================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x77/0x2070 kernel/locking/lockdep.c:4956 Read of size 8 at addr ffff888027bd0a00 by task syz-executor886/7382 CPU: 0 PID: 7382 Comm: syz-executor886 Not tainted 6.4.0-rc5-syzkaller-00245-g64569520920a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:351 [inline] print_report+0x163/0x540 mm/kasan/report.c:462 kasan_report+0x176/0x1b0 mm/kasan/report.c:572 __lock_acquire+0x77/0x2070 kernel/locking/lockdep.c:4956 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5705 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xb2/0x1230 kernel/sched/core.c:4191 call_timer_fn+0x178/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x64f/0x860 kernel/time/timer.c:2022 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035 __do_softirq+0x2ab/0x908 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x159/0x240 kernel/softirq.c:650 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:console_flush_all+0x8a7/0xd70 Code: cd f9 ff ff e8 7a b3 1c 00 0f 0b e9 87 fa ff ff e8 6e b3 1c 00 e8 d9 d2 40 09 4d 85 f6 74 c6 e8 5f b3 1c 00 fb 4c 8b 74 24 68 <48> 8b 44 24 70 42 0f b6 04 20 84 c0 0f 85 16 02 00 00 48 8b 44 24 RSP: 0018:ffffc9000c47f3a0 EFLAGS: 00000293 RAX: ffffffff816ecc41 RBX: 0000000000000000 RCX: ffff88802d4d3b80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000c47f550 R08: ffffffff816ecbee R09: fffffbfff206544d R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 0000000000000001 R14: ffffffff8d655618 R15: ffffffff8d6555c0 console_unlock+0xff/0x270 kernel/printk/printk.c:3007 vprintk_emit+0xd5/0x1f0 kernel/printk/printk.c:2307 _printk+0xd5/0x120 kernel/printk/printk.c:2328 __nilfs_msg+0x34d/0x410 fs/nilfs2/super.c:78 load_nilfs+0x893/0x1050 nilfs_fill_super+0x2b5/0x600 fs/nilfs2/super.c:1069 nilfs_mount+0x67d/0x9a0 fs/nilfs2/super.c:1326 legacy_get_tree+0xef/0x190 fs/fs_context.c:610 vfs_get_tree+0x8c/0x270 fs/super.c:1510 do_new_mount+0x28f/0xae0 fs/namespace.c:3039 do_mount fs/namespace.c:3382 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f46c23e9eda Code: 48 c7 c2 c0 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 a8 00 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdd889e678 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f46c23e9eda RDX: 0000000020000dc0 RSI: 0000000020000100 RDI: 00007ffdd889e690 RBP: 00007ffdd889e690 R08: 00007ffdd889e6d0 R09: 0000000000000da0 R10: 0000000000010018 R11: 0000000000000286 R12: 0000000000000004 R13: 0000555556cac2c0 R14: 0000000000010018 R15: 00007ffdd889e6d0 Allocated by task 2: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x66/0x70 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook+0x68/0x3a0 mm/slab.h:711 slab_alloc_node mm/slub.c:3451 [inline] kmem_cache_alloc_node+0x157/0x350 mm/slub.c:3496 alloc_task_struct_node kernel/fork.c:173 [inline] dup_task_struct+0x57/0x7d0 kernel/fork.c:1108 copy_process+0x5c8/0x4290 kernel/fork.c:2333 kernel_clone+0x222/0x800 kernel/fork.c:2915 kernel_thread+0x1bc/0x230 kernel/fork.c:2977 create_kthread kernel/kthread.c:402 [inline] kthreadd+0x600/0x820 kernel/kthread.c:737 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:491 __call_rcu_common kernel/rcu/tree.c:2627 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:2741 context_switch kernel/sched/core.c:5346 [inline] __schedule+0x1883/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 nilfs_segctor_kill_thread fs/nilfs2/segment.c:2667 [inline] nilfs_segctor_destroy fs/nilfs2/segment.c:2749 [inline] nilfs_detach_log_writer+0x2ea/0xbb0 fs/nilfs2/segment.c:2838 nilfs_put_super+0x4d/0x160 fs/nilfs2/super.c:477 generic_shutdown_super+0x134/0x340 fs/super.c:500 kill_block_super+0x84/0xf0 fs/super.c:1407 deactivate_locked_super+0xa4/0x110 fs/super.c:331 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1177 task_work_run+0x24a/0x300 kernel/task_work.c:179 ptrace_notify+0x2cd/0x380 kernel/signal.c:2371 ptrace_report_syscall include/linux/ptrace.h:411 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline] syscall_exit_work kernel/entry/common.c:252 [inline] syscall_exit_to_user_mode_prepare kernel/entry/common.c:279 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:284 [inline] syscall_exit_to_user_mode+0x157/0x280 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:491 __call_rcu_common kernel/rcu/tree.c:2627 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:2741 put_task_struct_rcu_user kernel/exit.c:232 [inline] release_task+0x15ad/0x16f0 kernel/exit.c:282 wait_task_zombie kernel/exit.c:1210 [inline] wait_consider_task+0x1a43/0x2e20 kernel/exit.c:1437 do_wait_thread kernel/exit.c:1500 [inline] do_wait+0x312/0xb00 kernel/exit.c:1617 kernel_wait4+0x2a2/0x3e0 kernel/exit.c:1780 __do_sys_wait4 kernel/exit.c:1808 [inline] __se_sys_wait4 kernel/exit.c:1804 [inline] __x64_sys_wait4+0x134/0x1e0 kernel/exit.c:1804 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888027bd0000 which belongs to the cache task_struct of size 7360 The buggy address is located 2560 bytes inside of freed 7360-byte region [ffff888027bd0000, ffff888027bd1cc0) The buggy address belongs to the physical page: page:ffffea00009ef400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888027bd0000 pfn:0x27bd0 head:ffffea00009ef400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000010200 ffff888140007500 0000000000000000 dead000000000001 raw: ffff888027bd0000 0000000080040003 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 47, tgid 47 (kworker/u4:3), ts 9536795505, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1731 prep_new_page mm/page_alloc.c:1738 [inline] get_page_from_freelist+0x321c/0x33a0 mm/page_alloc.c:3502 __alloc_pages+0x255/0x670 mm/page_alloc.c:4768 alloc_slab_page+0x6a/0x160 mm/slub.c:1851 allocate_slab mm/slub.c:1998 [inline] new_slab+0x84/0x2f0 mm/slub.c:2051 ___slab_alloc+0xa85/0x10a0 mm/slub.c:3192 __slab_alloc mm/slub.c:3291 [inline] __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] kmem_cache_alloc_node+0x1f3/0x350 mm/slub.c:3496 alloc_task_struct_node kernel/fork.c:173 [inline] dup_task_struct+0x57/0x7d0 kernel/fork.c:1108 copy_process+0x5c8/0x4290 kernel/fork.c:2333 kernel_clone+0x222/0x800 kernel/fork.c:2915 user_mode_thread+0x132/0x190 kernel/fork.c:2993 call_usermodehelper_exec_work+0x5c/0x220 kernel/umh.c:172 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 page_owner free stack trace missing Memory state around the buggy address: ffff888027bd0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888027bd0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888027bd0a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888027bd0a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888027bd0b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 4 bytes skipped: 0: e8 7a b3 1c 00 callq 0x1cb37f 5: 0f 0b ud2 7: e9 87 fa ff ff jmpq 0xfffffa93 c: e8 6e b3 1c 00 callq 0x1cb37f 11: e8 d9 d2 40 09 callq 0x940d2ef 16: 4d 85 f6 test %r14,%r14 19: 74 c6 je 0xffffffe1 1b: e8 5f b3 1c 00 callq 0x1cb37f 20: fb sti 21: 4c 8b 74 24 68 mov 0x68(%rsp),%r14 * 26: 48 8b 44 24 70 mov 0x70(%rsp),%rax <-- trapping instruction 2b: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax 30: 84 c0 test %al,%al 32: 0f 85 16 02 00 00 jne 0x24e 38: 48 rex.W 39: 8b .byte 0x8b 3a: 44 rex.R 3b: 24 .byte 0x24