{"id":"AZL-97325","summary":"CVE-2026-74636 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix race between update_event_fields and, event_define_fields\n\nThe following sequence may leads race between event_define_fields()\nand update_event_fields():\n\n CPU0 (loads module A)                      CPU1 (loads module B)\n ===============================            ===============================\n load_module(A)                             load_module(B)\n   notifier_call_chain                        notifier_call_chain\n     trace_module_notify                        trace_module_notify\n       mutex_lock(&event_mutex)                   trace_event_update_all()\n         trace_module_add_events(A)                 down_write(&trace_event_sem)\n            __register_event(call_A)\n              __add_event_to_tracers(call_A)\n                event_define_fields(call_A)\n                  for each f:                         list_for_each_entry(field,\n                    list_add(&f-\u003elink,                                    &class-\u003efields, link)\n                             &class-\u003efields)            field = class-\u003efields-\u003enext;\n\nWhere access to the class-\u003efields is not protected by the event_mutex in\ntrace_event_update_all().\n\nThis produces the following panic:\n   Unable to handle kernel access ... at virtual address 0000000000000018\n   pc : update_event_fields+0xf8/0x368\n   Call trace:\n    update_event_fields+0xf8/0x368\n    trace_event_update_all+0x7c/0x2b4\n    trace_module_notify+0x4c/0x1dc\n    notifier_call_chain+0x84/0x168\n    blocking_notifier_call_chain_robust+0x64/0xd4\n    load_module+0x10c8/0x123c\n    __arm64_sys_finit_module+0x230/0x31c\n\nFix by taking event_mutex in trace_event_update_all() before\ntrace_event_sem.","modified":"2026-08-29T05:27:27Z","published":"2026-08-22T16:16:36Z","upstream":["CVE-2026-74636"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74636"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-97325.json"}}],"schema_version":"1.9.0"}