{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.1",
    "cveMetadata": {
        "cveId": "CVE-2024-39486",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2024-06-25T14:23:23.747Z",
        "datePublished": "2024-07-06T09:25:21.514Z",
        "dateUpdated": "2024-08-02T04:26:15.689Z"
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                "shortName": "Linux",
                "dateUpdated": "2024-07-15T06:50:23.072Z"
            },
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                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/drm_file: Fix pid refcounting race\n\n<maarten.lankhorst@linux.intel.com>, Maxime Ripard\n<mripard@kernel.org>, Thomas Zimmermann <tzimmermann@suse.de>\n\nfilp->pid is supposed to be a refcounted pointer; however, before this\npatch, drm_file_update_pid() only increments the refcount of a struct\npid after storing a pointer to it in filp->pid and dropping the\ndev->filelist_mutex, making the following race possible:\n\nprocess A               process B\n=========               =========\n                        begin drm_file_update_pid\n                        mutex_lock(&dev->filelist_mutex)\n                        rcu_replace_pointer(filp->pid, <pid B>, 1)\n                        mutex_unlock(&dev->filelist_mutex)\nbegin drm_file_update_pid\nmutex_lock(&dev->filelist_mutex)\nrcu_replace_pointer(filp->pid, <pid A>, 1)\nmutex_unlock(&dev->filelist_mutex)\nget_pid(<pid A>)\nsynchronize_rcu()\nput_pid(<pid B>)   *** pid B reaches refcount 0 and is freed here ***\n                        get_pid(<pid B>)   *** UAF ***\n                        synchronize_rcu()\n                        put_pid(<pid A>)\n\nAs far as I know, this race can only occur with CONFIG_PREEMPT_RCU=y\nbecause it requires RCU to detect a quiescent state in code that is not\nexplicitly calling into the scheduler.\n\nThis race leads to use-after-free of a \"struct pid\".\nIt is probably somewhat hard to hit because process A has to pass\nthrough a synchronize_rcu() operation while process B is between\nmutex_unlock() and get_pid().\n\nFix it by ensuring that by the time a pointer to the current task's pid\nis stored in the file, an extra reference to the pid has been taken.\n\nThis fix also removes the condition for synchronize_rcu(); I think\nthat optimization is unnecessary complexity, since in that case we\nwould usually have bailed out on the lockless check above."
                }
            ],
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                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/gpu/drm/drm_file.c"
                    ],
                    "versions": [
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                            "version": "031ddd280089",
                            "lessThan": "16682588ead4",
                            "status": "affected",
                            "versionType": "git"
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                        {
                            "version": "1c7a387ffef8",
                            "lessThan": "0acce2a5c619",
                            "status": "affected",
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                        {
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                            "lessThan": "4f2a129b33a2",
                            "status": "affected",
                            "versionType": "git"
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                    ]
                },
                {
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                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/gpu/drm/drm_file.c"
                    ],
                    "versions": [
                        {
                            "version": "6.7",
                            "status": "affected"
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                        {
                            "version": "0",
                            "lessThan": "6.7",
                            "status": "unaffected",
                            "versionType": "custom"
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                        {
                            "version": "6.6.37",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
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                        },
                        {
                            "version": "6.9.8",
                            "lessThanOrEqual": "6.9.*",
                            "status": "unaffected",
                            "versionType": "custom"
                        },
                        {
                            "version": "6.10",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/16682588ead4a593cf1aebb33b36df4d1e9e4ffa"
                },
                {
                    "url": "https://git.kernel.org/stable/c/0acce2a5c619ef1abdee783d7fea5eac78ce4844"
                },
                {
                    "url": "https://git.kernel.org/stable/c/4f2a129b33a2054e62273edd5a051c34c08d96e9"
                }
            ],
            "title": "drm/drm_file: Fix pid refcounting race",
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                                "timestamp": "2024-07-08T15:13:18.216624Z",
                                "id": "CVE-2024-39486",
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                                        "Exploitation": "none"
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                "title": "CVE Program Container",
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