{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2021-47200",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "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.\""
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "9786b65bc61a",
                                            "version_value": "4f8e469a2384"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "5.5",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "5.5",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.15.5",
                                                        "lessThanOrEqual": "5.15.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.16",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/4f8e469a2384dfa4047145b0093126462cbb6dc0",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/4f8e469a2384dfa4047145b0093126462cbb6dc0"
            },
            {
                "url": "https://git.kernel.org/stable/c/8244a3bc27b3efd057da154b8d7e414670d5044f",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/8244a3bc27b3efd057da154b8d7e414670d5044f"
            }
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