{"cve":"CVE-2024-40998","nvd":{"published":"2024-07-12T13:15:20.857","modified":"2026-10-30T13:17:30.080","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-908"],"references":["https://git.kernel.org/stable/c/1e2df0ee0afd6d4b436a740f04f7a759e6531005","https://git.kernel.org/stable/c/23afcd52af06880c6c913a0ad99022b8937b575c","https://git.kernel.org/stable/c/645267906944a9aeec9d5c56ee24a9096a288798","https://git.kernel.org/stable/c/b4b4fda34e535756f9e774fb2d09c4537b7dfd1c","https://git.kernel.org/stable/c/23afcd52af06880c6c913a0ad99022b8937b575c"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-30T13:47:47.119061695+00:00"},"epss":{"cve":"CVE-2024-40998","score":0.00271,"percentile":0.19535,"date":"2026-10-30"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}