The commit 05f151a73ec2 itself is correct, but it exposes this
use-after-free bug, which is caught by some memory debug options.
Add a Fixes tag to indicate the dependency.
Fixes: 05f151a73ec2 ("PCI: hv: Fix a memory leak in hv_eject_device_work()")
Signed-off-by: Dexuan Cui <[email protected]>
Cc: [email protected]
---
In v2:
Replaced "hpdev->hbus" with "hbus", since we have the new "hbus" variable. [Michael Kelley]
drivers/pci/controller/pci-hyperv.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 808a182830e5..5dadc964ad3b 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -1880,6 +1880,7 @@ static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
static void hv_eject_device_work(struct work_struct *work)
{
struct pci_eject_response *ejct_pkt;
+ struct hv_pcibus_device *hbus;
struct hv_pci_dev *hpdev;
struct pci_dev *pdev;
unsigned long flags;
@@ -1890,6 +1891,7 @@ static void hv_eject_device_work(struct work_struct *work)
} ctxt;
hpdev = container_of(work, struct hv_pci_dev, wrk);
+ hbus = hpdev->hbus;
WARN_ON(hpdev->state != hv_pcichild_ejecting);
@@ -1900,8 +1902,7 @@ static void hv_eject_device_work(struct work_struct *work)
* because hbus->pci_bus may not exist yet.
*/
wslot = wslot_to_devfn(hpdev->desc.win_slot.slot);
- pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0,
- wslot);
+ pdev = pci_get_domain_bus_and_slot(hbus->sysdata.domain, 0, wslot);
if (pdev) {
pci_lock_rescan_remove();
pci_stop_and_remove_bus_device(pdev);
@@ -1909,9 +1910,9 @@ static void hv_eject_device_work(struct work_struct *work)
pci_unlock_rescan_remove();
}
- spin_lock_irqsave(&hpdev->hbus->device_list_lock, flags);
+ spin_lock_irqsave(&hbus->device_list_lock, flags);
list_del(&hpdev->list_entry);
- spin_unlock_irqrestore(&hpdev->hbus->device_list_lock, flags);
+ spin_unlock_irqrestore(&hbus->device_list_lock, flags);
if (hpdev->pci_slot)
pci_destroy_slot(hpdev->pci_slot);
@@ -1920,7 +1921,7 @@ static void hv_eject_device_work(struct work_struct *work)
ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot;
- vmbus_sendpacket(hpdev->hbus->hdev->channel, ejct_pkt,
+ vmbus_sendpacket(hbus->hdev->channel, ejct_pkt,
sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
VM_PKT_DATA_INBAND, 0);
@@ -1929,7 +1930,9 @@ static void hv_eject_device_work(struct work_struct *work)
/* For the two refs got in new_pcichild_device() */
put_pcichild(hpdev);
put_pcichild(hpdev);
- put_hvpcibus(hpdev->hbus);
+ /* hpdev has been freed. Do not use it any more. */
+
+ put_hvpcibus(hbus);
}
/**
--
2.17.1
From: Dexuan Cui <[email protected]> Sent: Friday, June 21, 2019 4:45 PM
>
> The commit 05f151a73ec2 itself is correct, but it exposes this
> use-after-free bug, which is caught by some memory debug options.
>
> Add a Fixes tag to indicate the dependency.
>
> Fixes: 05f151a73ec2 ("PCI: hv: Fix a memory leak in hv_eject_device_work()")
> Signed-off-by: Dexuan Cui <[email protected]>
> Cc: [email protected]
> ---
>
> In v2:
> Replaced "hpdev->hbus" with "hbus", since we have the new "hbus" variable. [Michael
> Kelley]
>
> drivers/pci/controller/pci-hyperv.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index 808a182830e5..5dadc964ad3b 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -1880,6 +1880,7 @@ static void hv_pci_devices_present(struct hv_pcibus_device
> *hbus,
> static void hv_eject_device_work(struct work_struct *work)
> {
> struct pci_eject_response *ejct_pkt;
> + struct hv_pcibus_device *hbus;
> struct hv_pci_dev *hpdev;
> struct pci_dev *pdev;
> unsigned long flags;
> @@ -1890,6 +1891,7 @@ static void hv_eject_device_work(struct work_struct *work)
> } ctxt;
>
> hpdev = container_of(work, struct hv_pci_dev, wrk);
> + hbus = hpdev->hbus;
>
> WARN_ON(hpdev->state != hv_pcichild_ejecting);
>
> @@ -1900,8 +1902,7 @@ static void hv_eject_device_work(struct work_struct *work)
> * because hbus->pci_bus may not exist yet.
> */
> wslot = wslot_to_devfn(hpdev->desc.win_slot.slot);
> - pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0,
> - wslot);
> + pdev = pci_get_domain_bus_and_slot(hbus->sysdata.domain, 0, wslot);
> if (pdev) {
> pci_lock_rescan_remove();
> pci_stop_and_remove_bus_device(pdev);
> @@ -1909,9 +1910,9 @@ static void hv_eject_device_work(struct work_struct *work)
> pci_unlock_rescan_remove();
> }
>
> - spin_lock_irqsave(&hpdev->hbus->device_list_lock, flags);
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> list_del(&hpdev->list_entry);
> - spin_unlock_irqrestore(&hpdev->hbus->device_list_lock, flags);
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
>
> if (hpdev->pci_slot)
> pci_destroy_slot(hpdev->pci_slot);
> @@ -1920,7 +1921,7 @@ static void hv_eject_device_work(struct work_struct *work)
> ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
> ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
> ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot;
> - vmbus_sendpacket(hpdev->hbus->hdev->channel, ejct_pkt,
> + vmbus_sendpacket(hbus->hdev->channel, ejct_pkt,
> sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
> VM_PKT_DATA_INBAND, 0);
>
> @@ -1929,7 +1930,9 @@ static void hv_eject_device_work(struct work_struct *work)
> /* For the two refs got in new_pcichild_device() */
> put_pcichild(hpdev);
> put_pcichild(hpdev);
> - put_hvpcibus(hpdev->hbus);
> + /* hpdev has been freed. Do not use it any more. */
> +
> + put_hvpcibus(hbus);
> }
>
> /**
> --
> 2.17.1
Reviewed-by: Michael Kelley <[email protected]>
On Fri, Jun 21, 2019 at 11:45:23PM +0000, Dexuan Cui wrote:
>
> The commit 05f151a73ec2 itself is correct, but it exposes this
> use-after-free bug, which is caught by some memory debug options.
>
> Add a Fixes tag to indicate the dependency.
>
> Fixes: 05f151a73ec2 ("PCI: hv: Fix a memory leak in hv_eject_device_work()")
> Signed-off-by: Dexuan Cui <[email protected]>
> Cc: [email protected]
> ---
>
> In v2:
> Replaced "hpdev->hbus" with "hbus", since we have the new "hbus" variable. [Michael Kelley]
>
> drivers/pci/controller/pci-hyperv.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
Applied to pci/hv for v5.3, thanks.
Lorenzo
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index 808a182830e5..5dadc964ad3b 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -1880,6 +1880,7 @@ static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
> static void hv_eject_device_work(struct work_struct *work)
> {
> struct pci_eject_response *ejct_pkt;
> + struct hv_pcibus_device *hbus;
> struct hv_pci_dev *hpdev;
> struct pci_dev *pdev;
> unsigned long flags;
> @@ -1890,6 +1891,7 @@ static void hv_eject_device_work(struct work_struct *work)
> } ctxt;
>
> hpdev = container_of(work, struct hv_pci_dev, wrk);
> + hbus = hpdev->hbus;
>
> WARN_ON(hpdev->state != hv_pcichild_ejecting);
>
> @@ -1900,8 +1902,7 @@ static void hv_eject_device_work(struct work_struct *work)
> * because hbus->pci_bus may not exist yet.
> */
> wslot = wslot_to_devfn(hpdev->desc.win_slot.slot);
> - pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0,
> - wslot);
> + pdev = pci_get_domain_bus_and_slot(hbus->sysdata.domain, 0, wslot);
> if (pdev) {
> pci_lock_rescan_remove();
> pci_stop_and_remove_bus_device(pdev);
> @@ -1909,9 +1910,9 @@ static void hv_eject_device_work(struct work_struct *work)
> pci_unlock_rescan_remove();
> }
>
> - spin_lock_irqsave(&hpdev->hbus->device_list_lock, flags);
> + spin_lock_irqsave(&hbus->device_list_lock, flags);
> list_del(&hpdev->list_entry);
> - spin_unlock_irqrestore(&hpdev->hbus->device_list_lock, flags);
> + spin_unlock_irqrestore(&hbus->device_list_lock, flags);
>
> if (hpdev->pci_slot)
> pci_destroy_slot(hpdev->pci_slot);
> @@ -1920,7 +1921,7 @@ static void hv_eject_device_work(struct work_struct *work)
> ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
> ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
> ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot;
> - vmbus_sendpacket(hpdev->hbus->hdev->channel, ejct_pkt,
> + vmbus_sendpacket(hbus->hdev->channel, ejct_pkt,
> sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
> VM_PKT_DATA_INBAND, 0);
>
> @@ -1929,7 +1930,9 @@ static void hv_eject_device_work(struct work_struct *work)
> /* For the two refs got in new_pcichild_device() */
> put_pcichild(hpdev);
> put_pcichild(hpdev);
> - put_hvpcibus(hpdev->hbus);
> + /* hpdev has been freed. Do not use it any more. */
> +
> + put_hvpcibus(hbus);
> }
>
> /**
> --
> 2.17.1
>