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authorDaniel Drake <drake@endlessm.com>2020-03-12 14:09:55 +0800
committerJoerg Roedel <jroedel@suse.de>2020-03-14 09:38:39 +0100
commitda72a379b2ec0bad3eb265787f7008bead0b040c (patch)
tree51266964e9ceec405459006076261d05cb8088f7 /drivers/iommu
parentb0bb0c22c4db623f2e7b1a471596fbf1c22c6dc5 (diff)
downloadlinux-da72a379b2ec0bad3eb265787f7008bead0b040c.tar.bz2
iommu/vt-d: Ignore devices with out-of-spec domain number
VMD subdevices are created with a PCI domain ID of 0x10000 or higher. These subdevices are also handled like all other PCI devices by dmar_pci_bus_notifier(). However, when dmar_alloc_pci_notify_info() take records of such devices, it will truncate the domain ID to a u16 value (in info->seg). The device at (e.g.) 10000:00:02.0 is then treated by the DMAR code as if it is 0000:00:02.0. In the unlucky event that a real device also exists at 0000:00:02.0 and also has a device-specific entry in the DMAR table, dmar_insert_dev_scope() will crash on:   BUG_ON(i >= devices_cnt); That's basically a sanity check that only one PCI device matches a single DMAR entry; in this case we seem to have two matching devices. Fix this by ignoring devices that have a domain number higher than what can be looked up in the DMAR table. This problem was carefully diagnosed by Jian-Hong Pan. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Daniel Drake <drake@endlessm.com> Fixes: 59ce0515cdaf3 ("iommu/vt-d: Update DRHD/RMRR/ATSR device scope caches when PCI hotplug happens") Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/dmar.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index c7b1461e8d0a..f77dae7ba7d4 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -28,6 +28,7 @@
#include <linux/slab.h>
#include <linux/iommu.h>
#include <linux/numa.h>
+#include <linux/limits.h>
#include <asm/irq_remapping.h>
#include <asm/iommu_table.h>
@@ -128,6 +129,13 @@ dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event)
BUG_ON(dev->is_virtfn);
+ /*
+ * Ignore devices that have a domain number higher than what can
+ * be looked up in DMAR, e.g. VMD subdevices with domain 0x10000
+ */
+ if (pci_domain_nr(dev->bus) > U16_MAX)
+ return NULL;
+
/* Only generate path[] for device addition event */
if (event == BUS_NOTIFY_ADD_DEVICE)
for (tmp = dev; tmp; tmp = tmp->bus->self)