* RE: FAILED: patch "[PATCH] PCI: hv: Fix a use-after-free bug in hv_eject_device_work()" failed to apply to 4.9-stable tree
2019-07-23 11:59 FAILED: patch "[PATCH] PCI: hv: Fix a use-after-free bug in hv_eject_device_work()" failed to apply to 4.9-stable tree gregkh
@ 2019-07-24 0:59 ` Dexuan Cui
2019-07-24 12:02 ` gregkh
0 siblings, 1 reply; 3+ messages in thread
From: Dexuan Cui @ 2019-07-24 0:59 UTC (permalink / raw)
To: gregkh@linuxfoundation.org
Cc: stable@vger.kernel.org, lorenzo.pieralisi@arm.com, Michael Kelley
[-- Attachment #1: Type: text/plain, Size: 1318 bytes --]
> From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org>
> Sent: Tuesday, July 23, 2019 4:59 AM
> To: Dexuan Cui <decui@microsoft.com>; lorenzo.pieralisi@arm.com; Michael
> Kelley <mikelley@microsoft.com>
> Cc: stable@vger.kernel.org
> Subject: FAILED: patch "[PATCH] PCI: hv: Fix a use-after-free bug in
> hv_eject_device_work()" failed to apply to 4.9-stable tree
>
>
> The patch below does not apply to the 4.9-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
>
> thanks,
>
> greg k-h
>
> ------------------ original commit in Linus's tree ------------------
>
> From 4df591b20b80cb77920953812d894db259d85bd7 Mon Sep 17 00:00:00
> 2001
> From: Dexuan Cui <decui@microsoft.com>
> Date: Fri, 21 Jun 2019 23:45:23 +0000
> Subject: [PATCH] PCI: hv: Fix a use-after-free bug in hv_eject_device_work()
Hi,
To apply this patch to v4.9.186, we need to cherry-pick another patch first:
e74d2ebdda33 ("PCI: hv: Delete the device earlier from hbus->children for hot-remove")
Then I backported this commit (4df591b20)
Please see the two attachments for the two patches.
They can be cleanly applied to v4.9.186.
Thanks,
-- Dexuan
[-- Attachment #2: for-4.9.186-0001-PCI-hv-Delete-the-device-earlier-from-hbus-children-.patch --]
[-- Type: application/octet-stream, Size: 2416 bytes --]
From 70913034cdcf061020573d64d4890c3781c63b6b Mon Sep 17 00:00:00 2001
From: Dexuan Cui <decui@microsoft.com>
Date: Thu, 10 Nov 2016 07:19:52 +0000
Subject: [PATCH for-4.9.186 1/2] PCI: hv: Delete the device earlier from
hbus->children for hot-remove
Reply-To: decui@microsoft.com
[ Upstream commit e74d2ebdda33b3bdd1826b5b92e9aa45bdf92bb3 ]
After we send a PCI_EJECTION_COMPLETE message to the host, the host will
immediately send us a PCI_BUS_RELATIONS message with
relations->device_count == 0, so pci_devices_present_work(), running on
another thread, can find the being-ejected device, mark the
hpdev->reported_missing to true, and run list_move_tail()/list_del() for
the device -- this races hv_eject_device_work() -> list_del().
Move the list_del() in hv_eject_device_work() to an earlier place, i.e.,
before we send PCI_EJECTION_COMPLETE, so later the
pci_devices_present_work() can't see the device.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jake Oshins <jakeo@microsoft.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
---
drivers/pci/host/pci-hyperv.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 200b415..499461c 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1607,6 +1607,10 @@ static void hv_eject_device_work(struct work_struct *work)
pci_unlock_rescan_remove();
}
+ spin_lock_irqsave(&hpdev->hbus->device_list_lock, flags);
+ list_del(&hpdev->list_entry);
+ spin_unlock_irqrestore(&hpdev->hbus->device_list_lock, flags);
+
memset(&ctxt, 0, sizeof(ctxt));
ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
@@ -1615,10 +1619,6 @@ static void hv_eject_device_work(struct work_struct *work)
sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
VM_PKT_DATA_INBAND, 0);
- spin_lock_irqsave(&hpdev->hbus->device_list_lock, flags);
- list_del(&hpdev->list_entry);
- spin_unlock_irqrestore(&hpdev->hbus->device_list_lock, flags);
-
put_pcichild(hpdev, hv_pcidev_ref_childlist);
put_pcichild(hpdev, hv_pcidev_ref_initial);
put_pcichild(hpdev, hv_pcidev_ref_pnp);
--
1.8.3.1
[-- Attachment #3: for-4.9.186-0002-PCI-hv-Fix-a-use-after-free-bug-in-hv_eject_device_w.patch --]
[-- Type: application/octet-stream, Size: 3012 bytes --]
From ec241858c53dd7fdc98a8f4ee4719bf64e0677f8 Mon Sep 17 00:00:00 2001
From: Dexuan Cui <decui@microsoft.com>
Date: Tue, 23 Jul 2019 17:30:41 -0700
Subject: [PATCH for-4.9.186 2/2] PCI: hv: Fix a use-after-free bug in
hv_eject_device_work()
Reply-To: decui@microsoft.com
[ Upstream commit 4df591b20b80cb77920953812d894db259d85bd7 ]
Fix a use-after-free in hv_eject_device_work().
Fixes: 05f151a73ec2 ("PCI: hv: Fix a memory leak in hv_eject_device_work()")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dexuan Cui <decui@microsoft.com>
---
drivers/pci/host/pci-hyperv.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 499461c..a597619 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1575,6 +1575,7 @@ 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;
@@ -1585,6 +1586,7 @@ static void hv_eject_device_work(struct work_struct *work)
} ctxt;
hpdev = container_of(work, struct hv_pci_dev, wrk);
+ hbus = hpdev->hbus;
if (hpdev->state != hv_pcichild_ejecting) {
put_pcichild(hpdev, hv_pcidev_ref_pnp);
@@ -1598,8 +1600,7 @@ 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);
@@ -1607,22 +1608,24 @@ 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);
memset(&ctxt, 0, sizeof(ctxt));
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);
put_pcichild(hpdev, hv_pcidev_ref_childlist);
put_pcichild(hpdev, hv_pcidev_ref_initial);
put_pcichild(hpdev, hv_pcidev_ref_pnp);
- put_hvpcibus(hpdev->hbus);
+
+ /* hpdev has been freed. Do not use it any more. */
+ put_hvpcibus(hbus);
}
/**
--
1.8.3.1
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