PCI: Fix use-after-free in pci_bus_release_domain_nr()

In the Linux kernel, the following vulnerability has been resolved:

PCI: Fix use-after-free in pci_bus_release_domain_nr()

Commit c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()")

introduced a use-after-free bug in the bus removal cleanup. The issue was

found with kfence:

[ 19.293351] BUG: KFENCE: use-after-free read in pci_bus_release_domain_nr+0x10/0x70

[ 19.302817] Use-after-free read at 0x000000007f3b80eb (in kfence-#115):

[ 19.309677] pci_bus_release_domain_nr+0x10/0x70

[ 19.309691] dw_pcie_host_deinit+0x28/0x78

[ 19.309702] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194]

[ 19.309734] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194]

[ 19.309752] platform_probe+0x90/0xd8

...

[ 19.311457] kfence-#115: 0x00000000063a155a-0x00000000ba698da8, size=1072, cache=kmalloc-2k

[ 19.311469] allocated by task 96 on cpu 10 at 19.279323s:

[ 19.311562] __kmem_cache_alloc_node+0x260/0x278

[ 19.311571] kmalloc_trace+0x24/0x30

[ 19.311580] pci_alloc_bus+0x24/0xa0

[ 19.311590] pci_register_host_bridge+0x48/0x4b8

[ 19.311601] pci_scan_root_bus_bridge+0xc0/0xe8

[ 19.311613] pci_host_probe+0x18/0xc0

[ 19.311623] dw_pcie_host_init+0x2c0/0x568

[ 19.311630] tegra_pcie_dw_probe+0x610/0xb28 [pcie_tegra194]

[ 19.311647] platform_probe+0x90/0xd8

...

[ 19.311782] freed by task 96 on cpu 10 at 19.285833s:

[ 19.311799] release_pcibus_dev+0x30/0x40

[ 19.311808] device_release+0x30/0x90

[ 19.311814] kobject_put+0xa8/0x120

[ 19.311832] device_unregister+0x20/0x30

[ 19.311839] pci_remove_bus+0x78/0x88

[ 19.311850] pci_remove_root_bus+0x5c/0x98

[ 19.311860] dw_pcie_host_deinit+0x28/0x78

[ 19.311866] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194]

[ 19.311883] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194]

[ 19.311900] platform_probe+0x90/0xd8

...

[ 19.313579] CPU: 10 PID: 96 Comm: kworker/u24:2 Not tainted 6.2.0 #4

[ 19.320171] Hardware name: /, BIOS 1.0-d7fb19b 08/10/2022

[ 19.325852] Workqueue: events_unbound deferred_probe_work_func

The stack trace is a bit misleading as dw_pcie_host_deinit() doesn't

directly call pci_bus_release_domain_nr(). The issue turns out to be in

pci_remove_root_bus() which first calls pci_remove_bus() which frees the

struct pci_bus when its struct device is released. Then

pci_bus_release_domain_nr() is called and accesses the freed struct

pci_bus. Reordering these fixes the issue.