void pvrdma_netdevice_event_work(struct work_struct *work) mutex_lock(&pvrdma_device_list_lock); list_for_each_entry(dev, &pvrdma_device_list, device_link) { - if (dev->netdev == netdev_work->event_netdev) { - pvrdma_netdevice_event_handle(dev, netdev_work->event); + if ((netdev_work->event == NETDEV_REGISTER) || + (dev->netdev == netdev_work->event_netdev)) { + pvrdma_netdevice_event_handle(dev, netdev_work->event_netdev, netdev_work->event); break; } } @@ -962,6 +982,7 @@ static int pvrdma_pci_probe(struct pci_dev *pdev, } dev->netdev = pci_get_drvdata(pdev_net); + dev_hold(dev->netdev); pci_dev_put(pdev_net); if (!dev->netdev) { dev_err(&pdev->dev, "failed to get vmxnet3 device\n");
On repeated module load/unload cycles, its possible for the pvrmda driver to encounter this crash: ... 297.032448] RIP: 0010:[<ffffffff839e4620>] [<ffffffff839e4620>] netdev_walk_all_upper_dev_rcu+0x50/0xb0 [ 297.034078] RSP: 0018:ffff95087780bd08 EFLAGS: 00010286 [ 297.034986] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff95087a0c0000 [ 297.036196] RDX: ffff95087a0c0000 RSI: ffffffff839e44e0 RDI: ffff950835d0c000 [ 297.037421] RBP: ffff95087780bd40 R08: ffff95087a0e0ea0 R09: abddacd03f8e0ea0 [ 297.038636] R10: abddacd03f8e0ea0 R11: ffffef5901e9dbc0 R12: ffff95087a0c0000 [ 297.039854] R13: ffffffff839e44e0 R14: ffff95087a0c0000 R15: ffff950835d0c828 [ 297.041071] FS: 0000000000000000(0000) GS:ffff95087fc00000(0000) knlGS:0000000000000000 [ 297.042443] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 297.043429] CR2: ffffffffffffffe8 CR3: 000000007a652000 CR4: 00000000003607f0 [ 297.044674] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 297.045893] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 297.047109] Call Trace: [ 297.047545] [<ffffffff839e4698>] netdev_has_upper_dev_all_rcu+0x18/0x20 [ 297.048691] [<ffffffffc05d31af>] is_eth_port_of_netdev+0x2f/0xa0 [ib_core] [ 297.049886] [<ffffffffc05d3180>] ? is_eth_active_slave_of_bonding_rcu+0x70/0x70 [ib_core] ... This occurs because vmw_pvrdma on probe stores a pointer to the netdev that exists on function 0 of the same bus/device/slot (which represents the vmxnet3 ethernet driver). However, it never removes this pointer if the vmxnet3 module is removed, leading to crashes resulting from use after free dereferencing incidents like the one above. The fix is pretty straightforward. vmw_pvrdma should listen for NETDEV_REGISTER and NETDEV_UNREGISTER events in its event listener code block, and update the stored netdev pointer accordingly. This solution has been tested by myself and the reporter with successful results. This fix also allows the pvrdma driver to find its underlying ethernet device in the event that vmxnet3 is loaded after pvrdma, which it was not able to do before. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: ruquin@redhat.com CC: Adit Ranadive <aditr@vmware.com> CC: VMware PV-Drivers <pv-drivers@vmware.com> CC: Doug Ledford <dledford@redhat.com> CC: Jason Gunthorpe <jgg@ziepe.ca> CC: linux-kernel@vger.kernel.org --- .../infiniband/hw/vmw_pvrdma/pvrdma_main.c | 25 +++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-)