====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u8:8/1030 is trying to acquire lock: ffff888035d76bb0 (jbd2_handle){++++}-{0:0}, at: wait_transaction_locked+0x1a9/0x280 fs/jbd2/transaction.c:151 but task is already holding lock: ffff888035e6ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff888035e6ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1876 [inline] ffff888035e6ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3042 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:1876 [inline] ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3042 do_writepages+0x338/0x560 mm/page-writeback.c:2571 __writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1787 writeback_single_inode+0x4dd/0xe10 fs/fs-writeback.c:1906 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:3060 iput_final fs/inode.c:2009 [inline] iput+0x98b/0xf00 fs/inode.c:2068 ext4_xattr_block_set+0x22e4/0x2a80 fs/ext4/xattr.c:2153 ext4_xattr_move_to_block fs/ext4/xattr.c:2671 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2746 [inline] ext4_expand_extra_isize_ea+0x1342/0x1e70 fs/ext4/xattr.c:2834 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6486 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6529 [inline] __ext4_mark_inode_dirty+0x455/0x700 fs/ext4/inode.c:6607 ext4_evict_inode+0x976/0x10c0 fs/ext4/inode.c:267 evict+0x624/0xb50 fs/inode.c:825 ext4_orphan_cleanup+0xc7a/0x14c0 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5705 [inline] ext4_fill_super+0x5cc0/0x65d0 fs/ext4/super.c:5828 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1634 vfs_get_tree+0x92/0x2a0 fs/super.c:1694 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3765 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3841 do_mount fs/namespace.c:4174 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4367 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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:1631 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_xattr_set_handle+0x194/0x1540 fs/ext4/xattr.c:2374 ext4_initxattrs+0xa4/0x120 fs/ext4/xattr_security.c:44 security_inode_init_security+0x29b/0x3e0 security/security.c:1370 __ext4_new_inode+0x3435/0x3e40 fs/ext4/ialloc.c:1332 ext4_create+0x237/0x480 fs/ext4/namei.c:2827 lookup_open fs/namei.c:4508 [inline] open_last_lookups fs/namei.c:4608 [inline] path_openat+0x1344/0x3850 fs/namei.c:4860 do_file_open+0x23e/0x4a0 fs/namei.c:4892 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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+0x1520/0x2ce0 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:-1 [inline] start_this_handle+0x7ea/0x2210 fs/jbd2/transaction.c:403 jbd2__journal_start+0x2c0/0x5c0 fs/jbd2/transaction.c:502 __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+0x101b/0x47a0 fs/ext4/inode.c:2931 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3043 do_writepages+0x338/0x560 mm/page-writeback.c:2571 __writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1787 writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2079 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2155 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2266 wb_check_old_data_flush fs/fs-writeback.c:2370 [inline] wb_do_writeback fs/fs-writeback.c:2449 [inline] wb_workfn+0xc98/0x10f0 fs/fs-writeback.c:2477 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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/u8:8/1030: #0: ffff88801eadc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801eadc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc900061ffc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc900061ffc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff888035d920d0 (&type->s_umount_key#33){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:566 #3: ffff888035e6ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #3: ffff888035e6ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1876 [inline] #3: ffff888035e6ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3042 stack backtrace: CPU: 1 UID: 0 PID: 1030 Comm: kworker/u8:8 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 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+0x1520/0x2ce0 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:-1 [inline] start_this_handle+0x7ea/0x2210 fs/jbd2/transaction.c:403 jbd2__journal_start+0x2c0/0x5c0 fs/jbd2/transaction.c:502 __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+0x101b/0x47a0 fs/ext4/inode.c:2931 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3043 do_writepages+0x338/0x560 mm/page-writeback.c:2571 __writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1787 writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2079 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2155 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2266 wb_check_old_data_flush fs/fs-writeback.c:2370 [inline] wb_do_writeback fs/fs-writeback.c:2449 [inline] wb_workfn+0xc98/0x10f0 fs/fs-writeback.c:2477 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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