{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2021-47493",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix race between searching chunks and release journal_head from buffer_head\n\nEncountered a race between ocfs2_test_bg_bit_allocatable() and\njbd2_journal_put_journal_head() resulting in the below vmcore.\n\n  PID: 106879  TASK: ffff880244ba9c00  CPU: 2   COMMAND: \"loop3\"\n  Call trace:\n    panic\n    oops_end\n    no_context\n    __bad_area_nosemaphore\n    bad_area_nosemaphore\n    __do_page_fault\n    do_page_fault\n    page_fault\n      [exception RIP: ocfs2_block_group_find_clear_bits+316]\n    ocfs2_block_group_find_clear_bits [ocfs2]\n    ocfs2_cluster_group_search [ocfs2]\n    ocfs2_search_chain [ocfs2]\n    ocfs2_claim_suballoc_bits [ocfs2]\n    __ocfs2_claim_clusters [ocfs2]\n    ocfs2_claim_clusters [ocfs2]\n    ocfs2_local_alloc_slide_window [ocfs2]\n    ocfs2_reserve_local_alloc_bits [ocfs2]\n    ocfs2_reserve_clusters_with_limit [ocfs2]\n    ocfs2_reserve_clusters [ocfs2]\n    ocfs2_lock_refcount_allocators [ocfs2]\n    ocfs2_make_clusters_writable [ocfs2]\n    ocfs2_replace_cow [ocfs2]\n    ocfs2_refcount_cow [ocfs2]\n    ocfs2_file_write_iter [ocfs2]\n    lo_rw_aio\n    loop_queue_work\n    kthread_worker_fn\n    kthread\n    ret_from_fork\n\nWhen ocfs2_test_bg_bit_allocatable() called bh2jh(bg_bh), the\nbg_bh->b_private NULL as jbd2_journal_put_journal_head() raced and\nreleased the jounal head from the buffer head.  Needed to take bit lock\nfor the bit 'BH_JournalHead' to fix this race."
            }
        ]
    },
    "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": "1da177e4c3f4",
                                            "version_value": "5043fbd294f5"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "5.10.77",
                                                        "lessThanOrEqual": "5.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.14.16",
                                                        "lessThanOrEqual": "5.14.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.15",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/5043fbd294f5909a080ade0f04b70a4da9e122b7",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/5043fbd294f5909a080ade0f04b70a4da9e122b7"
            },
            {
                "url": "https://git.kernel.org/stable/c/2e382600e8856ea654677b5134ee66e03ea72bc2",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/2e382600e8856ea654677b5134ee66e03ea72bc2"
            },
            {
                "url": "https://git.kernel.org/stable/c/6f1b228529ae49b0f85ab89bcdb6c365df401558",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/6f1b228529ae49b0f85ab89bcdb6c365df401558"
            }
        ]
    },
    "generator": {
        "engine": "bippy-a5840b7849dd"
    }
}