------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 3069 at lib/refcount.c:87 refcount_dec_and_lock+0x180/0x1ec lib/refcount.c:146 Modules linked in: CPU: 0 PID: 3069 Comm: syz-executor.4 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_dec_and_lock+0x180/0x1ec lib/refcount.c:146 lr : refcount_dec_not_one lib/refcount.c:87 [inline] lr : refcount_dec_and_lock+0x17c/0x1ec lib/refcount.c:146 sp : ffff800012a23ae0 x29: ffff800012a23ae0 x28: ffff0001147b9a00 x27: ffff0001125bc470 x26: ffff0000c5341a80 x25: 00000000ffffffff x24: 0000000000000000 x23: 00000000c0000000 x22: 0000000000000000 x21: ffff80000d5eb4a0 x20: ffff000120c64c20 x19: ffff80000d8c8000 x18: 00000000000000c0 x17: ffff80000dd0b198 x16: ffff80000db49158 x15: ffff0000c5341a80 x14: 0000000000000000 x13: 00000000ffffffff x12: ffff0000c5341a80 x11: ff808000081c0d5c x10: 0000000000000000 x9 : 59581df6a4a11d00 x8 : 59581df6a4a11d00 x7 : ffff80000819545c x6 : 0000000000000000 x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000100000000 x0 : 0000000000000000 Call trace: refcount_dec_and_lock+0x180/0x1ec lib/refcount.c:146 nilfs_put_root+0x30/0x80 fs/nilfs2/the_nilfs.c:797 nilfs_clear_inode+0x108/0x140 fs/nilfs2/inode.c:895 nilfs_evict_inode+0x68/0x1cc fs/nilfs2/inode.c:908 evict+0xec/0x334 fs/inode.c:665 dispose_list fs/inode.c:698 [inline] evict_inodes+0x2e0/0x354 fs/inode.c:748 generic_shutdown_super+0x50/0x190 fs/super.c:480 kill_block_super+0x30/0x78 fs/super.c:1427 deactivate_locked_super+0x70/0xe8 fs/super.c:332 deactivate_super+0xd0/0xd4 fs/super.c:363 cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0xc4/0x14c kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 irq event stamp: 4590060 hardirqs last enabled at (4590059): [] __up_console_sem+0xb0/0xfc kernel/printk/printk.c:264 hardirqs last disabled at (4590060): [] el1_dbg+0x24/0x5c arch/arm64/kernel/entry-common.c:404 softirqs last enabled at (4589450): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (4589448): [] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19 ---[ end trace 0000000000000000 ]--- ============================= WARNING: suspicious RCU usage 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Tainted: G W ----------------------------- kernel/sched/core.c:9854 Illegal context switch in RCU-bh read-side critical section! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz-executor.4/3069: #0: ffff0001147b90e0 (&type->s_umount_key#84){++++}-{3:3}, at: deactivate_super+0xc8/0xd4 fs/super.c:362 stack backtrace: CPU: 0 PID: 3069 Comm: syz-executor.4 Tainted: G W 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x138/0x154 kernel/locking/lockdep.c:6595 __might_resched+0x6c/0x218 kernel/sched/core.c:9854 __might_sleep+0x48/0x78 kernel/sched/core.c:9821 do_page_fault+0x214/0x79c arch/arm64/mm/fault.c:593 do_translation_fault+0x78/0x194 arch/arm64/mm/fault.c:685 do_mem_abort+0x54/0x130 arch/arm64/mm/fault.c:821 el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:366 el1h_64_sync_handler+0x60/0xac arch/arm64/kernel/entry-common.c:426 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:576 __lock_acquire+0x60/0x30a4 kernel/locking/lockdep.c:4923 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 down_write+0x5c/0xcc kernel/locking/rwsem.c:1552 nilfs_bmap_test_and_clear_dirty+0x28/0x58 fs/nilfs2/bmap.c:431 nilfs_mdt_fetch_dirty+0x24/0x94 fs/nilfs2/mdt.c:394 nilfs_test_metadata_dirty+0x2c/0x148 fs/nilfs2/segment.c:813 nilfs_segctor_confirm+0x30/0x1a8 fs/nilfs2/segment.c:837 nilfs_segctor_destroy fs/nilfs2/segment.c:2729 [inline] nilfs_detach_log_writer+0x1f0/0x4d0 fs/nilfs2/segment.c:2810 nilfs_put_super+0x28/0x9c fs/nilfs2/super.c:468 generic_shutdown_super+0x8c/0x190 fs/super.c:491 kill_block_super+0x30/0x78 fs/super.c:1427 deactivate_locked_super+0x70/0xe8 fs/super.c:332 deactivate_super+0xd0/0xd4 fs/super.c:363 cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0xc4/0x14c kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 ============================= WARNING: suspicious RCU usage 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Tainted: G W ----------------------------- kernel/sched/core.c:9854 Illegal context switch in RCU-sched read-side critical section! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz-executor.4/3069: #0: ffff0001147b90e0 (&type->s_umount_key#84){++++}-{3:3}, at: deactivate_super+0xc8/0xd4 fs/super.c:362 stack backtrace: CPU: 0 PID: 3069 Comm: syz-executor.4 Tainted: G W 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x138/0x154 kernel/locking/lockdep.c:6595 __might_resched+0xb4/0x218 kernel/sched/core.c:9854 __might_sleep+0x48/0x78 kernel/sched/core.c:9821 do_page_fault+0x214/0x79c arch/arm64/mm/fault.c:593 do_translation_fault+0x78/0x194 arch/arm64/mm/fault.c:685 do_mem_abort+0x54/0x130 arch/arm64/mm/fault.c:821 el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:366 el1h_64_sync_handler+0x60/0xac arch/arm64/kernel/entry-common.c:426 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:576 __lock_acquire+0x60/0x30a4 kernel/locking/lockdep.c:4923 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 down_write+0x5c/0xcc kernel/locking/rwsem.c:1552 nilfs_bmap_test_and_clear_dirty+0x28/0x58 fs/nilfs2/bmap.c:431 nilfs_mdt_fetch_dirty+0x24/0x94 fs/nilfs2/mdt.c:394 nilfs_test_metadata_dirty+0x2c/0x148 fs/nilfs2/segment.c:813 nilfs_segctor_confirm+0x30/0x1a8 fs/nilfs2/segment.c:837 nilfs_segctor_destroy fs/nilfs2/segment.c:2729 [inline] nilfs_detach_log_writer+0x1f0/0x4d0 fs/nilfs2/segment.c:2810 nilfs_put_super+0x28/0x9c fs/nilfs2/super.c:468 generic_shutdown_super+0x8c/0x190 fs/super.c:491 kill_block_super+0x30/0x78 fs/super.c:1427 deactivate_locked_super+0x70/0xe8 fs/super.c:332 deactivate_super+0xd0/0xd4 fs/super.c:363 cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0xc4/0x14c kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 BUG: sleeping function called from invalid context at arch/arm64/mm/fault.c:593 in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 3069, name: syz-executor.4 preempt_count: 0, expected: 0 RCU nest depth: 0, expected: 0 1 lock held by syz-executor.4/3069: #0: ffff0001147b90e0 (&type->s_umount_key#84){++++}-{3:3}, at: deactivate_super+0xc8/0xd4 fs/super.c:362 irq event stamp: 4590259 hardirqs last enabled at (4590259): [] call_rcu+0x2f0/0x484 kernel/rcu/tree.c:2828 hardirqs last disabled at (4590258): [] call_rcu+0x28c/0x484 kernel/rcu/tree.c:2794 softirqs last enabled at (4590218): [] _stext+0x2e4/0x37c softirqs last disabled at (4590065): [] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79 CPU: 0 PID: 3069 Comm: syz-executor.4 Tainted: G W 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 __might_resched+0x208/0x218 kernel/sched/core.c:9892 __might_sleep+0x48/0x78 kernel/sched/core.c:9821 do_page_fault+0x214/0x79c arch/arm64/mm/fault.c:593 do_translation_fault+0x78/0x194 arch/arm64/mm/fault.c:685 do_mem_abort+0x54/0x130 arch/arm64/mm/fault.c:821 el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:366 el1h_64_sync_handler+0x60/0xac arch/arm64/kernel/entry-common.c:426 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:576 __lock_acquire+0x60/0x30a4 kernel/locking/lockdep.c:4923 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 down_write+0x5c/0xcc kernel/locking/rwsem.c:1552 nilfs_bmap_test_and_clear_dirty+0x28/0x58 fs/nilfs2/bmap.c:431 nilfs_mdt_fetch_dirty+0x24/0x94 fs/nilfs2/mdt.c:394 nilfs_test_metadata_dirty+0x2c/0x148 fs/nilfs2/segment.c:813 nilfs_segctor_confirm+0x30/0x1a8 fs/nilfs2/segment.c:837 nilfs_segctor_destroy fs/nilfs2/segment.c:2729 [inline] nilfs_detach_log_writer+0x1f0/0x4d0 fs/nilfs2/segment.c:2810 nilfs_put_super+0x28/0x9c fs/nilfs2/super.c:468 generic_shutdown_super+0x8c/0x190 fs/super.c:491 kill_block_super+0x30/0x78 fs/super.c:1427 deactivate_locked_super+0x70/0xe8 fs/super.c:332 deactivate_super+0xd0/0xd4 fs/super.c:363 cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0xc4/0x14c kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a8 Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=000000014e641000 [00000000000000a8] pgd=08000001530d7003, p4d=08000001530d7003, pud=0000000000000000 Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 3069 Comm: syz-executor.4 Tainted: G W 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __lock_acquire+0x60/0x30a4 kernel/locking/lockdep.c:4923 lr : lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 sp : ffff800012a238d0 x29: ffff800012a239b0 x28: 0000000000000000 x27: 0000000000000000 x26: 00000000000000a8 x25: ffff800008f597f8 x24: 0000000000000000 x23: 0000000000000000 x22: 00000000000000a8 x21: 0000000000000000 x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000002 x17: ffff80000bffd6bc x16: ffff80000db49158 x15: ffff0000c5341a80 x14: 0000000000000000 x13: 00000000ffffffff x12: ffff0000c5341a80 x11: ff808000095d1a0c x10: 0000000000000000 x9 : 0000000000000001 x8 : 0000000000000001 x7 : ffff800008f597f8 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 00000000000000a8 Call trace: __lock_acquire+0x60/0x30a4 kernel/locking/lockdep.c:4923 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 down_write+0x5c/0xcc kernel/locking/rwsem.c:1552 nilfs_bmap_test_and_clear_dirty+0x28/0x58 fs/nilfs2/bmap.c:431 nilfs_mdt_fetch_dirty+0x24/0x94 fs/nilfs2/mdt.c:394 nilfs_test_metadata_dirty+0x2c/0x148 fs/nilfs2/segment.c:813 nilfs_segctor_confirm+0x30/0x1a8 fs/nilfs2/segment.c:837 nilfs_segctor_destroy fs/nilfs2/segment.c:2729 [inline] nilfs_detach_log_writer+0x1f0/0x4d0 fs/nilfs2/segment.c:2810 nilfs_put_super+0x28/0x9c fs/nilfs2/super.c:468 generic_shutdown_super+0x8c/0x190 fs/super.c:491 kill_block_super+0x30/0x78 fs/super.c:1427 deactivate_locked_super+0x70/0xe8 fs/super.c:332 deactivate_super+0xd0/0xd4 fs/super.c:363 cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0xc4/0x14c kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 Code: 2a0303f4 2a0203f7 aa0003fa 34000148 (f9400348) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 2a0303f4 mov w20, w3 4: 2a0203f7 mov w23, w2 8: aa0003fa mov x26, x0 c: 34000148 cbz w8, 0x34 * 10: f9400348 ldr x8, [x26] <-- trapping instruction