| Message ID | 20230329123835.2724518-1-robh@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI: Fix use-after-free in pci_bus_release_domain_nr() | expand |
On 3/29/23 5:38 AM, Rob Herring wrote: > 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: > > [ 19.285870] ================================================================== > [ 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 > [ 19.309764] really_probe+0xb8/0x298 > [ 19.309777] __driver_probe_device+0x78/0xd8 > [ 19.309788] driver_probe_device+0x38/0x120 > [ 19.309799] __device_attach_driver+0x94/0xe0 > [ 19.309812] bus_for_each_drv+0x70/0xc8 > [ 19.309822] __device_attach+0xfc/0x188 > [ 19.309833] device_initial_probe+0x10/0x18 > [ 19.309844] bus_probe_device+0x94/0xa0 > [ 19.309854] deferred_probe_work_func+0x80/0xb8 > [ 19.309864] process_one_work+0x1e0/0x348 > [ 19.309882] worker_thread+0x48/0x410 > [ 19.309891] kthread+0xf4/0x110 > [ 19.309904] ret_from_fork+0x10/0x20 > > [ 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 > [ 19.311653] really_probe+0xb8/0x298 > [ 19.311663] __driver_probe_device+0x78/0xd8 > [ 19.311672] driver_probe_device+0x38/0x120 > [ 19.311682] __device_attach_driver+0x94/0xe0 > [ 19.311694] bus_for_each_drv+0x70/0xc8 > [ 19.311702] __device_attach+0xfc/0x188 > [ 19.311713] device_initial_probe+0x10/0x18 > [ 19.311724] bus_probe_device+0x94/0xa0 > [ 19.311733] deferred_probe_work_func+0x80/0xb8 > [ 19.311743] process_one_work+0x1e0/0x348 > [ 19.311753] worker_thread+0x48/0x410 > [ 19.311763] kthread+0xf4/0x110 > [ 19.311771] ret_from_fork+0x10/0x20 > > [ 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 > [ 19.311906] really_probe+0xb8/0x298 > [ 19.311916] __driver_probe_device+0x78/0xd8 > [ 19.311926] driver_probe_device+0x38/0x120 > [ 19.311936] __device_attach_driver+0x94/0xe0 > [ 19.311947] bus_for_each_drv+0x70/0xc8 > [ 19.311956] __device_attach+0xfc/0x188 > [ 19.311966] device_initial_probe+0x10/0x18 > [ 19.311976] bus_probe_device+0x94/0xa0 > [ 19.311985] deferred_probe_work_func+0x80/0xb8 > [ 19.311995] process_one_work+0x1e0/0x348 > [ 19.312005] worker_thread+0x48/0x410 > [ 19.312014] kthread+0xf4/0x110 > [ 19.312022] ret_from_fork+0x10/0x20 > > [ 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 > [ 19.331919] ================================================================== > > 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. Since time log is not useful, remove it and just add stack trace. Change looks good to me. But I am not sure whether pci_remove_bus() directly frees struct pci_bus or just removes the bus resources? > > Fixes: c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()") > Reported-by: Jon Hunter <jonathanh@nvidia.com> > Tested-by: Jon Hunter <jonathanh@nvidia.com> > Cc: Pali Rohár <pali@kernel.org> > Signed-off-by: Rob Herring <robh@kernel.org> > --- > drivers/pci/remove.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c > index 0145aef1b930..22d39e12b236 100644 > --- a/drivers/pci/remove.c > +++ b/drivers/pci/remove.c > @@ -157,8 +157,6 @@ void pci_remove_root_bus(struct pci_bus *bus) > list_for_each_entry_safe(child, tmp, > &bus->devices, bus_list) > pci_remove_bus_device(child); > - pci_remove_bus(bus); > - host_bridge->bus = NULL; > > #ifdef CONFIG_PCI_DOMAINS_GENERIC > /* Release domain_nr if it was dynamically allocated */ > @@ -166,6 +164,9 @@ void pci_remove_root_bus(struct pci_bus *bus) > pci_bus_release_domain_nr(bus, host_bridge->dev.parent); > #endif > > + pci_remove_bus(bus); > + host_bridge->bus = NULL; > + > /* remove the host bridge */ > device_del(&host_bridge->dev); > }
On Wed, Mar 29, 2023 at 10:13 AM Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com> wrote: > > > > On 3/29/23 5:38 AM, Rob Herring wrote: > > 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: > > > > [ 19.285870] ================================================================== > > [ 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 > > [ 19.309764] really_probe+0xb8/0x298 > > [ 19.309777] __driver_probe_device+0x78/0xd8 > > [ 19.309788] driver_probe_device+0x38/0x120 > > [ 19.309799] __device_attach_driver+0x94/0xe0 > > [ 19.309812] bus_for_each_drv+0x70/0xc8 > > [ 19.309822] __device_attach+0xfc/0x188 > > [ 19.309833] device_initial_probe+0x10/0x18 > > [ 19.309844] bus_probe_device+0x94/0xa0 > > [ 19.309854] deferred_probe_work_func+0x80/0xb8 > > [ 19.309864] process_one_work+0x1e0/0x348 > > [ 19.309882] worker_thread+0x48/0x410 > > [ 19.309891] kthread+0xf4/0x110 > > [ 19.309904] ret_from_fork+0x10/0x20 > > > > [ 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 > > [ 19.311653] really_probe+0xb8/0x298 > > [ 19.311663] __driver_probe_device+0x78/0xd8 > > [ 19.311672] driver_probe_device+0x38/0x120 > > [ 19.311682] __device_attach_driver+0x94/0xe0 > > [ 19.311694] bus_for_each_drv+0x70/0xc8 > > [ 19.311702] __device_attach+0xfc/0x188 > > [ 19.311713] device_initial_probe+0x10/0x18 > > [ 19.311724] bus_probe_device+0x94/0xa0 > > [ 19.311733] deferred_probe_work_func+0x80/0xb8 > > [ 19.311743] process_one_work+0x1e0/0x348 > > [ 19.311753] worker_thread+0x48/0x410 > > [ 19.311763] kthread+0xf4/0x110 > > [ 19.311771] ret_from_fork+0x10/0x20 > > > > [ 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 > > [ 19.311906] really_probe+0xb8/0x298 > > [ 19.311916] __driver_probe_device+0x78/0xd8 > > [ 19.311926] driver_probe_device+0x38/0x120 > > [ 19.311936] __device_attach_driver+0x94/0xe0 > > [ 19.311947] bus_for_each_drv+0x70/0xc8 > > [ 19.311956] __device_attach+0xfc/0x188 > > [ 19.311966] device_initial_probe+0x10/0x18 > > [ 19.311976] bus_probe_device+0x94/0xa0 > > [ 19.311985] deferred_probe_work_func+0x80/0xb8 > > [ 19.311995] process_one_work+0x1e0/0x348 > > [ 19.312005] worker_thread+0x48/0x410 > > [ 19.312014] kthread+0xf4/0x110 > > [ 19.312022] ret_from_fork+0x10/0x20 > > > > [ 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 > > [ 19.331919] ================================================================== > > > > 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. > > Since time log is not useful, remove it and just add stack trace. Actually, it was useful. It told me that the use-after-free happened pretty much right after the free. Bjorn likes to edit commit messages so I'll leave it up to him to leave or change. > Change looks good to me. But I am not sure whether pci_remove_bus() > directly frees struct pci_bus or just removes the bus resources? struct pci_bus embeds a struct device. The struct device is put which causes the free of the struct pci_bus. So indirect in that the refcounting triggers the free, but direct in that pci_remove_bus() causes it. Rob
On 3/29/23 8:59 AM, Rob Herring wrote: > On Wed, Mar 29, 2023 at 10:13 AM Sathyanarayanan Kuppuswamy > <sathyanarayanan.kuppuswamy@linux.intel.com> wrote: >> >> >> >> On 3/29/23 5:38 AM, Rob Herring wrote: >>> 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: >>> >>> [ 19.285870] ================================================================== >>> [ 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 >>> [ 19.309764] really_probe+0xb8/0x298 >>> [ 19.309777] __driver_probe_device+0x78/0xd8 >>> [ 19.309788] driver_probe_device+0x38/0x120 >>> [ 19.309799] __device_attach_driver+0x94/0xe0 >>> [ 19.309812] bus_for_each_drv+0x70/0xc8 >>> [ 19.309822] __device_attach+0xfc/0x188 >>> [ 19.309833] device_initial_probe+0x10/0x18 >>> [ 19.309844] bus_probe_device+0x94/0xa0 >>> [ 19.309854] deferred_probe_work_func+0x80/0xb8 >>> [ 19.309864] process_one_work+0x1e0/0x348 >>> [ 19.309882] worker_thread+0x48/0x410 >>> [ 19.309891] kthread+0xf4/0x110 >>> [ 19.309904] ret_from_fork+0x10/0x20 >>> >>> [ 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 >>> [ 19.311653] really_probe+0xb8/0x298 >>> [ 19.311663] __driver_probe_device+0x78/0xd8 >>> [ 19.311672] driver_probe_device+0x38/0x120 >>> [ 19.311682] __device_attach_driver+0x94/0xe0 >>> [ 19.311694] bus_for_each_drv+0x70/0xc8 >>> [ 19.311702] __device_attach+0xfc/0x188 >>> [ 19.311713] device_initial_probe+0x10/0x18 >>> [ 19.311724] bus_probe_device+0x94/0xa0 >>> [ 19.311733] deferred_probe_work_func+0x80/0xb8 >>> [ 19.311743] process_one_work+0x1e0/0x348 >>> [ 19.311753] worker_thread+0x48/0x410 >>> [ 19.311763] kthread+0xf4/0x110 >>> [ 19.311771] ret_from_fork+0x10/0x20 >>> >>> [ 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 >>> [ 19.311906] really_probe+0xb8/0x298 >>> [ 19.311916] __driver_probe_device+0x78/0xd8 >>> [ 19.311926] driver_probe_device+0x38/0x120 >>> [ 19.311936] __device_attach_driver+0x94/0xe0 >>> [ 19.311947] bus_for_each_drv+0x70/0xc8 >>> [ 19.311956] __device_attach+0xfc/0x188 >>> [ 19.311966] device_initial_probe+0x10/0x18 >>> [ 19.311976] bus_probe_device+0x94/0xa0 >>> [ 19.311985] deferred_probe_work_func+0x80/0xb8 >>> [ 19.311995] process_one_work+0x1e0/0x348 >>> [ 19.312005] worker_thread+0x48/0x410 >>> [ 19.312014] kthread+0xf4/0x110 >>> [ 19.312022] ret_from_fork+0x10/0x20 >>> >>> [ 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 >>> [ 19.331919] ================================================================== >>> >>> 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. >> >> Since time log is not useful, remove it and just add stack trace. > > Actually, it was useful. It told me that the use-after-free happened > pretty much right after the free. > > Bjorn likes to edit commit messages so I'll leave it up to him to > leave or change. > >> Change looks good to me. But I am not sure whether pci_remove_bus() >> directly frees struct pci_bus or just removes the bus resources? > > struct pci_bus embeds a struct device. The struct device is put which > causes the free of the struct pci_bus. So indirect in that the > refcounting triggers the free, but direct in that pci_remove_bus() > causes it. Got it. Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> > > Rob
On Wed, Mar 29, 2023 at 07:38:35AM -0500, Rob Herring wrote: > 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: > > [ 19.285870] ================================================================== > [ 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 > [ 19.309764] really_probe+0xb8/0x298 > [ 19.309777] __driver_probe_device+0x78/0xd8 > [ 19.309788] driver_probe_device+0x38/0x120 > [ 19.309799] __device_attach_driver+0x94/0xe0 > [ 19.309812] bus_for_each_drv+0x70/0xc8 > [ 19.309822] __device_attach+0xfc/0x188 > [ 19.309833] device_initial_probe+0x10/0x18 > [ 19.309844] bus_probe_device+0x94/0xa0 > [ 19.309854] deferred_probe_work_func+0x80/0xb8 > [ 19.309864] process_one_work+0x1e0/0x348 > [ 19.309882] worker_thread+0x48/0x410 > [ 19.309891] kthread+0xf4/0x110 > [ 19.309904] ret_from_fork+0x10/0x20 > > [ 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 > [ 19.311653] really_probe+0xb8/0x298 > [ 19.311663] __driver_probe_device+0x78/0xd8 > [ 19.311672] driver_probe_device+0x38/0x120 > [ 19.311682] __device_attach_driver+0x94/0xe0 > [ 19.311694] bus_for_each_drv+0x70/0xc8 > [ 19.311702] __device_attach+0xfc/0x188 > [ 19.311713] device_initial_probe+0x10/0x18 > [ 19.311724] bus_probe_device+0x94/0xa0 > [ 19.311733] deferred_probe_work_func+0x80/0xb8 > [ 19.311743] process_one_work+0x1e0/0x348 > [ 19.311753] worker_thread+0x48/0x410 > [ 19.311763] kthread+0xf4/0x110 > [ 19.311771] ret_from_fork+0x10/0x20 > > [ 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 > [ 19.311906] really_probe+0xb8/0x298 > [ 19.311916] __driver_probe_device+0x78/0xd8 > [ 19.311926] driver_probe_device+0x38/0x120 > [ 19.311936] __device_attach_driver+0x94/0xe0 > [ 19.311947] bus_for_each_drv+0x70/0xc8 > [ 19.311956] __device_attach+0xfc/0x188 > [ 19.311966] device_initial_probe+0x10/0x18 > [ 19.311976] bus_probe_device+0x94/0xa0 > [ 19.311985] deferred_probe_work_func+0x80/0xb8 > [ 19.311995] process_one_work+0x1e0/0x348 > [ 19.312005] worker_thread+0x48/0x410 > [ 19.312014] kthread+0xf4/0x110 > [ 19.312022] ret_from_fork+0x10/0x20 > > [ 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 > [ 19.331919] ================================================================== > > 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. > > Fixes: c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()") > Reported-by: Jon Hunter <jonathanh@nvidia.com> > Tested-by: Jon Hunter <jonathanh@nvidia.com> > Cc: Pali Rohár <pali@kernel.org> > Signed-off-by: Rob Herring <robh@kernel.org> Applied to for-linus for v6.3, thanks! I also added a stable tag since c14f7ccc9f5d appeared in v6.2. > --- > drivers/pci/remove.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c > index 0145aef1b930..22d39e12b236 100644 > --- a/drivers/pci/remove.c > +++ b/drivers/pci/remove.c > @@ -157,8 +157,6 @@ void pci_remove_root_bus(struct pci_bus *bus) > list_for_each_entry_safe(child, tmp, > &bus->devices, bus_list) > pci_remove_bus_device(child); > - pci_remove_bus(bus); > - host_bridge->bus = NULL; > > #ifdef CONFIG_PCI_DOMAINS_GENERIC > /* Release domain_nr if it was dynamically allocated */ > @@ -166,6 +164,9 @@ void pci_remove_root_bus(struct pci_bus *bus) > pci_bus_release_domain_nr(bus, host_bridge->dev.parent); > #endif > > + pci_remove_bus(bus); > + host_bridge->bus = NULL; > + > /* remove the host bridge */ > device_del(&host_bridge->dev); > } > -- > 2.39.2 >
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index 0145aef1b930..22d39e12b236 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -157,8 +157,6 @@ void pci_remove_root_bus(struct pci_bus *bus) list_for_each_entry_safe(child, tmp, &bus->devices, bus_list) pci_remove_bus_device(child); - pci_remove_bus(bus); - host_bridge->bus = NULL; #ifdef CONFIG_PCI_DOMAINS_GENERIC /* Release domain_nr if it was dynamically allocated */ @@ -166,6 +164,9 @@ void pci_remove_root_bus(struct pci_bus *bus) pci_bus_release_domain_nr(bus, host_bridge->dev.parent); #endif + pci_remove_bus(bus); + host_bridge->bus = NULL; + /* remove the host bridge */ device_del(&host_bridge->dev); }
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: [ 19.285870] ================================================================== [ 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 [ 19.309764] really_probe+0xb8/0x298 [ 19.309777] __driver_probe_device+0x78/0xd8 [ 19.309788] driver_probe_device+0x38/0x120 [ 19.309799] __device_attach_driver+0x94/0xe0 [ 19.309812] bus_for_each_drv+0x70/0xc8 [ 19.309822] __device_attach+0xfc/0x188 [ 19.309833] device_initial_probe+0x10/0x18 [ 19.309844] bus_probe_device+0x94/0xa0 [ 19.309854] deferred_probe_work_func+0x80/0xb8 [ 19.309864] process_one_work+0x1e0/0x348 [ 19.309882] worker_thread+0x48/0x410 [ 19.309891] kthread+0xf4/0x110 [ 19.309904] ret_from_fork+0x10/0x20 [ 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 [ 19.311653] really_probe+0xb8/0x298 [ 19.311663] __driver_probe_device+0x78/0xd8 [ 19.311672] driver_probe_device+0x38/0x120 [ 19.311682] __device_attach_driver+0x94/0xe0 [ 19.311694] bus_for_each_drv+0x70/0xc8 [ 19.311702] __device_attach+0xfc/0x188 [ 19.311713] device_initial_probe+0x10/0x18 [ 19.311724] bus_probe_device+0x94/0xa0 [ 19.311733] deferred_probe_work_func+0x80/0xb8 [ 19.311743] process_one_work+0x1e0/0x348 [ 19.311753] worker_thread+0x48/0x410 [ 19.311763] kthread+0xf4/0x110 [ 19.311771] ret_from_fork+0x10/0x20 [ 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 [ 19.311906] really_probe+0xb8/0x298 [ 19.311916] __driver_probe_device+0x78/0xd8 [ 19.311926] driver_probe_device+0x38/0x120 [ 19.311936] __device_attach_driver+0x94/0xe0 [ 19.311947] bus_for_each_drv+0x70/0xc8 [ 19.311956] __device_attach+0xfc/0x188 [ 19.311966] device_initial_probe+0x10/0x18 [ 19.311976] bus_probe_device+0x94/0xa0 [ 19.311985] deferred_probe_work_func+0x80/0xb8 [ 19.311995] process_one_work+0x1e0/0x348 [ 19.312005] worker_thread+0x48/0x410 [ 19.312014] kthread+0xf4/0x110 [ 19.312022] ret_from_fork+0x10/0x20 [ 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 [ 19.331919] ================================================================== 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. Fixes: c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()") Reported-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Cc: Pali Rohár <pali@kernel.org> Signed-off-by: Rob Herring <robh@kernel.org> --- drivers/pci/remove.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)