================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x78/0x1fd0 kernel/locking/lockdep.c:5005 Read of size 8 at addr ffff88805b506410 by task syz-executor.4/8843 CPU: 0 PID: 8843 Comm: syz-executor.4 Not tainted 6.9.0-rc7-syzkaller-00183-gcf87f46fd34d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 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 handle_softirqs+0x2d6/0x990 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 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 a6 94 1f 00 90 0f 0b 90 e9 d8 f8 ff ff e8 98 94 1f 00 e8 73 1d 01 0a 4d 85 f6 74 b6 e8 89 94 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:ffffc90009a47200 EFLAGS: 00000287 RAX: 1ffff92001348e8c RBX: 0000000000000000 RCX: 0000000000040000 RDX: ffffc90010456000 RSI: 0000000000018059 RDI: 000000000001805a RBP: ffffc90009a473b0 R08: ffffffff817672a4 R09: 1ffffffff25dfca0 R10: dffffc0000000000 R11: fffffbfff25dfca1 R12: ffffffff8eb038b8 R13: ffffffff8eb03860 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 _btrfs_printk+0x59c/0x5c0 fs/btrfs/messages.c:246 btrfs_check_options+0x410/0x4d0 fs/btrfs/super.c:666 open_ctree+0x10ed/0x2a00 fs/btrfs/disk-io.c:3324 btrfs_fill_super fs/btrfs/super.c:938 [inline] btrfs_get_tree_super fs/btrfs/super.c:1858 [inline] btrfs_get_tree+0xe7a/0x1920 fs/btrfs/super.c:2084 vfs_get_tree+0x90/0x2a0 fs/super.c:1779 fc_mount+0x1b/0xb0 fs/namespace.c:1125 btrfs_get_tree_subvol fs/btrfs/super.c:2047 [inline] btrfs_get_tree+0x652/0x1920 fs/btrfs/super.c:2085 vfs_get_tree+0x90/0x2a0 fs/super.c:1779 do_new_mount+0x2be/0xb40 fs/namespace.c:3352 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f642207f46a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6422e3eef8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f6422e3ef80 RCX: 00007f642207f46a RDX: 0000000020000280 RSI: 0000000020000000 RDI: 00007f6422e3ef40 RBP: 0000000020000280 R08: 00007f6422e3ef80 R09: 0000000000000016 R10: 0000000000000016 R11: 0000000000000202 R12: 0000000020000000 R13: 00007f6422e3ef40 R14: 00000000000050f6 R15: 00000000200054c0 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:3804 [inline] slab_alloc_node mm/slub.c:3851 [inline] kmem_cache_alloc_node+0x194/0x390 mm/slub.c:3894 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 50: 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:2111 [inline] slab_free mm/slub.c:4286 [inline] kmem_cache_free+0x10b/0x2d0 mm/slub.c:4350 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 handle_softirqs+0x2d6/0x990 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_purge_orig_ref+0x150a/0x1600 net/batman-adv/originator.c:1287 batadv_purge_orig+0x19/0x60 net/batman-adv/originator.c:1300 process_one_work kernel/workqueue.c:3267 [inline] process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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_irq+0xfb/0x1c0 kernel/sched/core.c:7068 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 The buggy address belongs to the object at ffff88805b505a00 which belongs to the cache task_struct of size 7424 The buggy address is located 2576 bytes inside of freed 7424-byte region [ffff88805b505a00, ffff88805b507700) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5b500 head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888023129881 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888015eea500 ffffea0001de1c00 dead000000000002 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff888023129881 head: 00fff00000000840 ffff888015eea500 ffffea0001de1c00 dead000000000002 head: 0000000000000000 0000000000040004 00000001ffffffff ffff888023129881 head: 00fff00000000003 ffffea00016d4001 dead000000000122 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 2, tgid 2 (kthreadd), ts 117178906239, free_ts 103801230175 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:2180 allocate_slab mm/slub.c:2343 [inline] new_slab+0x84/0x2f0 mm/slub.c:2396 ___slab_alloc+0xc73/0x1260 mm/slub.c:3530 __slab_alloc mm/slub.c:3615 [inline] __slab_alloc_node mm/slub.c:3668 [inline] slab_alloc_node mm/slub.c:3841 [inline] kmem_cache_alloc_node+0x24a/0x390 mm/slub.c:3894 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 page last free pid 5099 tgid 5099 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] __free_pages_ok+0xc54/0xd80 mm/page_alloc.c:1270 __folio_put_large+0x168/0x1d0 mm/swap.c:132 __folio_put+0x299/0x390 mm/swap.c:140 folio_put include/linux/mm.h:1508 [inline] free_large_kmalloc+0x105/0x1c0 mm/slub.c:4367 kfree+0x1ca/0x3b0 mm/slub.c:4390 __bch2_fs_free fs/bcachefs/super.c:602 [inline] bch2_fs_release+0x52e/0x5a0 fs/bcachefs/super.c:610 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22f/0x480 lib/kobject.c:737 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 Memory state around the buggy address: ffff88805b506300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805b506380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805b506400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805b506480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805b506500: 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 a6 94 1f 00 call 0x1f94ab 5: 90 nop 6: 0f 0b ud2 8: 90 nop 9: e9 d8 f8 ff ff jmp 0xfffff8e6 e: e8 98 94 1f 00 call 0x1f94ab 13: e8 73 1d 01 0a call 0xa011d8b 18: 4d 85 f6 test %r14,%r14 1b: 74 b6 je 0xffffffd3 1d: e8 89 94 1f 00 call 0x1f94ab 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