================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x74/0x1ff0 kernel/locking/lockdep.c:4881 Read of size 8 at addr ffff88807e7727e8 by task udevd/3547 CPU: 1 PID: 3547 Comm: udevd Not tainted 5.15.132-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb 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:4881 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __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:4026 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1737 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750 __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:variable_test_bit arch/x86/include/asm/bitops.h:214 [inline] RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:135 [inline] RIP: 0010:tomoyo_check_acl+0x2f8/0x410 security/tomoyo/domain.c:184 Code: 48 89 df 48 c1 ef 03 83 e7 18 48 8b 6c 24 20 48 01 ef be 08 00 00 00 e8 46 1c 06 fe 31 f6 48 0f a3 5d 00 0f 93 c3 40 0f 92 c6 02 00 00 00 e8 3e 78 bc fd 84 db 74 19 41 0f b7 c7 3d 00 01 00 RSP: 0018:ffffc90002d9f938 EFLAGS: 00000246 RAX: ffffffff83c3a701 RBX: 0000000000000001 RCX: ffffffff83c3a76a RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888023b81ab8 RBP: ffff888023b81ab0 R08: dffffc0000000000 R09: ffffed1004770358 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000fe0 R13: dffffc0000000000 R14: ffffc90002d9fa68 R15: 0000000000000071 tomoyo_path_permission+0x1af/0x360 security/tomoyo/file.c:586 tomoyo_path_perm+0x436/0x6b0 security/tomoyo/file.c:838 security_inode_getattr+0xcf/0x120 security/security.c:1348 vfs_getattr+0x26/0x360 fs/stat.c:157 vfs_statx+0x18f/0x3b0 fs/stat.c:225 vfs_fstatat fs/stat.c:243 [inline] __do_sys_newfstatat fs/stat.c:411 [inline] __se_sys_newfstatat fs/stat.c:405 [inline] __x64_sys_newfstatat+0x12c/0x1b0 fs/stat.c:405 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f5cf0d705f4 Code: 64 c7 00 09 00 00 00 83 c8 ff c3 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 00 00 00 00 41 89 ca b8 06 01 00 00 0f 05 <45> 31 c0 3d 00 f0 ff ff 76 10 48 8b 15 03 a8 0d 00 f7 d8 41 83 c8 RSP: 002b:00007ffdbe3888a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 00007f5cf0d705f4 RDX: 00007ffdbe3888b8 RSI: 00007ffdbe388987 RDI: 00000000ffffff9c RBP: 00007ffdbe3899c0 R08: 0000000000000000 R09: 00007ffdbe389348 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdbe3899d8 R13: 0000000000000000 R14: 0000000000000008 R15: 0000557973646910 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:886 copy_process+0x5eb/0x3ef0 kernel/fork.c:2030 kernel_clone+0x210/0x960 kernel/fork.c:2596 kernel_thread+0x168/0x1e0 kernel/fork.c:2648 create_kthread kernel/kthread.c:342 [inline] kthreadd+0x57d/0x740 kernel/kthread.c:686 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Freed by task 3540: 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:2510 [inline] rcu_core+0xa15/0x1650 kernel/rcu/tree.c:2750 __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:2994 [inline] call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3074 context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12cc/0x4590 kernel/sched/core.c:6372 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6776 irqentry_exit+0x53/0x80 kernel/entry/common.c:426 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:643 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:2994 [inline] call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3074 context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12cc/0x4590 kernel/sched/core.c:6372 schedule+0x11b/0x1f0 kernel/sched/core.c:6455 nilfs_segctor_kill_thread fs/nilfs2/segment.c:2679 [inline] nilfs_segctor_destroy fs/nilfs2/segment.c:2761 [inline] nilfs_detach_log_writer+0x2e6/0xbd0 fs/nilfs2/segment.c:2850 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:175 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88807e771dc0 which belongs to the cache task_struct of size 7360 The buggy address is located 2600 bytes inside of 7360-byte region [ffff88807e771dc0, ffff88807e773a80) The buggy address belongs to the page: page:ffffea0001f9dc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e770 head:ffffea0001f9dc00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888011ddc3c0 raw: 0000000000000000 0000000000040004 00000001ffffffff 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 2944, ts 11909193435, free_ts 10846199896 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:5421 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:886 copy_process+0x5eb/0x3ef0 kernel/fork.c:2030 kernel_clone+0x210/0x960 kernel/fork.c:2596 __do_sys_clone kernel/fork.c:2713 [inline] __se_sys_clone kernel/fork.c:2697 [inline] __x64_sys_clone+0x23f/0x290 kernel/fork.c:2697 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb 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:9340 destroy_args+0xfe/0x97f mm/debug_vm_pgtable.c:1018 debug_vm_pgtable+0x40d/0x462 mm/debug_vm_pgtable.c:1331 do_one_initcall+0x22b/0x7a0 init/main.c:1295 do_initcall_level+0x157/0x207 init/main.c:1368 do_initcalls+0x49/0x86 init/main.c:1384 kernel_init_freeable+0x43c/0x5c5 init/main.c:1608 kernel_init+0x19/0x290 init/main.c:1499 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Memory state around the buggy address: ffff88807e772680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e772700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807e772780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807e772800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e772880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 48 89 df mov %rbx,%rdi 3: 48 c1 ef 03 shr $0x3,%rdi 7: 83 e7 18 and $0x18,%edi a: 48 8b 6c 24 20 mov 0x20(%rsp),%rbp f: 48 01 ef add %rbp,%rdi 12: be 08 00 00 00 mov $0x8,%esi 17: e8 46 1c 06 fe call 0xfe061c62 1c: 31 f6 xor %esi,%esi 1e: 48 0f a3 5d 00 bt %rbx,0x0(%rbp) 23: 0f 93 c3 setae %bl 26: 40 0f 92 c6 setb %sil * 2a: bf 02 00 00 00 mov $0x2,%edi <-- trapping instruction 2f: e8 3e 78 bc fd call 0xfdbc7872 34: 84 db test %bl,%bl 36: 74 19 je 0x51 38: 41 0f b7 c7 movzwl %r15w,%eax 3c: 3d .byte 0x3d 3d: 00 01 add %al,(%rcx)