====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz-executor/21342 is trying to acquire lock: ffff8880555f9378 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 but task is already holding lock: ffff888064578918 (&(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:646 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820 lmLog+0x78/0xa40 fs/jfs/jfs_logmgr.c:234 xtLog fs/jfs/jfs_txnmgr.c:1801 [inline] txLog fs/jfs/jfs_txnmgr.c:1398 [inline] txCommit+0x244e/0x5410 fs/jfs/jfs_txnmgr.c:1266 jfs_truncate_nolock+0x22f/0x340 fs/jfs/inode.c:407 jfs_truncate fs/jfs/inode.c:420 [inline] jfs_write_failed fs/jfs/inode.c:295 [inline] jfs_write_end+0x16f/0x1f0 fs/jfs/inode.c:322 generic_perform_write+0x620/0x8f0 mm/filemap.c:4346 generic_file_write_iter+0x14a/0x680 mm/filemap.c:4468 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61d/0xb90 fs/read_write.c:688 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #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:646 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820 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:1584 [inline] __writeback_single_inode+0x75a/0x10e0 fs/fs-writeback.c:1827 writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1883 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2974 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+0xf3/0x4d0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [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/21342: #0: ffff888076a140d8 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888076a140d8 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888076a140d8 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffff888064578918 (&(log)->loglock){+.+.}-{4:4}, at: jfs_umount+0x17f/0x3d0 fs/jfs/jfs_umount.c:66 stack backtrace: CPU: 0 UID: 0 PID: 21342 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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:646 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820 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:1584 [inline] __writeback_single_inode+0x75a/0x10e0 fs/fs-writeback.c:1827 writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1883 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2974 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+0xf3/0x4d0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9e20d9e017 Code: a2 c7 05 dc 06 25 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:00007ffc75a113d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f9e20e32120 RCX: 00007f9e20d9e017 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc75a11490 RBP: 00007ffc75a11490 R08: 00007ffc75a12490 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc75a12520 R13: 00007f9e20e32120 R14: 000000000019530f R15: 00007ffc75a12560