{"cve":"CVE-2026-90302","nvd":{"published":"2026-09-17T17:17:27.723","modified":"2026-10-19T09:19:24.177","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: synchronize heartbeat callbacks with o2net teardown\n\nPatch series \"ocfs2: harden heartbeat teardown races\".\n\nThis series fixes two OCFS2 heartbeat/o2net teardown races found by\nKASAN.\n\n\nThis patch (of 2):\n\nHeartbeat callbacks stay registered while configfs local-node teardown\nenters o2net_stop_listening().  A node-down event can still run through\no2net_disconnect_node() and o2net_set_nn_state() while teardown is\ndestroying o2net_wq, so the later queue/flush operations can hit a dead\nworkqueue.  KASAN has caught this as a slab-use-after-free in\n__queue_work() with the call chain:\n\nKASAN slab-use-after-free in __queue_work+0x56/0xa90\nRead of size 4\nCall trace:\n  dump_stack_lvl+0x66/0xa0\n  print_report+0xce/0x630\n  __queue_work+0x56/0xa90\n  srso_alias_return_thunk+0x5/0xfbef5\n  __virt_addr_valid+0x19f/0x330\n  kasan_report+0xe0/0x110\n  __queue_delayed_work+0x58/0x1e0\n  queue_delayed_work_on+0xb4/0xc0\n  o2net_set_nn_state+0x467/0x840\n  o2net_disconnect_node+0x7b/0xe0\n  o2net_hb_node_down_cb+0x54/0x60\n  o2hb_run_event_list+0x236/0x2d0\n  o2hb_check_slot+0xad4/0xbc0\n  lock_release+0xc8/0x290\n  o2hb_check_slot+0x9ea/0xbc0\n  trace_hardirqs_on+0x18/0x130\n  o2hb_do_disk_heartbeat+0x646/0xb30 (fs/ocfs2/cluster/heartbeat.c:1079)\n  __lock_acquire+0x466/0x2260\n  lockdep_hardirqs_on_prepare+0xea/0x1a0\n  ktime_get_with_offset+0xe9/0x230\n  o2hb_thread+0x14e/0x770\n  kthread+0x1ad/0x1f0\n  ret_from_fork+0x3c9/0x540\n  __switch_to+0x2e9/0x730\n  ret_from_fork_asm+0x1a/0x30\nAllocated by task stack:\n  kasan_save_stack+0x33/0x60\n  kasan_save_track+0x14/0x30\n  __kasan_kmalloc+0xaa/0xb0\n  __kmalloc_noprof+0x292/0x760\n  __alloc_workqueue+0x736/0xc60\n  alloc_workqueue_noprof+0xb1/0x110\n  o2net_start_listening+0xe5/0x430\n  o2nm_node_local_store+0x184/0x310\n  configfs_write_iter+0x18a/0x210\n  vfs_write+0x469/0x810\n  ksys_write+0xd2/0x170\n  do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n  entry_SYSCALL_64_after_hwframe+0x77/0x7f\nFreed by task stack:\n  kasan_save_stack+0x33/0x60\n  kasan_save_track+0x14/0x30\n  kasan_save_free_info+0x3b/0x60\n  __kasan_slab_free+0x5f/0x80\n  kfree+0x313/0x590\n  rcu_core+0x4f4/0x1320\n  handle_softirqs+0x156/0x660\n\nqueue_delayed_work_on\no2net_set_nn_state\no2net_disconnect_node\no2net_hb_node_down_cb\no2hb_run_event_list\n\nKeep heartbeat callbacks registered so quorum state still tracks node\nstate, but stop them from driving o2net reconnect/disconnect work once\nlocal teardown starts. Mark the transport offline before destroying\no2net_wq, wait for any in-flight heartbeat callback to finish, and delay\nbring-up replay until the new local node is published through\no2nm_this_node().\n\nThe replay also has to stay serialized with heartbeat callback delivery.\nOtherwise a live-node snapshot can be copied, a real hb_down callback\ncan install -ENOTCONN for a peer, and the stale replay can call\no2net_hb_node_up() for that same peer and queue reconnect work even\nthough heartbeat is already down.\n\nThe buggy scenario involves two paths, with each column showing the order\nwithin that path:\n\nlocal-node teardown:                 heartbeat node-down callback:\n1. configfs local-off enters         1. o2hb_run_event_list() invokes\n   o2net_stop_listening().              o2net_hb_node_down_cb().\n2. teardown heads for                2. the callback reaches\n   destroy_workqueue(o2net_wq).         o2net_disconnect_node() and\n                                        o2net_set_nn_state().\n3. teardown destroys and NULLs       3. the callback flushes or queues\n   o2net_wq.                            work through o2net_wq.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/073f51e39bed354452a057d38a4cc3952727c304","https://git.kernel.org/stable/c/3e326f3bf16506873777444608e8b715aab74a7a","https://git.kernel.org/stable/c/7601db4c9d3bd9ab2482a863cb05204154d51ae8","https://git.kernel.org/stable/c/8f96b78314cff0778a3466e49e5edbc1e459c95c","https://git.kernel.org/stable/c/a03078a9a2a1c5e4a62f65d389c1f75f9898e21d"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-90302","score":0.00216,"percentile":0.11956,"date":"2026-10-25"},"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."]}