CVE-2022-48890 scsi: storvsc: Fix swiotlb bounce buffer leak in confidential VM

2024-08-2106:10:22

Linux

www.cve.org

linux kernel

vulnerability

cve-2022-48890

memory leak

confidential vm

i/o submission

fix

scsi

storvsc

swiotlb

bounce buffer

EPSS

Percentile

9.5%

JSON

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

scsi: storvsc: Fix swiotlb bounce buffer leak in confidential VM

storvsc_queuecommand() maps the scatter/gather list using scsi_dma_map(),
which in a confidential VM allocates swiotlb bounce buffers. If the I/O
submission fails in storvsc_do_io(), the I/O is typically retried by higher
level code, but the bounce buffer memory is never freed. The mostly like
cause of I/O submission failure is a full VMBus channel ring buffer, which
is not uncommon under high I/O loads. Eventually enough bounce buffer
memory leaks that the confidential VM can’t do any I/O. The same problem
can arise in a non-confidential VM with kernel boot parameter
swiotlb=force.

Fix this by doing scsi_dma_unmap() in the case of an I/O submission
error, which frees the bounce buffer memory.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/scsi/storvsc_drv.c"
    ],
    "versions": [
      {
        "version": "743b237c3a7b",
        "lessThan": "87c71e88f6a6",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "743b237c3a7b",
        "lessThan": "67ff3d0a49f3",
        "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/scsi/storvsc_drv.c"
    ],
    "versions": [
      {
        "version": "5.17",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.17",
        "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"
      }
    ]
  }
]