================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x78/0x1fd0 kernel/locking/lockdep.c:5005 Read of size 8 at addr ffff88801abf0a10 by task syz-executor.3/6630 CPU: 0 PID: 6630 Comm: syz-executor.3 Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 __lock_acquire+0x78/0x1fd0 kernel/locking/lockdep.c:5005 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline] try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1793 expire_timers kernel/time/timer.c:1844 [inline] __run_timers kernel/time/timer.c:2418 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2429 run_timer_base kernel/time/timer.c:2438 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2448 __do_softirq+0x2c6/0x980 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_flush_all+0xaad/0xfd0 kernel/printk/printk.c:2985 Code: ff ff e8 26 97 1f 00 90 0f 0b 90 e9 d8 f8 ff ff e8 18 97 1f 00 e8 93 85 00 0a 4d 85 f6 74 b6 e8 09 97 1f 00 fb 48 8b 44 24 70 <42> 0f b6 04 38 84 c0 48 8b 7c 24 30 0f 85 22 02 00 00 0f b6 1f 31 RSP: 0018:ffffc90009906a00 EFLAGS: 00000293 RAX: 1ffff92001320d8c RBX: 0000000000000000 RCX: ffff888026550000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90009906bb0 R08: ffffffff81766904 R09: 1ffffffff25df6a0 R10: dffffc0000000000 R11: fffffbfff25df6a1 R12: ffffffff8eb01bd8 R13: ffffffff8eb01b80 R14: 0000000000000200 R15: dffffc0000000000 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3048 vprintk_emit+0x5a6/0x770 kernel/printk/printk.c:2348 _printk+0xd5/0x120 kernel/printk/printk.c:2373 __nilfs_msg+0x34d/0x420 fs/nilfs2/super.c:79 nilfs_clear_folio_dirty+0x1f5/0x8f0 fs/nilfs2/page.c:406 nilfs_clear_dirty_pages+0x20d/0x3c0 fs/nilfs2/page.c:383 nilfs_writepages+0x11c/0x160 fs/nilfs2/inode.c:165 do_writepages+0x359/0x870 mm/page-writeback.c:2612 __writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1650 writeback_single_inode+0x21b/0x7a0 fs/fs-writeback.c:1771 write_inode_now+0x1d1/0x260 fs/fs-writeback.c:2813 iput_final fs/inode.c:1728 [inline] iput+0x5d7/0x930 fs/inode.c:1767 nilfs_dispose_list+0x51d/0x5c0 fs/nilfs2/segment.c:820 nilfs_segctor_destroy fs/nilfs2/segment.c:2741 [inline] nilfs_detach_log_writer+0x7d4/0xbe0 fs/nilfs2/segment.c:2816 nilfs_put_super+0x4d/0x160 fs/nilfs2/super.c:499 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 deactivate_locked_super+0xc4/0x130 fs/super.c:472 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3b3567f1d7 Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffef5765578 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f3b3567f1d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffef5765630 RBP: 00007ffef5765630 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffef57666f0 R13: 00007f3b356c93b9 R14: 000000000003df3f R15: 000000000000001a Allocated by task 2: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3798 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc_node+0x194/0x380 mm/slub.c:3888 alloc_task_struct_node kernel/fork.c:176 [inline] dup_task_struct+0x57/0x7d0 kernel/fork.c:1107 copy_process+0x5d1/0x3df0 kernel/fork.c:2220 kernel_clone+0x223/0x870 kernel/fork.c:2797 kernel_thread+0x1bc/0x240 kernel/fork.c:2859 create_kthread kernel/kthread.c:411 [inline] kthreadd+0x60d/0x810 kernel/kthread.c:764 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 15: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2106 [inline] slab_free mm/slub.c:4280 [inline] kmem_cache_free+0x10b/0x2c0 mm/slub.c:4344 put_task_struct include/linux/sched/task.h:138 [inline] delayed_put_task_struct+0x125/0x2f0 kernel/exit.c:229 rcu_do_batch kernel/rcu/tree.c:2196 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471 __do_softirq+0x2c6/0x980 kernel/softirq.c:554 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541 __call_rcu_common kernel/rcu/tree.c:2734 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:2838 context_switch kernel/sched/core.c:5412 [inline] __schedule+0x179e/0x4a00 kernel/sched/core.c:6746 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6925 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6949 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] nilfs_segctor_kill_thread fs/nilfs2/segment.c:2644 [inline] nilfs_segctor_destroy fs/nilfs2/segment.c:2727 [inline] nilfs_detach_log_writer+0x262/0xbe0 fs/nilfs2/segment.c:2816 nilfs_put_super+0x4d/0x160 fs/nilfs2/super.c:499 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 deactivate_locked_super+0xc4/0x130 fs/super.c:472 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88801abf0000 which belongs to the cache task_struct of size 7424 The buggy address is located 2576 bytes inside of freed 7424-byte region [ffff88801abf0000, ffff88801abf1d00) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1abf0 head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888065b20801 anon flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffffff() raw: 00fff80000000840 ffff8880162a6500 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff888065b20801 head: 00fff80000000840 ffff8880162a6500 0000000000000000 dead000000000001 head: 0000000000000000 0000000000040004 00000001ffffffff ffff888065b20801 head: 00fff80000000003 ffffea00006afc01 ffffea00006afc48 00000000ffffffff head: 0000000800000000 0000000000000000 00000000ffffffff 0000000000000000 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 10, tgid -323831268 (kworker/u8:0), ts 10, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534 prep_new_page mm/page_alloc.c:1541 [inline] get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317 __alloc_pages+0x256/0x6c0 mm/page_alloc.c:4575 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page+0x5f/0x160 mm/slub.c:2175 allocate_slab mm/slub.c:2338 [inline] new_slab+0x84/0x2f0 mm/slub.c:2391 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525 __slab_alloc mm/slub.c:3610 [inline] __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] kmem_cache_alloc_node+0x24a/0x380 mm/slub.c:3888 alloc_task_struct_node kernel/fork.c:176 [inline] dup_task_struct+0x57/0x7d0 kernel/fork.c:1107 copy_process+0x5d1/0x3df0 kernel/fork.c:2220 kernel_clone+0x223/0x870 kernel/fork.c:2797 user_mode_thread+0x132/0x1a0 kernel/fork.c:2875 call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:172 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 page_owner free stack trace missing Memory state around the buggy address: ffff88801abf0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801abf0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801abf0a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801abf0a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801abf0b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: e8 26 97 1f 00 call 0x1f972b 5: 90 nop 6: 0f 0b ud2 8: 90 nop 9: e9 d8 f8 ff ff jmp 0xfffff8e6 e: e8 18 97 1f 00 call 0x1f972b 13: e8 93 85 00 0a call 0xa0085ab 18: 4d 85 f6 test %r14,%r14 1b: 74 b6 je 0xffffffd3 1d: e8 09 97 1f 00 call 0x1f972b 22: fb sti 23: 48 8b 44 24 70 mov 0x70(%rsp),%rax * 28: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax <-- trapping instruction 2d: 84 c0 test %al,%al 2f: 48 8b 7c 24 30 mov 0x30(%rsp),%rdi 34: 0f 85 22 02 00 00 jne 0x25c 3a: 0f b6 1f movzbl (%rdi),%ebx 3d: 31 .byte 0x31