================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x74/0x1ff0 kernel/locking/lockdep.c:4882 Read of size 8 at addr ffff8880620f45a8 by task kworker/u4:4/1434 CPU: 0 PID: 1434 Comm: kworker/u4:4 Not tainted 5.15.156-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 __lock_acquire+0x74/0x1ff0 kernel/locking/lockdep.c:4882 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4030 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:debug_lockdep_rcu_enabled+0x25/0x30 kernel/rcu/update.c:281 Code: cc cc cc cc cc 31 c0 83 3d ab b8 c6 03 00 74 1d 83 3d 22 eb c6 03 00 74 14 65 48 8b 0d 54 cc e4 75 31 c0 83 b9 ec 0a 00 00 00 <0f> 94 c0 c3 cc cc cc cc cc cc cc 41 56 53 89 fb e8 d6 0d 00 00 41 RSP: 0018:ffffc9000585f938 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000055b8f RCX: ffff88801ea78000 RDX: 0000000000000000 RSI: ffffffff8a8b3c20 RDI: ffffffff8ad8f380 RBP: ffffc9000585fa50 R08: dffffc0000000000 R09: fffffbfff1bc8b5e R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 1ffffffff1b78b04 R14: dffffc0000000000 R15: 1ffff92000b0bf30 ___might_sleep+0xdc/0x6a0 kernel/sched/core.c:9592 inet_twsk_purge+0x10f/0xa20 net/ipv4/inet_timewait_sock.c:267 ops_exit_list net/core/net_namespace.c:174 [inline] cleanup_net+0x763/0xb60 net/core/net_namespace.c:596 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Allocated by task 2: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] kmem_cache_alloc_node+0x121/0x2c0 mm/slub.c:3256 alloc_task_struct_node kernel/fork.c:171 [inline] dup_task_struct+0x57/0xb60 kernel/fork.c:894 copy_process+0x5eb/0x3ef0 kernel/fork.c:2038 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 create_kthread kernel/kthread.c:357 [inline] kthreadd+0x57a/0x740 kernel/kthread.c:701 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Freed by task 14: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 rcu_do_batch kernel/rcu/tree.c:2523 [inline] rcu_core+0xa15/0x1650 kernel/rcu/tree.c:2763 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 Last potentially related work creation: kasan_save_stack+0x36/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3007 [inline] call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3087 context_switch kernel/sched/core.c:5033 [inline] __schedule+0x12cc/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 nilfs_segctor_kill_thread fs/nilfs2/segment.c:2681 [inline] nilfs_segctor_destroy fs/nilfs2/segment.c:2763 [inline] nilfs_detach_log_writer+0x2e6/0xbd0 fs/nilfs2/segment.c:2852 nilfs_put_super+0x49/0x150 fs/nilfs2/super.c:498 generic_shutdown_super+0x136/0x2c0 fs/super.c:475 kill_block_super+0x7a/0xe0 fs/super.c:1414 deactivate_locked_super+0xa0/0x110 fs/super.c:335 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143 task_work_run+0x129/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Second to last potentially related work creation: kasan_save_stack+0x36/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3007 [inline] call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3087 context_switch kernel/sched/core.c:5033 [inline] __schedule+0x12cc/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845 synchronize_rcu+0x107/0x1a0 kernel/rcu/tree.c:3798 lockdep_unregister_key+0x4e6/0x5b0 kernel/locking/lockdep.c:6319 wq_unregister_lockdep kernel/workqueue.c:3518 [inline] pwq_unbound_release_workfn+0x23d/0x290 kernel/workqueue.c:3756 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 The buggy address belongs to the object at ffff8880620f3b80 which belongs to the cache task_struct of size 7360 The buggy address is located 2600 bytes inside of 7360-byte region [ffff8880620f3b80, ffff8880620f5840) The buggy address belongs to the page: page:ffffea0001883c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880620f0000 pfn:0x620f0 head:ffffea0001883c00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff888022236f41 flags: 0xfff80000010200(slab|head|node=0|zone=1|lastcpupid=0xfff) raw: 00fff80000010200 ffffea000188e808 ffffea000074d608 ffff888011deb3c0 raw: ffff8880620f0000 0000000000040003 00000001ffffffff ffff888022236f41 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2, ts 43139945601, free_ts 10988187725 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5423 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] kmem_cache_alloc_node+0x1ba/0x2c0 mm/slub.c:3256 alloc_task_struct_node kernel/fork.c:171 [inline] dup_task_struct+0x57/0xb60 kernel/fork.c:894 copy_process+0x5eb/0x3ef0 kernel/fork.c:2038 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 create_kthread kernel/kthread.c:357 [inline] kthreadd+0x57a/0x740 kernel/kthread.c:701 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_contig_range+0x95/0xf0 mm/page_alloc.c:9342 destroy_args+0xfe/0x980 mm/debug_vm_pgtable.c:1018 debug_vm_pgtable+0x40d/0x470 mm/debug_vm_pgtable.c:1331 do_one_initcall+0x22b/0x7a0 init/main.c:1300 do_initcall_level+0x157/0x210 init/main.c:1373 do_initcalls+0x49/0x90 init/main.c:1389 kernel_init_freeable+0x425/0x5c0 init/main.c:1613 kernel_init+0x19/0x290 init/main.c:1504 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Memory state around the buggy address: ffff8880620f4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880620f4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880620f4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880620f4600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880620f4680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: cc int3 1: cc int3 2: cc int3 3: cc int3 4: cc int3 5: 31 c0 xor %eax,%eax 7: 83 3d ab b8 c6 03 00 cmpl $0x0,0x3c6b8ab(%rip) # 0x3c6b8b9 e: 74 1d je 0x2d 10: 83 3d 22 eb c6 03 00 cmpl $0x0,0x3c6eb22(%rip) # 0x3c6eb39 17: 74 14 je 0x2d 19: 65 48 8b 0d 54 cc e4 mov %gs:0x75e4cc54(%rip),%rcx # 0x75e4cc75 20: 75 21: 31 c0 xor %eax,%eax 23: 83 b9 ec 0a 00 00 00 cmpl $0x0,0xaec(%rcx) * 2a: 0f 94 c0 sete %al <-- trapping instruction 2d: c3 ret 2e: cc int3 2f: cc int3 30: cc int3 31: cc int3 32: cc int3 33: cc int3 34: cc int3 35: 41 56 push %r14 37: 53 push %rbx 38: 89 fb mov %edi,%ebx 3a: e8 d6 0d 00 00 call 0xe15 3f: 41 rex.B