====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u8:10/1152 is trying to acquire lock: ffff8880355fc950 (jbd2_handle){++++}-{0:0}, at: wait_transaction_locked+0x1a9/0x280 fs/jbd2/transaction.c:151 but task is already holding lock: ffff888035866b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff888035866b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1813 [inline] ffff888035866b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018 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+0x48/0x1c0 include/linux/percpu-rwsem.h:53 percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1813 [inline] ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 __writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750 writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1869 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2954 iput_final fs/inode.c:1956 [inline] iput+0x8c1/0xe80 fs/inode.c:2015 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:6297 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6340 [inline] __ext4_mark_inode_dirty+0x45c/0x730 fs/ext4/inode.c:6418 ext4_evict_inode+0x7a1/0xeb0 fs/ext4/inode.c:255 evict+0x61e/0xb10 fs/inode.c:846 ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5670 [inline] ext4_fill_super+0x59ff/0x6320 fs/ext4/super.c:5793 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:3762 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3838 do_mount fs/namespace.c:4161 [inline] __do_sys_mount fs/namespace.c:4350 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4327 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&ei->xattr_sem){++++}-{4:4}: down_read+0x47/0x2e0 kernel/locking/rwsem.c:1537 ext4_setattr+0x888/0x1c60 fs/ext4/inode.c:5813 notify_change+0xc1a/0xf40 fs/attr.c:556 chown_common+0x466/0x6b0 fs/open.c:778 do_fchownat+0x14c/0x250 fs/open.c:806 __do_sys_chown fs/open.c:826 [inline] __se_sys_chown fs/open.c:824 [inline] __x64_sys_chown+0x82/0xa0 fs/open.c:824 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/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+0xf0/0x2e0 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+0x203/0x620 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xf94/0x46e0 fs/ext4/inode.c:2907 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3019 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 __writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750 writeback_sb_inodes+0x944/0x19a0 fs/fs-writeback.c:2041 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2118 wb_writeback+0x46a/0xb70 fs/fs-writeback.c:2229 wb_check_old_data_flush fs/fs-writeback.c:2333 [inline] wb_do_writeback fs/fs-writeback.c:2386 [inline] wb_workfn+0xb4c/0xf50 fs/fs-writeback.c:2414 process_one_work+0x949/0x1650 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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/u8:10/1152: #0: ffff88801c6ca148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254 #1: ffffc90004f6fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255 #2: ffff8880358900e0 (&type->s_umount_key#34){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff888035866b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #3: ffff888035866b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1813 [inline] #3: ffff888035866b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018 stack backtrace: CPU: 1 UID: 0 PID: 1152 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 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+0xf0/0x2e0 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+0x203/0x620 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xf94/0x46e0 fs/ext4/inode.c:2907 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3019 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 __writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750 writeback_sb_inodes+0x944/0x19a0 fs/fs-writeback.c:2041 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2118 wb_writeback+0x46a/0xb70 fs/fs-writeback.c:2229 wb_check_old_data_flush fs/fs-writeback.c:2333 [inline] wb_do_writeback fs/fs-writeback.c:2386 [inline] wb_workfn+0xb4c/0xf50 fs/fs-writeback.c:2414 process_one_work+0x949/0x1650 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245