In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ocfs2: o2hb: quiesce negotiate handlers and timeout work<\/p>\n
Heartbeat regions publish struct o2hb_region as the private data for the
\nNEGO_TIMEOUT and NEGO_APPROVE o2net handlers as soon as make_item()
\ncreates the configfs region. The approve handler can call
\no2hb_arm_timeout(), so a peer can touch the region timeout work before
\ndev_store() has finished building the heartbeat runtime, or after teardown
\nhas started to shut that runtime back down.<\/p>\n
The final configfs put also has to keep reg alive until the last in-flight
\no2net callback drops its handler reference.
\no2net_unregister_handler_list() blocks future handler lookups, but it does
\nnot wait for sc_rx_work that already passed o2net_handler_get(). That
\ndrain needs to cover local listener teardown as well, where the o2net
\nordered workqueue may already be inside destroy_workqueue().<\/p>\n
Fix the lifetime rule in both directions. Initialize the region delayed
\nworks before publishing reg through the o2net handler table, keep new or
\nstopping regions non-armable with hr_stopping, and quiesce both delayed
\nworks on failed-start and teardown paths even when no heartbeat thread is
\nleft to call o2hb_disarm_timeout(). Then unregister handlers before
\ntearing down handler-visible region state and make the drain wait for the
\nactive or destroying o2net ordered workqueue before release frees reg.<\/p>\n
The buggy scenario involves two paths, with each column showing the order
\nwithin that path:<\/p>\n
region lifecycle: late negotiate callback:
\n1. make_item() registers the 1. o2net_process_message() gets a
\n region handlers before heartbeat handler for reg.
\n dev_store() has built a 2. The callback runs after the lookup
\n runnable heartbeat context. lock is dropped and dereferences reg.
\n2. A failed start or rmdir 3. An approve or timeout path tries to
\n stops the heartbeat thread, queue reg’s delayed work, or release
\n quiesces existing work, and races the callback body after handler
\n drops the final configfs ref. unregister.
\n3. region_release() must drain 4. The callback or delayed work can
\n handler-visible o2net rx work outlive reg unless lifecycle code
\n before freeing reg. keeps the region non-armable and
\n drains the active-or-destroying
\n o2net workqueue.<\/p>\n
Validation reproduced this kernel report:
\nKASAN slab-use-after-free in __run_timers+0x22c\/0x5b0
\nWrite of size 8
\nCall trace:
\n dump_stack_lvl+0x66\/0xa0
\n print_report+0xce\/0x630
\n __run_timers+0x22c\/0x5b0
\n kasan_report+0xe0\/0x110
\n _raw_spin_unlock_irqrestore+0x27\/0x60
\n try_to_wake_up+0x191\/0xf70
\n timer_expire_remote+0xae\/0xf0
\n run_timer_softirq+0x19b\/0x1a0
\n handle_softirqs+0x156\/0x660
\n __irq_exit_rcu+0xc4\/0x160
\n irq_exit_rcu+0xe\/0x20
\n sysvec_apic_timer_interrupt+0x6c\/0x80
\n asm_sysvec_apic_timer_interrupt+0x1a\/0x20<\/p>\n
Allocated by task stack:
\n kasan_save_stack+0x33\/0x60
\n kasan_save_track+0x14\/0x30
\n __kasan_kmalloc+0xaa\/0xb0
\n o2hb_heartbeat_group_make_item+0x3c\/0x600<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ocfs2: o2hb: quiesce negotiate handlers and timeout work<\/p>\n
Heartbeat regions publish struct o2hb_region as the private data for the<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-25710","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/25710","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=25710"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25710"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25710"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}