=========================[ 141.084958][ T5835] ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz-executor/5835 is trying to acquire lock: ffff88805dc4c580 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 but task is already holding lock: ffff88803b706950 (&(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/rtmutex_api.c:534 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:553 lmLog+0x78/0xa30 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+0xce/0x140 fs/jfs/inode.c:420 jfs_setattr+0x4f8/0x760 fs/jfs/file.c:123 notify_change+0xc18/0xf60 fs/attr.c:556 do_truncate+0x1c2/0x250 fs/open.c:68 handle_truncate fs/namei.c:4307 [inline] do_open fs/namei.c:4703 [inline] path_openat+0x2fc4/0x38a0 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_creat fs/open.c:1448 [inline] __se_sys_creat fs/open.c:1442 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1442 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/rtmutex_api.c:534 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:553 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+0x75d/0x10e0 fs/fs-writeback.c:1827 writeback_single_inode+0x488/0xd60 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+0xed/0x480 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/5835: #0: ffff888062b7a0d0 (&type->s_umount_key#95){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888062b7a0d0 (&type->s_umount_key#95){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888062b7a0d0 (&type->s_umount_key#95){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffff88803b706950 (&(log)->loglock){+.+.}-{4:4}, at: jfs_umount+0x17f/0x3d0 fs/jfs/jfs_umount.c:66 stack backtrace: CPU: 0 UID: 0 PID: 5835 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} 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/rtmutex_api.c:534 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:553 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+0x75d/0x10e0 fs/fs-writeback.c:1827 writeback_single_inode+0x488/0xd60 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+0xed/0x480 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: 0033:0x7fbd2ceee017 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:00007fff7238dd78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fbd2cf82120 RCX: 00007fbd2ceee017 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff7238de30 RBP: 00007fff7238de30 R08: 00007fff7238ee30 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff7238eec0 R13: 00007fbd2cf82120 R14: 000000000002217c R15: 00007fff7238ef00 ------------[ cut here ]------------ rtmutex deadlock detected WARNING: kernel/locking/rtmutex.c:1687 at rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1687, CPU#0: syz-executor/5835 Modules linked in: CPU: 0 UID: 0 PID: 5835 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1687 Code: 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 41 54 53 83 ff dd 0f 85 81 00 00 00 48 89 f7 e8 d6 3a 01 00 48 8d 3d 7f a6 5f 04 <67> 48 0f b9 3a 4c 8d 3d 00 00 00 00 65 48 8b 1d 43 ee 42 07 4c 8d RSP: 0018:ffffc900044a7390 EFLAGS: 00010286 RAX: 0000000080000000 RBX: ffffc900044a7420 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8ba73c40 RDI: ffffffff8f8f0830 RBP: ffffc900044a7528 R08: ffffffff8f8bd1f7 R09: 1ffffffff1f17a3e R10: dffffc0000000000 R11: fffffbfff1f17a3f R12: 1ffff92000894e80 R13: ffffffff8b2f5bfd R14: ffff88803b7068f8 R15: dffffc0000000000 FS: 0000555562481500(0000) GS:ffff8881260fb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f02ec31d000 CR3: 000000003abb0000 CR4: 00000000003526f0 Call Trace: __rt_mutex_slowlock kernel/locking/rtmutex.c:1749 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1776 [inline] rt_mutex_slowlock+0x73a/0x780 kernel/locking/rtmutex.c:1816 __rt_mutex_lock kernel/locking/rtmutex.c:1831 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:553 lmLog+0x78/0xa30 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:1584 [inline] __writeback_single_inode+0x75d/0x10e0 fs/fs-writeback.c:1827 writeback_single_inode+0x488/0xd60 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+0xed/0x480 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: 0033:0x7fbd2ceee017 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:00007fff7238dd78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fbd2cf82120 RCX: 00007fbd2ceee017 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff7238de30 RBP: 00007fff7238de30 R08: 00007fff7238ee30 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff7238eec0 R13: 00007fbd2cf82120 R14: 000000000002217c R15: 00007fff7238ef00 ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 41 57 push %r15 b: 41 56 push %r14 d: 41 55 push %r13 f: 41 54 push %r12 11: 53 push %rbx 12: 83 ff dd cmp $0xffffffdd,%edi 15: 0f 85 81 00 00 00 jne 0x9c 1b: 48 89 f7 mov %rsi,%rdi 1e: e8 d6 3a 01 00 call 0x13af9 23: 48 8d 3d 7f a6 5f 04 lea 0x45fa67f(%rip),%rdi # 0x45fa6a9 * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 4c 8d 3d 00 00 00 00 lea 0x0(%rip),%r15 # 0x36 36: 65 48 8b 1d 43 ee 42 mov %gs:0x742ee43(%rip),%rbx # 0x742ee81 3d: 07 3e: 4c rex.WR 3f: 8d .byte 0x8d