CVE-2024-26713 powerpc/pseries/iommu: Fix iommu initialisation during DLPAR add

2024-04-0314:55:14

Linux

www.cve.org

vulnerability resolved

null pointer dereference

kernel oops

pci device

dlpar add

iommu initialization

powerpc

pseries

kernel patch

system boot

dlpar fix

6.6 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.7%

JSON

In the Linux kernel, the following vulnerability has been resolved:

powerpc/pseries/iommu: Fix iommu initialisation during DLPAR add

When a PCI device is dynamically added, the kernel oopses with a NULL
pointer dereference:

BUG: Kernel NULL pointer dereference on read at 0x00000030
Faulting instruction address: 0xc0000000006bbe5c
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: rpadlpar_io rpaphp rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs xsk_diag bonding nft_compat nf_tables nfnetlink rfkill binfmt_misc dm_multipath rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_umad ib_iser libiscsi scsi_transport_iscsi ib_ipoib rdma_cm iw_cm ib_cm mlx5_ib ib_uverbs ib_core pseries_rng drm drm_panel_orientation_quirks xfs libcrc32c mlx5_core mlxfw sd_mod t10_pi sg tls ibmvscsi ibmveth scsi_transport_srp vmx_crypto pseries_wdt psample dm_mirror dm_region_hash dm_log dm_mod fuse
CPU: 17 PID: 2685 Comm: drmgr Not tainted 6.7.0-203405+ #66
Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries
NIP: c0000000006bbe5c LR: c000000000a13e68 CTR: c0000000000579f8
REGS: c00000009924f240 TRAP: 0300 Not tainted (6.7.0-203405+)
MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 24002220 XER: 20040006
CFAR: c000000000a13e64 DAR: 0000000000000030 DSISR: 40000000 IRQMASK: 0
…
NIP sysfs_add_link_to_group+0x34/0x94
LR iommu_device_link+0x5c/0x118
Call Trace:
iommu_init_device+0x26c/0x318 (unreliable)
iommu_device_link+0x5c/0x118
iommu_init_device+0xa8/0x318
iommu_probe_device+0xc0/0x134
iommu_bus_notifier+0x44/0x104
notifier_call_chain+0xb8/0x19c
blocking_notifier_call_chain+0x64/0x98
bus_notify+0x50/0x7c
device_add+0x640/0x918
pci_device_add+0x23c/0x298
of_create_pci_dev+0x400/0x884
of_scan_pci_dev+0x124/0x1b0
__of_scan_bus+0x78/0x18c
pcibios_scan_phb+0x2a4/0x3b0
init_phb_dynamic+0xb8/0x110
dlpar_add_slot+0x170/0x3b8 [rpadlpar_io]
add_slot_store.part.0+0xb4/0x130 [rpadlpar_io]
kobj_attr_store+0x2c/0x48
sysfs_kf_write+0x64/0x78
kernfs_fop_write_iter+0x1b0/0x290
vfs_write+0x350/0x4a0
ksys_write+0x84/0x140
system_call_exception+0x124/0x330
system_call_vectored_common+0x15c/0x2ec

Commit a940904443e4 (“powerpc/iommu: Add iommu_ops to report capabilities
and allow blocking domains”) broke DLPAR add of PCI devices.

The above added iommu_device structure to pci_controller. During
system boot, PCI devices are discovered and this newly added iommu_device
structure is initialized by a call to iommu_device_register().

During DLPAR add of a PCI device, a new pci_controller structure is
allocated but there are no calls made to iommu_device_register()
interface.

Fix is to register the iommu device during DLPAR add as well.

[mpe: Trim oops and tweak some change log wording]

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/powerpc/include/asm/ppc-pci.h",
      "arch/powerpc/kernel/iommu.c",
      "arch/powerpc/platforms/pseries/pci_dlpar.c"
    ],
    "versions": [
      {
        "version": "a940904443e4",
        "lessThan": "9978d5b744e0",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "a940904443e4",
        "lessThan": "d4f762d6403f",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "a940904443e4",
        "lessThan": "ed8b94f6e0ac",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/powerpc/include/asm/ppc-pci.h",
      "arch/powerpc/kernel/iommu.c",
      "arch/powerpc/platforms/pseries/pci_dlpar.c"
    ],
    "versions": [
      {
        "version": "6.4",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "6.4",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.18",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.7.6",
        "lessThanOrEqual": "6.7.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]