====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u8:14/3539 is trying to acquire lock: ffff888037f90bb0 (jbd2_handle){++++}-{0:0}, at: wait_transaction_locked+0x1a9/0x280 fs/jbd2/transaction.c:151 but task is already holding lock: ffff888037f80cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff888037f80cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1815 [inline] ffff888037f80cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3030 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&sbi->s_writepages_rwsem){++++}-{0:0}: percpu_down_read_internal+0x48/0x1d0 include/linux/percpu-rwsem.h:53 percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1815 [inline] ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3030 do_writepages+0x32e/0x550 mm/page-writeback.c:2575 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1762 writeback_single_inode+0x488/0xd60 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 ext4_xattr_block_set+0x1fd4/0x2ad0 fs/ext4/xattr.c:2204 ext4_xattr_move_to_block fs/ext4/xattr.c:2669 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2744 [inline] ext4_expand_extra_isize_ea+0x12cf/0x1ea0 fs/ext4/xattr.c:2832 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6344 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6387 [inline] __ext4_mark_inode_dirty+0x45c/0x710 fs/ext4/inode.c:6465 ext4_evict_inode+0x986/0x10e0 fs/ext4/inode.c:267 evict+0x61e/0xb10 fs/inode.c:841 ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5695 [inline] ext4_fill_super+0x59bb/0x62d0 fs/ext4/super.c:5818 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 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 -> #1 (&ei->xattr_sem){++++}-{4:4}: down_write+0x3a/0x50 kernel/locking/rwsem.c:1625 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_xattr_set_handle+0x19c/0x14c0 fs/ext4/xattr.c:2372 ext4_initxattrs+0x9f/0x110 fs/ext4/xattr_security.c:44 security_inode_init_security+0x296/0x3d0 security/security.c:1370 __ext4_new_inode+0x3319/0x3ce0 fs/ext4/ialloc.c:1330 ext4_create+0x233/0x470 fs/ext4/namei.c:2820 lookup_open fs/namei.c:4511 [inline] open_last_lookups fs/namei.c:4611 [inline] path_openat+0x13b4/0x38a0 fs/namei.c:4855 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_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 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 (jbd2_handle){++++}-{0:0}: 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 wait_transaction_locked+0x1c2/0x280 fs/jbd2/transaction.c:151 add_transaction_credits fs/jbd2/transaction.c:222 [inline] start_this_handle+0x7dc/0x2290 fs/jbd2/transaction.c:403 jbd2__journal_start+0x2c0/0x5b0 fs/jbd2/transaction.c:501 __ext4_journal_start_sb+0x203/0x5d0 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xf79/0x4670 fs/ext4/inode.c:2919 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3031 do_writepages+0x32e/0x550 mm/page-writeback.c:2575 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1762 writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2054 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2130 wb_writeback+0x459/0xb00 fs/fs-writeback.c:2241 wb_check_old_data_flush fs/fs-writeback.c:2345 [inline] wb_do_writeback fs/fs-writeback.c:2398 [inline] wb_workfn+0xb17/0xf20 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 other info that might help us debug this: Chain exists of: jbd2_handle --> &ei->xattr_sem --> &sbi->s_writepages_rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); lock(jbd2_handle); *** DEADLOCK *** 4 locks held by kworker/u8:14/3539: #0: ffff88801f2ac138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801f2ac138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90010207c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90010207c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff888037f940d0 (&type->s_umount_key#32){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff888037f80cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #3: ffff888037f80cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1815 [inline] #3: ffff888037f80cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3030 stack backtrace: CPU: 1 UID: 0 PID: 3539 Comm: kworker/u8:14 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: writeback wb_workfn (flush-8:0) 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 wait_transaction_locked+0x1c2/0x280 fs/jbd2/transaction.c:151 add_transaction_credits fs/jbd2/transaction.c:222 [inline] start_this_handle+0x7dc/0x2290 fs/jbd2/transaction.c:403 jbd2__journal_start+0x2c0/0x5b0 fs/jbd2/transaction.c:501 __ext4_journal_start_sb+0x203/0x5d0 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xf79/0x4670 fs/ext4/inode.c:2919 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3031 do_writepages+0x32e/0x550 mm/page-writeback.c:2575 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1762 writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2054 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2130 wb_writeback+0x459/0xb00 fs/fs-writeback.c:2241 wb_check_old_data_flush fs/fs-writeback.c:2345 [inline] wb_do_writeback fs/fs-writeback.c:2398 [inline] wb_workfn+0xb17/0xf20 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