================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x77/0x1f80 kernel/locking/lockdep.c:4919 Read of size 8 at addr ffff888017f88a18 by task syz-executor.3/12408 CPU: 1 PID: 12408 Comm: syz-executor.3 Not tainted 6.1.87-syzkaller #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+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 __lock_acquire+0x77/0x1f80 kernel/locking/lockdep.c:4919 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __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+0xad/0x12e0 kernel/sched/core.c:4112 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:__kmem_cache_alloc_node+0x1/0x260 mm/slub.c:3436 Code: fe ff ff 8b 45 28 49 01 c7 ba 08 00 00 00 4c 89 ff 31 f6 e8 51 4e a7 08 e9 03 fe ff ff 0f 0b 0f 0b 0f 0b e9 31 ff ff ff 90 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 28 4d 89 c7 48 89 cd 41 89 d5 RSP: 0018:ffffc900031df880 EFLAGS: 00000296 RAX: 0000000000000000 RBX: 0000000000000046 RCX: 0000000000000046 RDX: 00000000ffffffff RSI: 0000000000000d40 RDI: ffff888012441780 RBP: ffff888012441780 R08: ffffffff83f3c3cb R09: fffffbfff1ce6eee R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888027d96ffc R13: 0000000000000d40 R14: ffffffff83f3c3cb R15: 0000000000000000 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc+0xa1/0x230 mm/slab_common.c:968 kmalloc include/linux/slab.h:561 [inline] kzalloc include/linux/slab.h:692 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x26b/0x530 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x594/0x5d0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x29f/0x710 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x120 security/security.c:1361 vfs_getattr+0x26/0x360 fs/stat.c:158 vfs_statx+0x194/0x4b0 fs/stat.c:233 vfs_fstatat fs/stat.c:267 [inline] __do_sys_newfstatat fs/stat.c:437 [inline] __se_sys_newfstatat fs/stat.c:431 [inline] __x64_sys_newfstatat+0x151/0x1e0 fs/stat.c:431 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f20f4c7c94a Code: 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 0b 00 00 00 66 2e 0f 1f 84 00 00 00 00 00 90 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 c7 c2 b0 ff ff ff f7 RSP: 002b:00007ffcc593b0a8 EFLAGS: 00000286 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f20f4c7c94a RDX: 00007ffcc593b0d0 RSI: 00007ffcc593b160 RDI: 00000000ffffff9c RBP: 00007ffcc593b160 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000286 R12: 00007ffcc593c220 R13: 00007f20f4cc93b9 R14: 000000000006e95e R15: 0000000000000002 Allocated by task 2: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] kmem_cache_alloc_node+0x136/0x310 mm/slub.c:3443 alloc_task_struct_node kernel/fork.c:171 [inline] dup_task_struct+0x57/0x6d0 kernel/fork.c:980 copy_process+0x637/0x4060 kernel/fork.c:2098 kernel_clone+0x222/0x920 kernel/fork.c:2682 kernel_thread+0x152/0x1d0 kernel/fork.c:2742 create_kthread kernel/kthread.c:399 [inline] kthreadd+0x596/0x760 kernel/kthread.c:746 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Freed by task 21: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] kmem_cache_free+0x292/0x510 mm/slub.c:3683 rcu_do_batch kernel/rcu/tree.c:2296 [inline] rcu_core+0xad5/0x1810 kernel/rcu/tree.c:2556 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 call_rcu+0x163/0xa10 kernel/rcu/tree.c:2844 context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1435/0x4550 kernel/sched/core.c:6558 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] nilfs_segctor_kill_thread fs/nilfs2/segment.c:2678 [inline] nilfs_segctor_destroy fs/nilfs2/segment.c:2761 [inline] nilfs_detach_log_writer+0x25e/0xbd0 fs/nilfs2/segment.c:2850 nilfs_put_super+0x49/0x150 fs/nilfs2/super.c:498 generic_shutdown_super+0x130/0x340 fs/super.c:501 kill_block_super+0x7a/0xe0 fs/super.c:1459 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 call_rcu+0x163/0xa10 kernel/rcu/tree.c:2844 release_task+0x1637/0x16d0 wait_task_zombie kernel/exit.c:1205 [inline] wait_consider_task+0x1a64/0x2e90 kernel/exit.c:1432 do_wait_thread kernel/exit.c:1495 [inline] do_wait+0x32b/0xb80 kernel/exit.c:1612 kernel_wait4+0x29e/0x3e0 kernel/exit.c:1775 __do_sys_wait4 kernel/exit.c:1803 [inline] __se_sys_wait4 kernel/exit.c:1799 [inline] __x64_sys_wait4+0x130/0x1e0 kernel/exit.c:1799 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888017f88000 which belongs to the cache task_struct of size 7360 The buggy address is located 2584 bytes inside of 7360-byte region [ffff888017f88000, ffff888017f89cc0) The buggy address belongs to the physical page: page:ffffea00005fe200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x17f88 head:ffffea00005fe200 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff8880746e18c1 flags: 0xfff80000010200(slab|head|node=0|zone=1|lastcpupid=0xfff) raw: 00fff80000010200 dead000000000100 dead000000000122 ffff888140008500 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff8880746e18c1 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, tgid 2 (kthreadd), ts 6348419588, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513 prep_new_page mm/page_alloc.c:2520 [inline] get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5547 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x2d0 mm/slub.c:1992 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] kmem_cache_alloc_node+0x1cf/0x310 mm/slub.c:3443 alloc_task_struct_node kernel/fork.c:171 [inline] dup_task_struct+0x57/0x6d0 kernel/fork.c:980 copy_process+0x637/0x4060 kernel/fork.c:2098 kernel_clone+0x222/0x920 kernel/fork.c:2682 kernel_thread+0x152/0x1d0 kernel/fork.c:2742 create_kthread kernel/kthread.c:399 [inline] kthreadd+0x596/0x760 kernel/kthread.c:746 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 page_owner free stack trace missing Memory state around the buggy address: ffff888017f88900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888017f88980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888017f88a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888017f88a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888017f88b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 3 bytes skipped: 0: 8b 45 28 mov 0x28(%rbp),%eax 3: 49 01 c7 add %rax,%r15 6: ba 08 00 00 00 mov $0x8,%edx b: 4c 89 ff mov %r15,%rdi e: 31 f6 xor %esi,%esi 10: e8 51 4e a7 08 call 0x8a74e66 15: e9 03 fe ff ff jmp 0xfffffe1d 1a: 0f 0b ud2 1c: 0f 0b ud2 1e: 0f 0b ud2 20: e9 31 ff ff ff jmp 0xffffff56 25: 90 nop 26: 55 push %rbp * 27: 41 57 push %r15 <-- trapping instruction 29: 41 56 push %r14 2b: 41 55 push %r13 2d: 41 54 push %r12 2f: 53 push %rbx 30: 48 83 ec 28 sub $0x28,%rsp 34: 4d 89 c7 mov %r8,%r15 37: 48 89 cd mov %rcx,%rbp 3a: 41 89 d5 mov %edx,%r13d