{"id":"AZL-67767","summary":"CVE-2024-40998 affecting package kernel 5.15.200.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix uninitialized ratelimit_state-\u003elock access in __ext4_fill_super()\n\nIn the following concurrency we will access the uninitialized rs-\u003elock:\n\next4_fill_super\n  ext4_register_sysfs\n   // sysfs registered msg_ratelimit_interval_ms\n                             // Other processes modify rs-\u003einterval 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)-\u003es_msg_ratelimit_state)\n          if (!rs-\u003einterval)  // do nothing if interval is 0\n            return 1;\n          raw_spin_trylock_irqsave(&rs-\u003elock, flags)\n            raw_spin_trylock(lock)\n              _raw_spin_trylock\n                __raw_spin_trylock\n                  spin_acquire(&lock-\u003edep_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-\u003es_msg_ratelimit_state, 5 * HZ, 10);\n    raw_spin_lock_init(&rs-\u003elock);\n    // init rs-\u003elock 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-\u003elock, so it is possible to change rs-\u003einterval to a non-zero value\nvia the msg_ratelimit_interval_ms interface of sysfs while rs-\u003elock is\nuninitialized, and then a call to ext4_msg triggers the problem by\naccessing an uninitialized rs-\u003elock. Therefore register sysfs after all\ninitializations are complete to avoid such problems.","modified":"2026-04-01T05:21:50.075893Z","published":"2024-07-12T13:15:20Z","upstream":["CVE-2024-40998"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-40998"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"5.15.200.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-67767.json"}}],"schema_version":"1.7.5"}