CVE-2023-52910 iommu/iova: Fix alloc iova overflows issue

2024-08-2106:10:51

Linux

www.cve.org

linux kernel

iommu

iova

alloc iova

overflow issue

vulnerability

fix

security

cve-2023-52910

EPSS

Percentile

5.1%

JSON

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

iommu/iova: Fix alloc iova overflows issue

In __alloc_and_insert_iova_range, there is an issue that retry_pfn
overflows. The value of iovad->anchor.pfn_hi is ~0UL, then when
iovad->cached_node is iovad->anchor, curr_iova->pfn_hi + 1 will
overflow. As a result, if the retry logic is executed, low_pfn is
updated to 0, and then new_pfn < low_pfn returns false to make the
allocation successful.

This issue occurs in the following two situations:

The first iova size exceeds the domain size. When initializing
iova domain, iovad->cached_node is assigned as iovad->anchor. For
example, the iova domain size is 10M, start_pfn is 0x1_F000_0000,
and the iova size allocated for the first time is 11M. The
following is the log information, new->pfn_lo is smaller than
iovad->cached_node.

Example log as follows:
[ 223.798112][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range
start_pfn:0x1f0000,retry_pfn:0x0,size:0xb00,limit_pfn:0x1f0a00
[ 223.799590][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range
success start_pfn:0x1f0000,new->pfn_lo:0x1efe00,new->pfn_hi:0x1f08ff

The node with the largest iova->pfn_lo value in the iova domain
is deleted, iovad->cached_node will be updated to iovad->anchor,
and then the alloc iova size exceeds the maximum iova size that can
be allocated in the domain.

After judging that retry_pfn is less than limit_pfn, call retry_pfn+1
to fix the overflow issue.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/iommu/iova.c"
    ],
    "versions": [
      {
        "version": "4e89dce72521",
        "lessThan": "c929a230c844",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "4e89dce72521",
        "lessThan": "61cbf790e732",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "4e89dce72521",
        "lessThan": "dcdb3ba7e2a8",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/iommu/iova.c"
    ],
    "versions": [
      {
        "version": "5.11",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.11",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.89",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.7",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.2",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]