REISERFS (device loop4): using 3.5.x disk format REISERFS (device loop4): Created .reiserfs_priv - reserved for xattr storage. ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.1846/10168 is trying to acquire lock: ffff0000d90b6090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27 but task is already holding lock: ffff0000f7329020 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline] ffff0000f7329020 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: filename_create+0x1b0/0x3a8 fs/namei.c:3884 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}: down_write_nested+0x64/0x94 kernel/locking/rwsem.c:1689 inode_lock_nested include/linux/fs.h:793 [inline] filename_create+0x1b0/0x3a8 fs/namei.c:3884 do_mkdirat+0xac/0x3ec fs/namei.c:4129 __do_sys_mkdirat fs/namei.c:4154 [inline] __se_sys_mkdirat fs/namei.c:4152 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 -> #1 (sb_writers#26){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1891 [inline] sb_start_write+0x74/0x2ac include/linux/fs.h:1966 mnt_want_write_file+0x64/0x1e8 fs/namespace.c:446 reiserfs_ioctl+0x114/0x450 fs/reiserfs/ioctl.c:103 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 -> #0 (&sbi->lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2880/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x1f60 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27 reiserfs_lookup+0x150/0x3e0 fs/reiserfs/namei.c:364 lookup_one_qstr_excl+0x108/0x230 fs/namei.c:1613 filename_create+0x1d0/0x3a8 fs/namei.c:3885 do_mkdirat+0xac/0x3ec fs/namei.c:4129 __do_sys_mkdirat fs/namei.c:4154 [inline] __se_sys_mkdirat fs/namei.c:4152 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 other info that might help us debug this: Chain exists of: &sbi->lock --> sb_writers#26 --> &type->i_mutex_dir_key#20/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&type->i_mutex_dir_key#20/1); lock(sb_writers#26); lock(&type->i_mutex_dir_key#20/1); lock(&sbi->lock); *** DEADLOCK *** 2 locks held by syz.4.1846/10168: #0: ffff0000ca132460 (sb_writers#26){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:402 #1: ffff0000f7329020 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline] #1: ffff0000f7329020 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: filename_create+0x1b0/0x3a8 fs/namei.c:3884 stack backtrace: CPU: 1 PID: 10168 Comm: syz.4.1846 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2048 check_noncircular+0x264/0x2f8 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2880/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x1f60 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27 reiserfs_lookup+0x150/0x3e0 fs/reiserfs/namei.c:364 lookup_one_qstr_excl+0x108/0x230 fs/namei.c:1613 filename_create+0x1d0/0x3a8 fs/namei.c:3885 do_mkdirat+0xac/0x3ec fs/namei.c:4129 __do_sys_mkdirat fs/namei.c:4154 [inline] __se_sys_mkdirat fs/namei.c:4152 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585