CVE-2022-50738 (GCVE-0-2022-50738)

Vulnerability from cvelistv5 – Published: 2025-12-24 13:05 – Updated: 2025-12-24 13:05
VLAI?
Title
vhost-vdpa: fix an iotlb memory leak
Summary
In the Linux kernel, the following vulnerability has been resolved: vhost-vdpa: fix an iotlb memory leak Before commit 3d5698793897 ("vhost-vdpa: introduce asid based IOTLB") we called vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1) during release to free all the resources allocated when processing user IOTLB messages through vhost_vdpa_process_iotlb_update(). That commit changed the handling of IOTLB a bit, and we accidentally removed some code called during the release. We partially fixed this with commit 037d4305569a ("vhost-vdpa: call vhost_vdpa_cleanup during the release") but a potential memory leak is still there as showed by kmemleak if the application does not send VHOST_IOTLB_INVALIDATE or crashes: unreferenced object 0xffff888007fbaa30 (size 16): comm "blkio-bench", pid 914, jiffies 4294993521 (age 885.500s) hex dump (first 16 bytes): 40 73 41 07 80 88 ff ff 00 00 00 00 00 00 00 00 @sA............. backtrace: [<0000000087736d2a>] kmem_cache_alloc_trace+0x142/0x1c0 [<0000000060740f50>] vhost_vdpa_process_iotlb_msg+0x68c/0x901 [vhost_vdpa] [<0000000083e8e205>] vhost_chr_write_iter+0xc0/0x4a0 [vhost] [<000000008f2f414a>] vhost_vdpa_chr_write_iter+0x18/0x20 [vhost_vdpa] [<00000000de1cd4a0>] vfs_write+0x216/0x4b0 [<00000000a2850200>] ksys_write+0x71/0xf0 [<00000000de8e720b>] __x64_sys_write+0x19/0x20 [<0000000018b12cbb>] do_syscall_64+0x3f/0x90 [<00000000986ec465>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Let's fix this calling vhost_vdpa_iotlb_unmap() on the whole range in vhost_vdpa_remove_as(). We move that call before vhost_dev_cleanup() since we need a valid v->vdev.mm in vhost_vdpa_pa_unmap(). vhost_iotlb_reset() call can be removed, since vhost_vdpa_iotlb_unmap() on the whole range removes all the entries. The kmemleak log reported was observed with a vDPA device that has `use_va` set to true (e.g. VDUSE). This patch has been tested with both types of devices.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 3d5698793897a2b9c0060d899881d1a0591630d5 , < 4e92cb33bfb51eee5f28bb10846c46f266a4bb67 (git)
Affected: 3d5698793897a2b9c0060d899881d1a0591630d5 , < a2907867e2c86067accd2f011d6f23ee5533aa6c (git)
Affected: 3d5698793897a2b9c0060d899881d1a0591630d5 , < c070c1912a83432530cbb4271d5b9b11fa36b67a (git)
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    Linux Linux Affected: 5.19
Unaffected: 0 , < 5.19 (semver)
Unaffected: 6.0.19 , ≤ 6.0.* (semver)
Unaffected: 6.1.5 , ≤ 6.1.* (semver)
Unaffected: 6.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/vhost/vdpa.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "lessThan": "4e92cb33bfb51eee5f28bb10846c46f266a4bb67",
              "status": "affected",
              "version": "3d5698793897a2b9c0060d899881d1a0591630d5",
              "versionType": "git"
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              "versionType": "git"
            },
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              "status": "affected",
              "version": "3d5698793897a2b9c0060d899881d1a0591630d5",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/vhost/vdpa.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.0.*",
              "status": "unaffected",
              "version": "6.0.19",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.0.19",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.5",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.2",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvhost-vdpa: fix an iotlb memory leak\n\nBefore commit 3d5698793897 (\"vhost-vdpa: introduce asid based IOTLB\")\nwe called vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1) during\nrelease to free all the resources allocated when processing user IOTLB\nmessages through vhost_vdpa_process_iotlb_update().\nThat commit changed the handling of IOTLB a bit, and we accidentally\nremoved some code called during the release.\n\nWe partially fixed this with commit 037d4305569a (\"vhost-vdpa: call\nvhost_vdpa_cleanup during the release\") but a potential memory leak is\nstill there as showed by kmemleak if the application does not send\nVHOST_IOTLB_INVALIDATE or crashes:\n\n  unreferenced object 0xffff888007fbaa30 (size 16):\n    comm \"blkio-bench\", pid 914, jiffies 4294993521 (age 885.500s)\n    hex dump (first 16 bytes):\n      40 73 41 07 80 88 ff ff 00 00 00 00 00 00 00 00  @sA.............\n    backtrace:\n      [\u003c0000000087736d2a\u003e] kmem_cache_alloc_trace+0x142/0x1c0\n      [\u003c0000000060740f50\u003e] vhost_vdpa_process_iotlb_msg+0x68c/0x901 [vhost_vdpa]\n      [\u003c0000000083e8e205\u003e] vhost_chr_write_iter+0xc0/0x4a0 [vhost]\n      [\u003c000000008f2f414a\u003e] vhost_vdpa_chr_write_iter+0x18/0x20 [vhost_vdpa]\n      [\u003c00000000de1cd4a0\u003e] vfs_write+0x216/0x4b0\n      [\u003c00000000a2850200\u003e] ksys_write+0x71/0xf0\n      [\u003c00000000de8e720b\u003e] __x64_sys_write+0x19/0x20\n      [\u003c0000000018b12cbb\u003e] do_syscall_64+0x3f/0x90\n      [\u003c00000000986ec465\u003e] entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nLet\u0027s fix this calling vhost_vdpa_iotlb_unmap() on the whole range in\nvhost_vdpa_remove_as(). We move that call before vhost_dev_cleanup()\nsince we need a valid v-\u003evdev.mm in vhost_vdpa_pa_unmap().\nvhost_iotlb_reset() call can be removed, since vhost_vdpa_iotlb_unmap()\non the whole range removes all the entries.\n\nThe kmemleak log reported was observed with a vDPA device that has `use_va`\nset to true (e.g. VDUSE). This patch has been tested with both types of\ndevices."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-12-24T13:05:36.801Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/4e92cb33bfb51eee5f28bb10846c46f266a4bb67"
        },
        {
          "url": "https://git.kernel.org/stable/c/a2907867e2c86067accd2f011d6f23ee5533aa6c"
        },
        {
          "url": "https://git.kernel.org/stable/c/c070c1912a83432530cbb4271d5b9b11fa36b67a"
        }
      ],
      "title": "vhost-vdpa: fix an iotlb memory leak",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2022-50738",
    "datePublished": "2025-12-24T13:05:36.801Z",
    "dateReserved": "2025-12-24T13:02:21.542Z",
    "dateUpdated": "2025-12-24T13:05:36.801Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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