Commit 57384592c4 ("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: 57384592c4 ("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>
cffaaf0c81