------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 3062 at lib/refcount.c:87 refcount_dec_and_lock+0x180/0x1ec lib/refcount.c:146 Modules linked in: CPU: 0 PID: 3062 Comm: syz-executor.2 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 : ffff80001278bb20 x29: ffff80001278bb20 x28: ffff80000cc15062 x27: ffff000127822640 x26: 0000000000000002 x25: 00000000ffffffff x24: 0000000000000000 x23: 00000000c0000000 x22: 0000000000000000 x21: ffff80000d5eb4a0 x20: ffff00012e13cc20 x19: ffff80000d8c8000 x18: 00000000000000c0 x17: ffff80000dd0b198 x16: ffff80000db49158 x15: ffff0000c10a0000 x14: 0000000000000000 x13: 00000000ffffffff x12: ffff0000c10a0000 x11: ff808000081c0d5c x10: 0000000000000000 x9 : f0ea08f4834ca500 x8 : f0ea08f4834ca500 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_segctor_destroy fs/nilfs2/segment.c:2747 [inline] nilfs_detach_log_writer+0x3b8/0x4d0 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 irq event stamp: 6191888 hardirqs last enabled at (6191887): [] __up_console_sem+0xb0/0xfc kernel/printk/printk.c:264 hardirqs last disabled at (6191888): [] el1_dbg+0x24/0x5c arch/arm64/kernel/entry-common.c:404 softirqs last enabled at (6191882): [] _stext+0x2e4/0x37c softirqs last disabled at (6191855): [] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79 ---[ end trace 0000000000000000 ]--- EXT4-fs (loop2): unmounting filesystem. EXT4-fs (loop2): unmounting filesystem. EXT4-fs (loop2): unmounting filesystem.