====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u8:9/3438 is trying to acquire lock: ffff888033f66950 (jbd2_handle){++++}-{0:0}, at: wait_transaction_locked+0x17c/0x230 fs/jbd2/transaction.c:151 but task is already holding lock: ffff888033f64b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x27a/0x600 mm/page-writeback.c:2598 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:1820 [inline] ext4_writepages+0x224/0x7d0 fs/ext4/inode.c:3025 do_writepages+0x27a/0x600 mm/page-writeback.c:2598 __writeback_single_inode+0x168/0x14a0 fs/fs-writeback.c:1737 writeback_single_inode+0x425/0x10f0 fs/fs-writeback.c:1858 write_inode_now+0x170/0x1e0 fs/fs-writeback.c:2924 iput_final fs/inode.c:1941 [inline] iput.part.0+0x815/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 ext4_xattr_block_set+0x67c/0x3640 fs/ext4/xattr.c:2203 ext4_xattr_move_to_block fs/ext4/xattr.c:2668 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2743 [inline] ext4_expand_extra_isize_ea+0x1442/0x1ab0 fs/ext4/xattr.c:2831 __ext4_expand_extra_isize+0x346/0x480 fs/ext4/inode.c:6349 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6392 [inline] __ext4_mark_inode_dirty+0x544/0x840 fs/ext4/inode.c:6470 ext4_evict_inode+0x713/0x1730 fs/ext4/inode.c:253 evict+0x3c2/0xad0 fs/inode.c:837 iput_final fs/inode.c:1951 [inline] iput.part.0+0x621/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 ext4_orphan_cleanup+0x731/0x11e0 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5658 [inline] ext4_fill_super+0x7ec1/0xb570 fs/ext4/super.c:5777 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1691 vfs_get_tree+0x8e/0x330 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount fs/namespace.c:3712 [inline] path_mount+0x7bf/0x23a0 fs/namespace.c:4022 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount fs/namespace.c:4201 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&ei->xattr_sem){++++}-{4:4}: down_read+0x9b/0x460 kernel/locking/rwsem.c:1537 ext4_setattr+0x869/0x28e0 fs/ext4/inode.c:5865 notify_change+0x6d2/0x1290 fs/attr.c:546 chown_common+0x549/0x680 fs/open.c:788 do_fchownat+0x1a7/0x200 fs/open.c:819 __do_sys_chown fs/open.c:839 [inline] __se_sys_chown fs/open.c:837 [inline] __x64_sys_chown+0x7b/0xc0 fs/open.c:837 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/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+0x1669/0x2890 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 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+0x3e7/0x1410 fs/jbd2/transaction.c:403 jbd2__journal_start+0x394/0x6a0 fs/jbd2/transaction.c:501 __ext4_journal_start_sb+0x195/0x640 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xc23/0x3c80 fs/ext4/inode.c:2914 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3026 do_writepages+0x27a/0x600 mm/page-writeback.c:2598 __writeback_single_inode+0x168/0x14a0 fs/fs-writeback.c:1737 writeback_sb_inodes+0x72e/0x1ce0 fs/fs-writeback.c:2030 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2107 wb_writeback+0x799/0xae0 fs/fs-writeback.c:2218 wb_check_old_data_flush fs/fs-writeback.c:2322 [inline] wb_do_writeback fs/fs-writeback.c:2375 [inline] wb_workfn+0x8a0/0xbb0 fs/fs-writeback.c:2403 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 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/u8:9/3438: #0: ffff8881412d4148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000be97c90 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff888033f620e0 (&type->s_umount_key#31){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:563 #3: ffff888033f64b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x27a/0x600 mm/page-writeback.c:2598 stack backtrace: CPU: 0 UID: 0 PID: 3438 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x340 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+0x1669/0x2890 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 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+0x3e7/0x1410 fs/jbd2/transaction.c:403 jbd2__journal_start+0x394/0x6a0 fs/jbd2/transaction.c:501 __ext4_journal_start_sb+0x195/0x640 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xc23/0x3c80 fs/ext4/inode.c:2914 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3026 do_writepages+0x27a/0x600 mm/page-writeback.c:2598 __writeback_single_inode+0x168/0x14a0 fs/fs-writeback.c:1737 writeback_sb_inodes+0x72e/0x1ce0 fs/fs-writeback.c:2030 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2107 wb_writeback+0x799/0xae0 fs/fs-writeback.c:2218 wb_check_old_data_flush fs/fs-writeback.c:2322 [inline] wb_do_writeback fs/fs-writeback.c:2375 [inline] wb_workfn+0x8a0/0xbb0 fs/fs-writeback.c:2403 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246