mainline inclusion
from mainline-5.0
commit cffaaf0c816238c45cd2d06913476c83eb50f682
category: bugfix
bugzilla: 11110
CVE: NA

-------------------------------------------------
Commit 57384592 ("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: 57384592 ("iommu/vt-d: Store bus information in RMRR PCI device path")
Signed-off-by: NJulia Cartwright <julia@ni.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>
(cherry picked from commit cffaaf0c816238c45cd2d06913476c83eb50f682)
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>