Messages in this thread Patch in this message | | | From | Julia Cartwright <> | Subject | [PATCH] iommu/dmar: fix buffer overflow during PCI bus notification | Date | Wed, 20 Feb 2019 16:46:31 +0000 |
| |
Commit 57384592c433 ("iommu/vt-d: Store bus information in RMRR PCI device path") changed the type of the path data, however, the change in path type was not reflected in size calculations. Update to use the correct type and prevent a buffer overflow.
This bug manifests in systems with deep PCI hierarchies, and can lead to an overflow of the static allocated buffer (dmar_pci_notify_info_buf), or can lead to overflow of slab-allocated data.
BUG: KASAN: global-out-of-bounds in dmar_alloc_pci_notify_info+0x1d5/0x2e0 Write of size 1 at addr ffffffff90445d80 by task swapper/0/1 CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 4.14.87-rt49-02406-gd0a0e96 #1 Call Trace: ? dump_stack+0x46/0x59 ? print_address_description+0x1df/0x290 ? dmar_alloc_pci_notify_info+0x1d5/0x2e0 ? kasan_report+0x256/0x340 ? dmar_alloc_pci_notify_info+0x1d5/0x2e0 ? e820__memblock_setup+0xb0/0xb0 ? dmar_dev_scope_init+0x424/0x48f ? __down_write_common+0x1ec/0x230 ? dmar_dev_scope_init+0x48f/0x48f ? dmar_free_unused_resources+0x109/0x109 ? cpumask_next+0x16/0x20 ? __kmem_cache_create+0x392/0x430 ? kmem_cache_create+0x135/0x2f0 ? e820__memblock_setup+0xb0/0xb0 ? intel_iommu_init+0x170/0x1848 ? _raw_spin_unlock_irqrestore+0x32/0x60 ? migrate_enable+0x27a/0x5b0 ? sched_setattr+0x20/0x20 ? migrate_disable+0x1fc/0x380 ? task_rq_lock+0x170/0x170 ? try_to_run_init_process+0x40/0x40 ? locks_remove_file+0x85/0x2f0 ? dev_prepare_static_identity_mapping+0x78/0x78 ? rt_spin_unlock+0x39/0x50 ? lockref_put_or_lock+0x2a/0x40 ? dput+0x128/0x2f0 ? __rcu_read_unlock+0x66/0x80 ? __fput+0x250/0x300 ? __rcu_read_lock+0x1b/0x30 ? mntput_no_expire+0x38/0x290 ? e820__memblock_setup+0xb0/0xb0 ? pci_iommu_init+0x25/0x63 ? pci_iommu_init+0x25/0x63 ? do_one_initcall+0x7e/0x1c0 ? initcall_blacklisted+0x120/0x120 ? kernel_init_freeable+0x27b/0x307 ? rest_init+0xd0/0xd0 ? kernel_init+0xf/0x120 ? rest_init+0xd0/0xd0 ? ret_from_fork+0x1f/0x40 The buggy address belongs to the variable: dmar_pci_notify_info_buf+0x40/0x60
Fixes: 57384592c433 ("iommu/vt-d: Store bus information in RMRR PCI device path") Signed-off-by: Julia Cartwright <julia@ni.com> --- drivers/iommu/dmar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index 6b7df25e1488..9c49300e9fb7 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -145,7 +145,7 @@ dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event) for (tmp = dev; tmp; tmp = tmp->bus->self) level++; - size = sizeof(*info) + level * sizeof(struct acpi_dmar_pci_path); + size = sizeof(*info) + level * sizeof(info->path[0]); if (size <= sizeof(dmar_pci_notify_info_buf)) { info = (struct dmar_pci_notify_info *)dmar_pci_notify_info_buf; } else { -- 2.20.1
| |