====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz-executor/5841 is trying to acquire lock: ffff88806a156358 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 but task is already holding lock: ffff888035025918 (&(log)->loglock){+.+.}-{4:4}, at: jfs_umount+0x17f/0x3d0 fs/jfs/jfs_umount.c:66 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&(log)->loglock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:632 [inline] __mutex_lock+0x19e/0x1420 kernel/locking/mutex.c:794 lmLog+0x78/0xa40 fs/jfs/jfs_logmgr.c:234 diLog fs/jfs/jfs_txnmgr.c:1454 [inline] txLog fs/jfs/jfs_txnmgr.c:1406 [inline] txCommit+0x16fb/0x5410 fs/jfs/jfs_txnmgr.c:1266 jfs_commit_inode+0x2ef/0x530 fs/jfs/inode.c:114 jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138 write_inode fs/fs-writeback.c:1582 [inline] __writeback_single_inode+0x75a/0x10e0 fs/fs-writeback.c:1825 writeback_sb_inodes+0x979/0x19d0 fs/fs-writeback.c:2054 wb_writeback+0x445/0xb00 fs/fs-writeback.c:2239 wb_do_writeback fs/fs-writeback.c:2386 [inline] wb_workfn+0x3f8/0xf10 fs/fs-writeback.c:2426 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #0 (&jfs_ip->commit_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:632 [inline] __mutex_lock+0x19e/0x1420 kernel/locking/mutex.c:794 jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138 write_inode fs/fs-writeback.c:1582 [inline] __writeback_single_inode+0x75a/0x10e0 fs/fs-writeback.c:1825 writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1881 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2972 iput_final fs/inode.c:1950 [inline] iput+0x8c1/0xe80 fs/inode.c:2009 jfs_umount+0x198/0x3d0 fs/jfs/jfs_umount.c:72 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(log)->loglock); lock(&jfs_ip->commit_mutex); lock(&(log)->loglock); lock(&jfs_ip->commit_mutex); *** DEADLOCK *** 2 locks held by syz-executor/5841: #0: ffff888050f2c0d8 (&type->s_umount_key#87){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888050f2c0d8 (&type->s_umount_key#87){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888050f2c0d8 (&type->s_umount_key#87){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffff888035025918 (&(log)->loglock){+.+.}-{4:4}, at: jfs_umount+0x17f/0x3d0 fs/jfs/jfs_umount.c:66 stack backtrace: CPU: 0 UID: 0 PID: 5841 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:632 [inline] __mutex_lock+0x19e/0x1420 kernel/locking/mutex.c:794 jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138 write_inode fs/fs-writeback.c:1582 [inline] __writeback_single_inode+0x75a/0x10e0 fs/fs-writeback.c:1825 writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1881 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2972 iput_final fs/inode.c:1950 [inline] iput+0x8c1/0xe80 fs/inode.c:2009 jfs_umount+0x198/0x3d0 fs/jfs/jfs_umount.c:72 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2f0179da57 Code: a2 c7 05 9c fc 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd82ab3bb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f2f01832048 RCX: 00007f2f0179da57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd82ab3c70 RBP: 00007ffd82ab3c70 R08: 00007ffd82ab4c70 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd82ab4d00 R13: 00007f2f01832048 R14: 000000000002faa3 R15: 00007ffd82ab4d40