From 9ac8545199a1b711f5643f535b82981faa0b4bf1 Mon Sep 17 00:00:00 2001 From: Qian Cai Date: Fri, 3 Jul 2020 20:10:03 -0400 Subject: [PATCH] iommu: Fix use-after-free in iommu_release_device In pci_disable_sriov(), i.e., # echo 0 > /sys/class/net/enp11s0f1np1/device/sriov_numvfs iommu_release_device iommu_group_remove_device arm_smmu_domain_free kfree(smmu_domain) Later, iommu_release_device arm_smmu_release_device arm_smmu_detach_dev spin_lock_irqsave(&smmu_domain->devices_lock, would trigger an use-after-free. Fixed it by call arm_smmu_release_device() first before iommu_group_remove_device(). BUG: KASAN: use-after-free in __lock_acquire+0x3458/0x4440 __lock_acquire at kernel/locking/lockdep.c:4250 Read of size 8 at addr ffff0089df1a6f68 by task bash/3356 CPU: 5 PID: 3356 Comm: bash Not tainted 5.8.0-rc3-next-20200630 #2 Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019 Call trace: dump_backtrace+0x0/0x398 show_stack+0x14/0x20 dump_stack+0x140/0x1b8 print_address_description.isra.12+0x54/0x4a8 kasan_report+0x134/0x1b8 __asan_report_load8_noabort+0x2c/0x50 __lock_acquire+0x3458/0x4440 lock_acquire+0x204/0xf10 _raw_spin_lock_irqsave+0xf8/0x180 arm_smmu_detach_dev+0xd8/0x4a0 arm_smmu_detach_dev at drivers/iommu/arm-smmu-v3.c:2776 arm_smmu_release_device+0xb4/0x1c8 arm_smmu_disable_pasid at drivers/iommu/arm-smmu-v3.c:2754 (inlined by) arm_smmu_release_device at drivers/iommu/arm-smmu-v3.c:3000 iommu_release_device+0xc0/0x178 iommu_release_device at drivers/iommu/iommu.c:302 iommu_bus_notifier+0x118/0x160 notifier_call_chain+0xa4/0x128 __blocking_notifier_call_chain+0x70/0xa8 blocking_notifier_call_chain+0x14/0x20 device_del+0x618/0xa00 pci_remove_bus_device+0x108/0x2d8 pci_stop_and_remove_bus_device+0x1c/0x28 pci_iov_remove_virtfn+0x228/0x368 sriov_disable+0x8c/0x348 pci_disable_sriov+0x5c/0x70 mlx5_core_sriov_configure+0xd8/0x260 [mlx5_core] sriov_numvfs_store+0x240/0x318 dev_attr_store+0x38/0x68 sysfs_kf_write+0xdc/0x128 kernfs_fop_write+0x23c/0x448 __vfs_write+0x54/0xe8 vfs_write+0x124/0x3f0 ksys_write+0xe8/0x1b8 __arm64_sys_write+0x68/0x98 do_el0_svc+0x124/0x220 el0_sync_handler+0x260/0x408 el0_sync+0x140/0x180 Allocated by task 3356: save_stack+0x24/0x50 __kasan_kmalloc.isra.13+0xc4/0xe0 kasan_kmalloc+0xc/0x18 kmem_cache_alloc_trace+0x1ec/0x318 arm_smmu_domain_alloc+0x54/0x148 iommu_group_alloc_default_domain+0xc0/0x440 iommu_probe_device+0x1c0/0x308 iort_iommu_configure+0x434/0x518 acpi_dma_configure+0xf0/0x128 pci_dma_configure+0x114/0x160 really_probe+0x124/0x6d8 driver_probe_device+0xc4/0x180 __device_attach_driver+0x184/0x1e8 bus_for_each_drv+0x114/0x1a0 __device_attach+0x19c/0x2a8 device_attach+0x10/0x18 pci_bus_add_device+0x70/0xf8 pci_iov_add_virtfn+0x7b4/0xb40 sriov_enable+0x5c8/0xc30 pci_enable_sriov+0x64/0x80 mlx5_core_sriov_configure+0x58/0x260 [mlx5_core] sriov_numvfs_store+0x1c0/0x318 dev_attr_store+0x38/0x68 sysfs_kf_write+0xdc/0x128 kernfs_fop_write+0x23c/0x448 __vfs_write+0x54/0xe8 vfs_write+0x124/0x3f0 ksys_write+0xe8/0x1b8 __arm64_sys_write+0x68/0x98 do_el0_svc+0x124/0x220 el0_sync_handler+0x260/0x408 el0_sync+0x140/0x180 Freed by task 3356: save_stack+0x24/0x50 __kasan_slab_free+0x124/0x198 kasan_slab_free+0x10/0x18 slab_free_freelist_hook+0x110/0x298 kfree+0x128/0x668 arm_smmu_domain_free+0xf4/0x1a0 iommu_group_release+0xec/0x160 kobject_put+0xf4/0x238 kobject_del+0x110/0x190 kobject_put+0x1e4/0x238 iommu_group_remove_device+0x394/0x938 iommu_release_device+0x9c/0x178 iommu_release_device at drivers/iommu/iommu.c:300 iommu_bus_notifier+0x118/0x160 notifier_call_chain+0xa4/0x128 __blocking_notifier_call_chain+0x70/0xa8 blocking_notifier_call_chain+0x14/0x20 device_del+0x618/0xa00 pci_remove_bus_device+0x108/0x2d8 pci_stop_and_remove_bus_device+0x1c/0x28 pci_iov_remove_virtfn+0x228/0x368 sriov_disable+0x8c/0x348 pci_disable_sriov+0x5c/0x70 mlx5_core_sriov_configure+0xd8/0x260 [mlx5_core] sriov_numvfs_store+0x240/0x318 dev_attr_store+0x38/0x68 sysfs_kf_write+0xdc/0x128 kernfs_fop_write+0x23c/0x448 __vfs_write+0x54/0xe8 vfs_write+0x124/0x3f0 ksys_write+0xe8/0x1b8 __arm64_sys_write+0x68/0x98 do_el0_svc+0x124/0x220 el0_sync_handler+0x260/0x408 el0_sync+0x140/0x180 The buggy address belongs to the object at ffff0089df1a6e00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 360 bytes inside of 512-byte region [ffff0089df1a6e00, ffff0089df1a7000) The buggy address belongs to the page: page:ffffffe02257c680 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0089df1a1400 flags: 0x7ffff800000200(slab) raw: 007ffff800000200 ffffffe02246b8c8 ffffffe02257ff88 ffff000000320680 raw: ffff0089df1a1400 00000000002a000e 00000001ffffffff ffff0089df1a5001 page dumped because: kasan: bad access detected page->mem_cgroup:ffff0089df1a5001 Memory state around the buggy address: ffff0089df1a6e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0089df1a6e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0089df1a6f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0089df1a6f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0089df1a7000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc Fixes: a6a4c7e2c5b8 ("iommu: Add probe_device() and release_device() call-backs") Signed-off-by: Qian Cai Link: https://lore.kernel.org/r/20200704001003.2303-1-cai@lca.pw Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index d43120eb1dc5..b6858adc4f17 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -295,10 +295,10 @@ void iommu_release_device(struct device *dev) return; iommu_device_unlink(dev->iommu->iommu_dev, dev); - iommu_group_remove_device(dev); ops->release_device(dev); + iommu_group_remove_device(dev); module_put(ops->owner); dev_iommu_free(dev); }