====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u8:0/12 is trying to acquire lock: ffff888032286938 (jbd2_handle){++++}-{0:0}, at: wait_transaction_locked+0x17c/0x230 fs/jbd2/transaction.c:151 but task is already holding lock: ffff888031348c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2575 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 include/linux/percpu-rwsem.h:53 [inline] percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1815 [inline] ext4_writepages+0x21d/0x790 fs/ext4/inode.c:3030 do_writepages+0x278/0x600 mm/page-writeback.c:2575 __writeback_single_inode+0x164/0x1350 fs/fs-writeback.c:1762 writeback_single_inode+0x4d3/0xf30 fs/fs-writeback.c:1881 write_inode_now+0x174/0x1f0 fs/fs-writeback.c:2972 iput_final fs/inode.c:1950 [inline] iput.part.0+0x7f3/0xf50 fs/inode.c:2009 iput+0x35/0x40 fs/inode.c:1975 ext4_xattr_block_set+0x6f7/0x3660 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+0x17c6/0x1d70 fs/ext4/xattr.c:2832 __ext4_expand_extra_isize+0x346/0x480 fs/ext4/inode.c:6344 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6387 [inline] __ext4_mark_inode_dirty+0x67d/0x890 fs/ext4/inode.c:6465 ext4_evict_inode+0x846/0x1a30 fs/ext4/inode.c:267 evict+0x3c2/0xad0 fs/inode.c:841 iput_final fs/inode.c:1960 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2009 iput+0x35/0x40 fs/inode.c:1975 ext4_orphan_cleanup+0x71e/0x11e0 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5695 [inline] ext4_fill_super+0x916c/0xb5d0 fs/ext4/super.c:5818 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1694 vfs_get_tree+0x92/0x320 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount fs/namespace.c:3839 [inline] path_mount+0x7d0/0x23d0 fs/namespace.c:4159 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount fs/namespace.c:4338 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4338 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 (&ei->xattr_sem){++++}-{4:4}: down_read+0x99/0x450 kernel/locking/rwsem.c:1568 ext4_setattr+0x80f/0x27c0 fs/ext4/inode.c:5848 notify_change+0xb25/0x1330 fs/attr.c:556 chown_common+0x51e/0x6e0 fs/open.c:776 do_fchownat+0x18e/0x1f0 fs/open.c:804 __do_sys_chown fs/open.c:824 [inline] __se_sys_chown fs/open.c:822 [inline] __x64_sys_chown+0x7b/0xc0 fs/open.c:822 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 (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+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 wait_transaction_locked+0x191/0x230 fs/jbd2/transaction.c:151 add_transaction_credits+0x110/0xe60 fs/jbd2/transaction.c:222 start_this_handle+0x3de/0x13a0 fs/jbd2/transaction.c:403 jbd2__journal_start+0x394/0x6a0 fs/jbd2/transaction.c:501 __ext4_journal_start_sb+0x36d/0x670 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xc21/0x3f20 fs/ext4/inode.c:2919 ext4_writepages+0x347/0x790 fs/ext4/inode.c:3031 do_writepages+0x278/0x600 mm/page-writeback.c:2575 __writeback_single_inode+0x164/0x1350 fs/fs-writeback.c:1762 writeback_sb_inodes+0x766/0x1c60 fs/fs-writeback.c:2054 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2130 wb_writeback+0x720/0xb90 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+0x8dd/0xc00 fs/fs-writeback.c:2426 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3288 process_scheduled_works kernel/workqueue.c:3371 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3452 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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/u8:0/12: #0: ffff888020aaa940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3263 #1: ffffc90000117d08 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3264 #2: ffff88803134a0d8 (&type->s_umount_key#32){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:565 #3: ffff888031348c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2575 stack backtrace: CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(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 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 wait_transaction_locked+0x191/0x230 fs/jbd2/transaction.c:151 add_transaction_credits+0x110/0xe60 fs/jbd2/transaction.c:222 start_this_handle+0x3de/0x13a0 fs/jbd2/transaction.c:403 jbd2__journal_start+0x394/0x6a0 fs/jbd2/transaction.c:501 __ext4_journal_start_sb+0x36d/0x670 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xc21/0x3f20 fs/ext4/inode.c:2919 ext4_writepages+0x347/0x790 fs/ext4/inode.c:3031 do_writepages+0x278/0x600 mm/page-writeback.c:2575 __writeback_single_inode+0x164/0x1350 fs/fs-writeback.c:1762 writeback_sb_inodes+0x766/0x1c60 fs/fs-writeback.c:2054 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2130 wb_writeback+0x720/0xb90 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+0x8dd/0xc00 fs/fs-writeback.c:2426 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3288 process_scheduled_works kernel/workqueue.c:3371 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3452 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245