cve/published/2021/CVE-2021-47200.json

{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/prime: Fix use after free in mmap with drm_gem_ttm_mmap\n\ndrm_gem_ttm_mmap() drops a reference to the gem object on success. If\nthe gem object's refcount == 1 on entry to drm_gem_prime_mmap(), that\ndrop will free the gem object, and the subsequent drm_gem_object_get()\nwill be a UAF. Fix by grabbing a reference before calling the mmap\nhelper.\n\nThis issue was forseen when the reference dropping was adding in\ncommit 9786b65bc61ac (\"drm/ttm: fix mmap refcounting\"):\n  \"For that to work properly the drm_gem_object_get() call in\n  drm_gem_ttm_mmap() must be moved so it happens before calling\n  obj->funcs->mmap(), otherwise the gem refcount would go down\n  to zero.\""
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "drivers/gpu/drm/drm_prime.c"
               ],
               "versions": [
                  {
                     "version": "9786b65bc61acec63f923978c75e707afbb74bc7",
                     "lessThan": "4f8e469a2384dfa4047145b0093126462cbb6dc0",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "9786b65bc61acec63f923978c75e707afbb74bc7",
                     "lessThan": "8244a3bc27b3efd057da154b8d7e414670d5044f",
                     "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/gpu/drm/drm_prime.c"
               ],
               "versions": [
                  {
                     "version": "5.5",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "5.5",
                     "status": "unaffected",
                     "versionType": "semver"
                  },
                  {
                     "version": "5.15.5",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "semver"
                  },
                  {
                     "version": "5.16",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "cpeApplicability": [
            {
               "nodes": [
                  {
                     "operator": "OR",
                     "negate": false,
                     "cpeMatch": [
                        {
                           "vulnerable": true,
                           "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                           "versionStartIncluding": "5.5",
                           "versionEndExcluding": "5.15.5"
                        },
                        {
                           "vulnerable": true,
                           "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                           "versionStartIncluding": "5.5",
                           "versionEndExcluding": "5.16"
                        }
                     ]
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/4f8e469a2384dfa4047145b0093126462cbb6dc0"
            },
            {
               "url": "https://git.kernel.org/stable/c/8244a3bc27b3efd057da154b8d7e414670d5044f"
            }
         ],
         "title": "drm/prime: Fix use after free in mmap with drm_gem_ttm_mmap",
         "x_generator": {
            "engine": "bippy-1.2.0"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2021-47200",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}