====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz-executor/5628 is trying to acquire lock: ffff888048423fd8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1f5/0x4b0 fs/jfs/inode.c:108 but task is already holding lock: ffff8880534b4918 (&(log)->loglock){+.+.}-{4:4}, at: jfs_umount+0x189/0x430 fs/jfs/jfs_umount.c:66 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&(log)->loglock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1b10 kernel/locking/mutex.c:820 lmLog+0x8c/0xb90 fs/jfs/jfs_logmgr.c:234 dtLog fs/jfs/jfs_txnmgr.c:1620 [inline] txLog fs/jfs/jfs_txnmgr.c:1402 [inline] txCommit+0x326d/0x4a90 fs/jfs/jfs_txnmgr.c:1266 jfs_unlink+0x7db/0xa20 fs/jfs/namei.c:557 vfs_unlink+0x2f0/0xbd0 fs/namei.c:5498 filename_unlinkat+0x408/0x730 fs/namei.c:5568 __do_sys_unlink fs/namei.c:5603 [inline] __se_sys_unlink fs/namei.c:5600 [inline] __x64_sys_unlink+0x46/0x70 fs/namei.c:5600 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&jfs_ip->commit_mutex/1){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1b10 kernel/locking/mutex.c:820 jfs_unlink+0x2c7/0xa20 fs/jfs/namei.c:494 vfs_unlink+0x2f0/0xbd0 fs/namei.c:5498 filename_unlinkat+0x408/0x730 fs/namei.c:5568 __do_sys_unlink fs/namei.c:5603 [inline] __se_sys_unlink fs/namei.c:5600 [inline] __x64_sys_unlink+0x46/0x70 fs/namei.c:5600 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/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+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1b10 kernel/locking/mutex.c:820 jfs_commit_inode+0x1f5/0x4b0 fs/jfs/inode.c:108 jfs_write_inode+0xfb/0x230 fs/jfs/inode.c:138 write_inode fs/fs-writeback.c:1584 [inline] __writeback_single_inode+0xcd4/0x1350 fs/fs-writeback.c:1827 writeback_single_inode+0x4d3/0xf30 fs/fs-writeback.c:1883 write_inode_now+0x174/0x1f0 fs/fs-writeback.c:2974 iput_final fs/inode.c:1950 [inline] iput.part.0+0x7f3/0xf50 fs/inode.c:2009 iput+0x35/0x40 fs/inode.c:1975 diFreeSpecial+0x76/0x100 fs/jfs/jfs_imap.c:552 jfs_umount+0x1a2/0x430 fs/jfs/jfs_umount.c:72 jfs_put_super+0x88/0x1a0 fs/jfs/super.c:194 generic_shutdown_super+0x167/0x360 fs/super.c:646 kill_block_super+0x3b/0xa0 fs/super.c:1725 deactivate_locked_super+0xc1/0x1b0 fs/super.c:476 deactivate_super fs/super.c:509 [inline] deactivate_super+0xe7/0x110 fs/super.c:505 cleanup_mnt+0x21f/0x450 fs/namespace.c:1312 task_work_run+0x150/0x240 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+0x107/0x4f0 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+0x706/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &jfs_ip->commit_mutex --> &jfs_ip->commit_mutex/1 --> &(log)->loglock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(log)->loglock); lock(&jfs_ip->commit_mutex/1); lock(&(log)->loglock); lock(&jfs_ip->commit_mutex); *** DEADLOCK *** 2 locks held by syz-executor/5628: #0: ffff8880268020d8 (&type->s_umount_key#86){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880268020d8 (&type->s_umount_key#86){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880268020d8 (&type->s_umount_key#86){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline] #0: ffff8880268020d8 (&type->s_umount_key#86){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505 #1: ffff8880534b4918 (&(log)->loglock){+.+.}-{4:4}, at: jfs_umount+0x189/0x430 fs/jfs/jfs_umount.c:66 stack backtrace: CPU: 1 UID: 0 PID: 5628 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 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+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1b10 kernel/locking/mutex.c:820 jfs_commit_inode+0x1f5/0x4b0 fs/jfs/inode.c:108 jfs_write_inode+0xfb/0x230 fs/jfs/inode.c:138 write_inode fs/fs-writeback.c:1584 [inline] __writeback_single_inode+0xcd4/0x1350 fs/fs-writeback.c:1827 writeback_single_inode+0x4d3/0xf30 fs/fs-writeback.c:1883 write_inode_now+0x174/0x1f0 fs/fs-writeback.c:2974 iput_final fs/inode.c:1950 [inline] iput.part.0+0x7f3/0xf50 fs/inode.c:2009 iput+0x35/0x40 fs/inode.c:1975 diFreeSpecial+0x76/0x100 fs/jfs/jfs_imap.c:552 jfs_umount+0x1a2/0x430 fs/jfs/jfs_umount.c:72 jfs_put_super+0x88/0x1a0 fs/jfs/super.c:194 generic_shutdown_super+0x167/0x360 fs/super.c:646 kill_block_super+0x3b/0xa0 fs/super.c:1725 deactivate_locked_super+0xc1/0x1b0 fs/super.c:476 deactivate_super fs/super.c:509 [inline] deactivate_super+0xe7/0x110 fs/super.c:505 cleanup_mnt+0x21f/0x450 fs/namespace.c:1312 task_work_run+0x150/0x240 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+0x107/0x4f0 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+0x706/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f01bdf9e017 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:00007ffd3abf1c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f01be032120 RCX: 00007f01bdf9e017 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd3abf1d20 RBP: 00007ffd3abf1d20 R08: 00007ffd3abf2d20 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd3abf2db0 R13: 00007f01be032120 R14: 0000000000036c67 R15: 00007ffd3abf2df0