====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ kworker/u8:8/1916 is trying to acquire lock: ffff888058506108 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff888058506108 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1797 but task is already holding lock: ffff888058a8eb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff888058a8eb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1820 [inline] ffff888058a8eb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1ca/0x350 fs/ext4/inode.c:3025 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&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:1820 [inline] ext4_writepages+0x1ca/0x350 fs/ext4/inode.c:3025 do_writepages+0x32e/0x550 mm/page-writeback.c:2598 __writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737 writeback_single_inode+0x493/0xc70 fs/fs-writeback.c:1858 write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2924 iput_final fs/inode.c:1941 [inline] iput+0xa77/0x1030 fs/inode.c:2003 ext4_xattr_block_set+0x1fce/0x2ac0 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+0x12da/0x1ea0 fs/ext4/xattr.c:2831 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6349 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6392 [inline] __ext4_mark_inode_dirty+0x45c/0x6e0 fs/ext4/inode.c:6470 ext4_evict_inode+0x79c/0xe60 fs/ext4/inode.c:253 evict+0x5f4/0xae0 fs/inode.c:837 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5658 [inline] ext4_fill_super+0x58a1/0x6160 fs/ext4/super.c:5777 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3712 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&ei->xattr_sem){++++}-{4:4}: 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+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1797 ext4_do_writepages+0x4e6/0x4500 fs/ext4/inode.c:2811 ext4_writepages+0x203/0x350 fs/ext4/inode.c:3026 do_writepages+0x32e/0x550 mm/page-writeback.c:2598 __writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737 writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2030 wb_writeback+0x42b/0xaa0 fs/fs-writeback.c:2216 wb_do_writeback fs/fs-writeback.c:2363 [inline] wb_workfn+0x3f9/0xed0 fs/fs-writeback.c:2403 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 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: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); *** DEADLOCK *** 3 locks held by kworker/u8:8/1916: #0: ffff88801eacc948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc90005b17b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffff888058a8eb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #2: ffff888058a8eb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1820 [inline] #2: ffff888058a8eb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1ca/0x350 fs/ext4/inode.c:3025 stack backtrace: CPU: 0 UID: 0 PID: 1916 Comm: kworker/u8:8 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 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+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1797 ext4_do_writepages+0x4e6/0x4500 fs/ext4/inode.c:2811 ext4_writepages+0x203/0x350 fs/ext4/inode.c:3026 do_writepages+0x32e/0x550 mm/page-writeback.c:2598 __writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737 writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2030 wb_writeback+0x42b/0xaa0 fs/fs-writeback.c:2216 wb_do_writeback fs/fs-writeback.c:2363 [inline] wb_workfn+0x3f9/0xed0 fs/fs-writeback.c:2403 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 EXT4-fs error (device loop2): ext4_mb_generate_buddy:1306: group 0, block bitmap and bg descriptor inconsistent: 25 vs 4128793 free clusters EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 28 EXT4-fs (loop2): This should not happen!! Data will be lost EXT4-fs (loop2): Total free blocks count 0 EXT4-fs (loop2): Free/Dirty block details EXT4-fs (loop2): free_blocks=66060288 EXT4-fs (loop2): dirty_blocks=16 EXT4-fs (loop2): Block reservation details EXT4-fs (loop2): i_reserved_data_blocks=1 netdevice_event(NETDEV_UNREGISTER) for ffff88802fc7e000 on ffff88802b4cc000 start netdevice_event(NETDEV_UNREGISTER) for ffff88802fc7e000 on ffff88802b4cc000 end