CVE-2026-90302
ocfs2: synchronize heartbeat callbacks with o2net teardown
Description
In the Linux kernel, the following vulnerability has been resolved: ocfs2: synchronize heartbeat callbacks with o2net teardown Patch series "ocfs2: harden heartbeat teardown races". This series fixes two OCFS2 heartbeat/o2net teardown races found by KASAN. This patch (of 2): Heartbeat callbacks stay registered while configfs local-node teardown enters o2net_stop_listening(). A node-down event can still run through o2net_disconnect_node() and o2net_set_nn_state() while teardown is destroying o2net_wq, so the later queue/flush operations can hit a dead workqueue. KASAN has caught this as a slab-use-after-free in __queue_work() with the call chain: KASAN slab-use-after-free in __queue_work+0x56/0xa90 Read of size 4 Call trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 __queue_work+0x56/0xa90 srso_alias_return_thunk+0x5/0xfbef5 __virt_addr_valid+0x19f/0x330 kasan_report+0xe0/0x110 __queue_delayed_work+0x58/0x1e0 queue_delayed_work_on+0xb4/0xc0 o2net_set_nn_state+0x467/0x840 o2net_disconnect_node+0x7b/0xe0 o2net_hb_node_down_cb+0x54/0x60 o2hb_run_event_list+0x236/0x2d0 o2hb_check_slot+0xad4/0xbc0 lock_release+0xc8/0x290 o2hb_check_slot+0x9ea/0xbc0 trace_hardirqs_on+0x18/0x130 o2hb_do_disk_heartbeat+0x646/0xb30 (fs/ocfs2/cluster/heartbeat.c:1079) __lock_acquire+0x466/0x2260 lockdep_hardirqs_on_prepare+0xea/0x1a0 ktime_get_with_offset+0xe9/0x230 o2hb_thread+0x14e/0x770 kthread+0x1ad/0x1f0 ret_from_fork+0x3c9/0x540 __switch_to+0x2e9/0x730 ret_from_fork_asm+0x1a/0x30 Allocated by task stack: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 __kmalloc_noprof+0x292/0x760 __alloc_workqueue+0x736/0xc60 alloc_workqueue_noprof+0xb1/0x110 o2net_start_listening+0xe5/0x430 o2nm_node_local_store+0x184/0x310 configfs_write_iter+0x18a/0x210 vfs_write+0x469/0x810 ksys_write+0xd2/0x170 do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task stack: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x5f/0x80 kfree+0x313/0x590 rcu_core+0x4f4/0x1320 handle_softirqs+0x156/0x660 queue_delayed_work_on o2net_set_nn_state o2net_disconnect_node o2net_hb_node_down_cb o2hb_run_event_list Keep heartbeat callbacks registered so quorum state still tracks node state, but stop them from driving o2net reconnect/disconnect work once local teardown starts. Mark the transport offline before destroying o2net_wq, wait for any in-flight heartbeat callback to finish, and delay bring-up replay until the new local node is published through o2nm_this_node(). The replay also has to stay serialized with heartbeat callback delivery. Otherwise a live-node snapshot can be copied, a real hb_down callback can install -ENOTCONN for a peer, and the stale replay can call o2net_hb_node_up() for that same peer and queue reconnect work even though heartbeat is already down. The buggy scenario involves two paths, with each column showing the order within that path: local-node teardown: heartbeat node-down callback: 1. configfs local-off enters 1. o2hb_run_event_list() invokes o2net_stop_listening(). o2net_hb_node_down_cb(). 2. teardown heads for 2. the callback reaches destroy_workqueue(o2net_wq). o2net_disconnect_node() and o2net_set_nn_state(). 3. teardown destroys and NULLs 3. the callback flushes or queues o2net_wq. work through o2net_wq.
INFO
Published Date :
Sept. 17, 2026, 5:17 p.m.
Last Modified :
Sept. 17, 2026, 5:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to a patched version.
- Apply the OCFS2 heartbeat harden teardown races patch series.
- Synchronize heartbeat callbacks with o2net teardown.
- Ensure transport is offline before destroying workqueue.
References to Advisories, Solutions, and Tools
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information, practical solutions, and valuable tools related to
CVE-2026-90302.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-90302 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-90302
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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CVE-2026-90302 vulnerability anywhere in the article.
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CVE-2026-90302 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 17, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: ocfs2: synchronize heartbeat callbacks with o2net teardown Patch series "ocfs2: harden heartbeat teardown races". This series fixes two OCFS2 heartbeat/o2net teardown races found by KASAN. This patch (of 2): Heartbeat callbacks stay registered while configfs local-node teardown enters o2net_stop_listening(). A node-down event can still run through o2net_disconnect_node() and o2net_set_nn_state() while teardown is destroying o2net_wq, so the later queue/flush operations can hit a dead workqueue. KASAN has caught this as a slab-use-after-free in __queue_work() with the call chain: KASAN slab-use-after-free in __queue_work+0x56/0xa90 Read of size 4 Call trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 __queue_work+0x56/0xa90 srso_alias_return_thunk+0x5/0xfbef5 __virt_addr_valid+0x19f/0x330 kasan_report+0xe0/0x110 __queue_delayed_work+0x58/0x1e0 queue_delayed_work_on+0xb4/0xc0 o2net_set_nn_state+0x467/0x840 o2net_disconnect_node+0x7b/0xe0 o2net_hb_node_down_cb+0x54/0x60 o2hb_run_event_list+0x236/0x2d0 o2hb_check_slot+0xad4/0xbc0 lock_release+0xc8/0x290 o2hb_check_slot+0x9ea/0xbc0 trace_hardirqs_on+0x18/0x130 o2hb_do_disk_heartbeat+0x646/0xb30 (fs/ocfs2/cluster/heartbeat.c:1079) __lock_acquire+0x466/0x2260 lockdep_hardirqs_on_prepare+0xea/0x1a0 ktime_get_with_offset+0xe9/0x230 o2hb_thread+0x14e/0x770 kthread+0x1ad/0x1f0 ret_from_fork+0x3c9/0x540 __switch_to+0x2e9/0x730 ret_from_fork_asm+0x1a/0x30 Allocated by task stack: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 __kmalloc_noprof+0x292/0x760 __alloc_workqueue+0x736/0xc60 alloc_workqueue_noprof+0xb1/0x110 o2net_start_listening+0xe5/0x430 o2nm_node_local_store+0x184/0x310 configfs_write_iter+0x18a/0x210 vfs_write+0x469/0x810 ksys_write+0xd2/0x170 do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task stack: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x5f/0x80 kfree+0x313/0x590 rcu_core+0x4f4/0x1320 handle_softirqs+0x156/0x660 queue_delayed_work_on o2net_set_nn_state o2net_disconnect_node o2net_hb_node_down_cb o2hb_run_event_list Keep heartbeat callbacks registered so quorum state still tracks node state, but stop them from driving o2net reconnect/disconnect work once local teardown starts. Mark the transport offline before destroying o2net_wq, wait for any in-flight heartbeat callback to finish, and delay bring-up replay until the new local node is published through o2nm_this_node(). The replay also has to stay serialized with heartbeat callback delivery. Otherwise a live-node snapshot can be copied, a real hb_down callback can install -ENOTCONN for a peer, and the stale replay can call o2net_hb_node_up() for that same peer and queue reconnect work even though heartbeat is already down. The buggy scenario involves two paths, with each column showing the order within that path: local-node teardown: heartbeat node-down callback: 1. configfs local-off enters 1. o2hb_run_event_list() invokes o2net_stop_listening(). o2net_hb_node_down_cb(). 2. teardown heads for 2. the callback reaches destroy_workqueue(o2net_wq). o2net_disconnect_node() and o2net_set_nn_state(). 3. teardown destroys and NULLs 3. the callback flushes or queues o2net_wq. work through o2net_wq. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/90xxx/CVE-2026-90302.json">CVE-2026-90302</a> Added Reference https://git.kernel.org/stable/c/073f51e39bed354452a057d38a4cc3952727c304 Added Reference https://git.kernel.org/stable/c/3e326f3bf16506873777444608e8b715aab74a7a Added Reference https://git.kernel.org/stable/c/7601db4c9d3bd9ab2482a863cb05204154d51ae8 Added Reference https://git.kernel.org/stable/c/8f96b78314cff0778a3466e49e5edbc1e459c95c Added Reference https://git.kernel.org/stable/c/a03078a9a2a1c5e4a62f65d389c1f75f9898e21d Added Reference https://git.kernel.org/stable/c/aee687a2fb36974dc37e4e0f5b03802067c6c4ec Added Reference https://git.kernel.org/stable/c/cbb4efc2f99d6a8dba09c96b10acad82da982cf9 Added Reference https://git.kernel.org/stable/c/fb61882e184ee5ca745806bc5b2a8483fa129bca