[ Upstream commit cffaaf0c816238c45cd2d06913476c83eb50f682 ]
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 Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- 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 c0d1c4db5794..38d0128b8135 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -144,7 +144,7 @@ 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 {