====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u8:11/2890 is trying to acquire lock: ffff0000f5814428 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff0000f5814428 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x30/0x11c fs/ext4/inline.c:1797 but task is already holding lock: ffff0000d59d4b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff0000d59d4b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1820 [inline] ffff0000d59d4b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x150/0x2a0 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+0x5c/0x298 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+0x150/0x2a0 fs/ext4/inode.c:3025 do_writepages+0x270/0x468 mm/page-writeback.c:2598 __writeback_single_inode+0x144/0x16b8 fs/fs-writeback.c:1737 writeback_single_inode+0x3e4/0xc2c fs/fs-writeback.c:1858 write_inode_now+0x13c/0x1a4 fs/fs-writeback.c:2924 iput_final fs/inode.c:1941 [inline] iput+0x9b8/0xfdc fs/inode.c:2003 ext4_xattr_block_set+0x13dc/0x24bc 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+0xeb8/0x1830 fs/ext4/xattr.c:2831 __ext4_expand_extra_isize+0x2a0/0x37c fs/ext4/inode.c:6349 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6392 [inline] __ext4_mark_inode_dirty+0x3a8/0x6fc fs/ext4/inode.c:6470 ext4_evict_inode+0x8dc/0x1058 fs/ext4/inode.c:253 evict+0x4e0/0xa74 fs/inode.c:837 iput_final fs/inode.c:1951 [inline] iput+0xc54/0xfdc fs/inode.c:2003 ext4_process_orphan+0x240/0x2b4 fs/ext4/orphan.c:358 ext4_orphan_cleanup+0x930/0x107c fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5658 [inline] ext4_fill_super+0x47e8/0x4f5c fs/ext4/super.c:5777 get_tree_bdev_flags+0x360/0x414 fs/super.c:1691 get_tree_bdev+0x2c/0x3c fs/super.c:1714 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5809 vfs_get_tree+0x90/0x28c fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount+0x284/0x944 fs/namespace.c:3712 path_mount+0x5b4/0xdfc 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] __arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4201 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 -> #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+0x1774/0x30a4 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x2e0 kernel/locking/lockdep.c:5868 down_write+0x50/0xc0 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x30/0x11c fs/ext4/inline.c:1797 ext4_do_writepages+0x3b0/0x3a18 fs/ext4/inode.c:2811 ext4_writepages+0x178/0x2a0 fs/ext4/inode.c:3026 do_writepages+0x270/0x468 mm/page-writeback.c:2598 __writeback_single_inode+0x144/0x16b8 fs/fs-writeback.c:1737 writeback_sb_inodes+0x73c/0x16b4 fs/fs-writeback.c:2030 wb_writeback+0x3b4/0xd70 fs/fs-writeback.c:2216 wb_do_writeback fs/fs-writeback.c:2363 [inline] wb_workfn+0x320/0xdc0 fs/fs-writeback.c:2403 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 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/u8:11/2890: #0: ffff0000c1ff3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x63c/0x1558 kernel/workqueue.c:3231 #1: ffff8000a2a97be0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6d0/0x1558 kernel/workqueue.c:3231 #2: ffff0000d59d4b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #2: ffff0000d59d4b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1820 [inline] #2: ffff0000d59d4b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x150/0x2a0 fs/ext4/inode.c:3025 stack backtrace: CPU: 0 UID: 0 PID: 2890 Comm: kworker/u8:11 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Workqueue: writeback wb_workfn (flush-7:6) Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 print_circular_bug+0x324/0x32c kernel/locking/lockdep.c:2043 check_noncircular+0x154/0x174 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+0x1774/0x30a4 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x2e0 kernel/locking/lockdep.c:5868 down_write+0x50/0xc0 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x30/0x11c fs/ext4/inline.c:1797 ext4_do_writepages+0x3b0/0x3a18 fs/ext4/inode.c:2811 ext4_writepages+0x178/0x2a0 fs/ext4/inode.c:3026 do_writepages+0x270/0x468 mm/page-writeback.c:2598 __writeback_single_inode+0x144/0x16b8 fs/fs-writeback.c:1737 writeback_sb_inodes+0x73c/0x16b4 fs/fs-writeback.c:2030 wb_writeback+0x3b4/0xd70 fs/fs-writeback.c:2216 wb_do_writeback fs/fs-writeback.c:2363 [inline] wb_workfn+0x320/0xdc0 fs/fs-writeback.c:2403 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 EXT4-fs error (device loop6): ext4_validate_block_bitmap:432: comm kworker/u8:11: bg 0: block 5: invalid block bitmap EXT4-fs (loop6): Delayed block allocation failed for inode 18 at logical offset 0 with max blocks 5 with error 28 EXT4-fs (loop6): This should not happen!! Data will be lost EXT4-fs (loop6): Total free blocks count 0 EXT4-fs (loop6): Free/Dirty block details EXT4-fs (loop6): free_blocks=0 EXT4-fs (loop6): dirty_blocks=5 EXT4-fs (loop6): Block reservation details EXT4-fs (loop6): i_reserved_data_blocks=5