-----Original Message----- From: gregkh@linuxfoundation.org gregkh@linuxfoundation.org Sent: Tuesday, October 8, 2019 10:19 AM To: Dexuan Cui decui@microsoft.com; lorenzo.pieralisi@arm.com Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] PCI: hv: Avoid use of hv_pci_dev->pci_slot after freeing it" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-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 533ca1feed98b0bf024779a14760694c7cb4d431 Mon Sep 17 00:00:00 2001 From: Dexuan Cui decui@microsoft.com Date: Fri, 2 Aug 2019 22:50:20 +0000 Subject: [PATCH] PCI: hv: Avoid use of hv_pci_dev->pci_slot after freeing it

The slot must be removed before the pci_dev is removed, otherwise a panic can happen due to use-after-free.

Fixes: 15becc2b56c6 ("PCI: hv: Add hv_pci_remove_slots() when we unload the driver") Signed-off-by: Dexuan Cui decui@microsoft.com Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Cc: stable@vger.kernel.org

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index 40b625458afa..2b53976cd9f9 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -2701,8 +2701,8 @@ static int hv_pci_remove(struct hv_device *hdev) /* Remove the bus from PCI's point of view. */ pci_lock_rescan_remove(); pci_stop_root_bus(hbus->pci_bus);

• pci_remove_root_bus(hbus->pci_bus);
  

  hv_pci_remove_slots(hbus);

• pci_remove_root_bus(hbus->pci_bus);
  

  pci_unlock_rescan_remove(); hbus->state = hv_pcibus_removed; }

I can't understand why the mail is generated, because v4.19.78 has already included the commit 533ca1feed98 ("PCI: hv: Avoid use of hv_pci_dev->pci_slot after freeing it") by commit 08fdaee2d97bdd55e03308b563783b2612670e8b Author: Dexuan Cui decui@microsoft.com Date: Fri Aug 2 22:50:20 2019 +0000

PCI: hv: Avoid use of hv_pci_dev->pci_slot after freeing it

[ Upstream commit 533ca1feed98b0bf024779a14760694c7cb4d431 ]

The slot must be removed before the pci_dev is removed, otherwise a panic can happen due to use-after-free.

Fixes: 15becc2b56c6 ("PCI: hv: Add hv_pci_remove_slots() when we unload the driver") Signed-off-by: Dexuan Cui decui@microsoft.com Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin sashal@kernel.org

Looks I can ignore the mail.

Thanks, Dexuan