[PATCH 2/2] nvme-pci: Fix UAF introduced by nvme_dev_remove_admin()

[Casey Chen]

nvme_dev_remove_admin() could free admin_q and admin_tagset while
they are being accessed by nvme_dev_disable(), which could come from
nvme_remove_dead_ctrl() by nvme_reset_work() during cleanup.

Commit cb4bfda62afa ("nvme-pci: fix hot removal during error handling") was
to avoid requests being stuck on a removed controller by killing admin queue.
But the later fix c8e9e9b7646e ("nvme-pci: unquiesce admin queue on shutdown"),
together with nvme_dev_disable(dev, true) right before nvme_dev_remove_admin()
could help dispatch requests and fail them early, so we don't need
nvme_dev_remove_admin() any more.

Fixes: cb4bfda62afa ("nvme-pci: fix hot removal during error handling")

upstream_status: upstream
---
 drivers/nvme/host/pci.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 5abc4c3be454..49ef2027bcb0 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -3023,7 +3023,6 @@ static void nvme_remove(struct pci_dev *pdev)
 	if (!pci_device_is_present(pdev)) {
 		nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DEAD);
 		nvme_dev_disable(dev, true);
-		nvme_dev_remove_admin(dev);
 	}
 
 	flush_work(&dev->ctrl.reset_work);
-- 
2.17.1