CVE-2021-47081 habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory

2024-03-0121:15:16

Linux

www.cve.org

cve-2021-47081

habanalabs

gaudi

potential use after free

gaudi_memset_device_memory

uaf

cb->id

AI Score

7.1

Confidence

Low

EPSS

Percentile

9.0%

JSON

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

habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory

Our code analyzer reported a uaf.

In gaudi_memset_device_memory, cb is get via hl_cb_kernel_create()
with 2 refcount.
If hl_cs_allocate_job() failed, the execution runs into release_cb
branch. One ref of cb is dropped by hl_cb_put(cb) and could be freed
if other thread also drops one ref. Then cb is used by cb->id later,
which is a potential uaf.

My patch add a variable ‘id’ to accept the value of cb->id before the
hl_cb_put(cb) is called, to avoid the potential uaf.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/misc/habanalabs/gaudi/gaudi.c"
    ],
    "versions": [
      {
        "version": "423815bf02e2",
        "lessThan": "b49f5af30b0e",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "423815bf02e2",
        "lessThan": "115726c5d312",
        "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/misc/habanalabs/gaudi/gaudi.c"
    ],
    "versions": [
      {
        "version": "5.12",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.12",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.7",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]