================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x114/0x75e8 kernel/locking/lockdep.c:5004 Read of size 8 at addr ffff0000c4ec5cd8 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.6.0-rc4-syzkaller-00158-gf291209eca5e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x174/0x514 mm/kasan/report.c:475 kasan_report+0xd8/0x138 mm/kasan/report.c:588 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __lock_acquire+0x114/0x75e8 kernel/locking/lockdep.c:5004 lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5753 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x5c/0x7c kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:518 [inline] try_to_wake_up+0xb0/0xe80 kernel/sched/core.c:4230 wake_up_process+0x18/0x24 kernel/sched/core.c:4478 nilfs_construction_timeout+0x40/0x50 fs/nilfs2/segment.c:2444 call_timer_fn+0x19c/0x8cc kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x55c/0x734 kernel/time/timer.c:2022 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:2035 __do_softirq+0x2d0/0xd54 kernel/softirq.c:553 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:882 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85 invoke_softirq kernel/softirq.c:434 [inline] __irq_exit_rcu+0x200/0x494 kernel/softirq.c:632 irq_exit_rcu+0x14/0x84 kernel/softirq.c:644 __el1_irq arch/arm64/kernel/entry-common.c:503 [inline] el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:517 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:522 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:587 __daif_local_irq_enable arch/arm64/include/asm/irqflags.h:33 [inline] arch_local_irq_enable+0x8/0xc arch/arm64/include/asm/irqflags.h:55 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1f0/0x4e8 kernel/sched/idle.c:282 cpu_startup_entry+0x5c/0x74 kernel/sched/idle.c:380 rest_init+0x2dc/0x2f4 init/main.c:726 start_kernel+0x0/0x54c init/main.c:823 start_kernel+0x3e0/0x54c init/main.c:1068 __primary_switched+0xb8/0xc0 arch/arm64/kernel/head.S:523 Allocated by task 2: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x7c mm/kasan/common.c:52 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:511 __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x90/0x4a0 mm/slab.h:762 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x2c8/0x46c mm/slub.c:3523 alloc_task_struct_node kernel/fork.c:173 [inline] dup_task_struct+0x74/0x888 kernel/fork.c:1110 copy_process+0x488/0x34b8 kernel/fork.c:2327 kernel_clone+0x1d8/0x854 kernel/fork.c:2909 kernel_thread+0x184/0x200 kernel/fork.c:2971 create_kthread kernel/kthread.c:411 [inline] kthreadd+0x464/0x670 kernel/kthread.c:746 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:853 Freed by task 6559: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x7c mm/kasan/common.c:52 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:522 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook mm/slub.c:1826 [inline] slab_free mm/slub.c:3809 [inline] kmem_cache_free+0x2e4/0x56c mm/slub.c:3831 free_task_struct kernel/fork.c:178 [inline] free_task+0xe8/0x14c kernel/fork.c:627 __put_task_struct+0x178/0x210 kernel/fork.c:981 put_task_struct+0x88/0x10c include/linux/sched/task.h:136 delayed_put_task_struct+0xdc/0x2d8 kernel/exit.c:226 rcu_do_batch kernel/rcu/tree.c:2139 [inline] rcu_core+0x8a4/0x1b28 kernel/rcu/tree.c:2403 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2420 __do_softirq+0x2d0/0xd54 kernel/softirq.c:553 Last potentially related work creation: kasan_save_stack+0x40/0x6c mm/kasan/common.c:45 __kasan_record_aux_stack+0xcc/0xe8 mm/kasan/generic.c:492 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:502 __call_rcu_common kernel/rcu/tree.c:2653 [inline] call_rcu+0x104/0xaf4 kernel/rcu/tree.c:2767 put_task_struct_rcu_user+0x70/0xd8 kernel/exit.c:232 finish_task_switch+0x5b4/0x614 kernel/sched/core.c:5289 context_switch kernel/sched/core.c:5385 [inline] __schedule+0x13e8/0x244c kernel/sched/core.c:6695 schedule+0xc4/0x170 kernel/sched/core.c:6771 nilfs_segctor_kill_thread fs/nilfs2/segment.c:2679 [inline] nilfs_segctor_destroy fs/nilfs2/segment.c:2761 [inline] nilfs_detach_log_writer+0x280/0xa48 fs/nilfs2/segment.c:2850 nilfs_put_super+0x4c/0x130 fs/nilfs2/super.c:499 generic_shutdown_super+0x130/0x2b8 fs/super.c:693 kill_block_super+0x40/0x74 fs/super.c:1646 deactivate_locked_super+0xac/0x12c fs/super.c:481 deactivate_super+0xe0/0x100 fs/super.c:514 cleanup_mnt+0x34c/0x3dc fs/namespace.c:1254 __cleanup_mnt+0x20/0x30 fs/namespace.c:1261 task_work_run+0x230/0x2e0 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x2184/0x3c94 arch/arm64/kernel/signal.c:1305 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:144 [inline] el0_svc+0xa0/0x16c arch/arm64/kernel/entry-common.c:679 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Second to last potentially related work creation: kasan_save_stack+0x40/0x6c mm/kasan/common.c:45 __kasan_record_aux_stack+0xcc/0xe8 mm/kasan/generic.c:492 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:502 __call_rcu_common kernel/rcu/tree.c:2653 [inline] call_rcu+0x104/0xaf4 kernel/rcu/tree.c:2767 release_task+0x145c/0x1544 wait_task_zombie kernel/exit.c:1210 [inline] wait_consider_task+0x15d0/0x2660 kernel/exit.c:1437 do_wait_pid kernel/exit.c:1568 [inline] do_wait+0x5c4/0xac8 kernel/exit.c:1610 kernel_wait4+0x24c/0x3d8 kernel/exit.c:1780 __do_sys_wait4 kernel/exit.c:1808 [inline] __se_sys_wait4 kernel/exit.c:1804 [inline] __arm64_sys_wait4+0x11c/0x2a0 kernel/exit.c:1804 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x58/0x16c arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 The buggy address belongs to the object at ffff0000c4ec5340 which belongs to the cache task_struct of size 6848 The buggy address is located 2456 bytes inside of freed 6848-byte region [ffff0000c4ec5340, ffff0000c4ec6e00) The buggy address belongs to the physical page: page:00000000eeb1ceb9 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x104ec0 head:00000000eeb1ceb9 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000840(slab|head|node=0|zone=2|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 05ffc00000000840 ffff0000c185c500 fffffc0003113200 dead000000000002 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000c4ec5b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000c4ec5c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000c4ec5c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000c4ec5d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000c4ec5d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================