{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-40998",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix uninitialized ratelimit_state->lock access in __ext4_fill_super()\n\nIn the following concurrency we will access the uninitialized rs->lock:\n\next4_fill_super\n  ext4_register_sysfs\n   // sysfs registered msg_ratelimit_interval_ms\n                             // Other processes modify rs->interval to\n                             // non-zero via msg_ratelimit_interval_ms\n  ext4_orphan_cleanup\n    ext4_msg(sb, KERN_INFO, \"Errors on filesystem, \"\n      __ext4_msg\n        ___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state)\n          if (!rs->interval)  // do nothing if interval is 0\n            return 1;\n          raw_spin_trylock_irqsave(&rs->lock, flags)\n            raw_spin_trylock(lock)\n              _raw_spin_trylock\n                __raw_spin_trylock\n                  spin_acquire(&lock->dep_map, 0, 1, _RET_IP_)\n                    lock_acquire\n                      __lock_acquire\n                        register_lock_class\n                          assign_lock_key\n                            dump_stack();\n  ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);\n    raw_spin_lock_init(&rs->lock);\n    // init rs->lock here\n\nand get the following dump_stack:\n\n=========================================================\nINFO: trying to register non-static key.\nThe code is fine but needs lockdep annotation, or maybe\nyou didn't initialize this object before use?\nturning off the locking correctness validator.\nCPU: 12 PID: 753 Comm: mount Tainted: G E 6.7.0-rc6-next-20231222 #504\n[...]\nCall Trace:\n dump_stack_lvl+0xc5/0x170\n dump_stack+0x18/0x30\n register_lock_class+0x740/0x7c0\n __lock_acquire+0x69/0x13a0\n lock_acquire+0x120/0x450\n _raw_spin_trylock+0x98/0xd0\n ___ratelimit+0xf6/0x220\n __ext4_msg+0x7f/0x160 [ext4]\n ext4_orphan_cleanup+0x665/0x740 [ext4]\n __ext4_fill_super+0x21ea/0x2b10 [ext4]\n ext4_fill_super+0x14d/0x360 [ext4]\n[...]\n=========================================================\n\nNormally interval is 0 until s_msg_ratelimit_state is initialized, so\n___ratelimit() does nothing. But registering sysfs precedes initializing\nrs->lock, so it is possible to change rs->interval to a non-zero value\nvia the msg_ratelimit_interval_ms interface of sysfs while rs->lock is\nuninitialized, and then a call to ext4_msg triggers the problem by\naccessing an uninitialized rs->lock. Therefore register sysfs after all\ninitializations are complete to avoid such problems."
            }
        ]
    },
    "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": "23afcd52af06"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "6.6.36",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.9.7",
                                                        "lessThanOrEqual": "6.9.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.10",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
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    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/23afcd52af06880c6c913a0ad99022b8937b575c",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/23afcd52af06880c6c913a0ad99022b8937b575c"
            },
            {
                "url": "https://git.kernel.org/stable/c/645267906944a9aeec9d5c56ee24a9096a288798",
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                "name": "https://git.kernel.org/stable/c/645267906944a9aeec9d5c56ee24a9096a288798"
            },
            {
                "url": "https://git.kernel.org/stable/c/b4b4fda34e535756f9e774fb2d09c4537b7dfd1c",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/b4b4fda34e535756f9e774fb2d09c4537b7dfd1c"
            }
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}