====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:5/130 is trying to acquire lock: ffff888059945ac8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline] ffff888059945ac8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1884 but task is already holding lock: ffff888031124bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline] ffff888031124bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x170/0x2f0 fs/ext4/inode.c:2806 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+0x44/0x1a0 include/linux/percpu-rwsem.h:51 ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline] ext4_writepages+0x170/0x2f0 fs/ext4/inode.c:2806 do_writepages+0x3a2/0x600 mm/page-writeback.c:2575 __writeback_single_inode+0x153/0xee0 fs/fs-writeback.c:1635 writeback_single_inode+0x211/0x720 fs/fs-writeback.c:1756 write_inode_now+0x161/0x1e0 fs/fs-writeback.c:2802 iput_final fs/inode.c:1807 [inline] iput+0x5b2/0x920 fs/inode.c:1846 ext4_xattr_block_set+0x273a/0x32a0 fs/ext4/xattr.c:2211 ext4_xattr_move_to_block fs/ext4/xattr.c:2679 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2754 [inline] ext4_expand_extra_isize_ea+0x10ea/0x19e0 fs/ext4/xattr.c:2846 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5967 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6010 [inline] __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6088 ext4_evict_inode+0x7ed/0xea0 fs/ext4/inode.c:252 evict+0x486/0x870 fs/inode.c:705 ext4_orphan_cleanup+0xbd4/0x1400 fs/ext4/orphan.c:470 __ext4_fill_super fs/ext4/super.c:5601 [inline] ext4_fill_super+0x5de4/0x66c0 fs/ext4/super.c:5724 get_tree_bdev+0x3e4/0x510 fs/super.c:1591 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&ei->xattr_sem){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1884 ext4_do_writepages+0x4c2/0x38d0 fs/ext4/inode.c:2604 ext4_writepages+0x1a8/0x2f0 fs/ext4/inode.c:2807 do_writepages+0x3a2/0x600 mm/page-writeback.c:2575 __writeback_single_inode+0x153/0xee0 fs/fs-writeback.c:1635 writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926 wb_writeback+0x450/0xba0 fs/fs-writeback.c:2105 wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0x3ff/0xe20 fs/fs-writeback.c:2292 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 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/u4:5/130: #0: ffff88801a27ed38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88801a27ed38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90002d87d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90002d87d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff888031124bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline] #2: ffff888031124bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x170/0x2f0 fs/ext4/inode.c:2806 stack backtrace: CPU: 0 PID: 130 Comm: kworker/u4:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: writeback wb_workfn (flush-7:7) Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1884 ext4_do_writepages+0x4c2/0x38d0 fs/ext4/inode.c:2604 ext4_writepages+0x1a8/0x2f0 fs/ext4/inode.c:2807 do_writepages+0x3a2/0x600 mm/page-writeback.c:2575 __writeback_single_inode+0x153/0xee0 fs/fs-writeback.c:1635 writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926 wb_writeback+0x450/0xba0 fs/fs-writeback.c:2105 wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0x3ff/0xe20 fs/fs-writeback.c:2292 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 EXT4-fs error (device loop7): ext4_mb_generate_buddy:1215: group 0, block bitmap and bg descriptor inconsistent: 25 vs 281 free clusters EXT4-fs (loop7): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 28 EXT4-fs (loop7): This should not happen!! Data will be lost EXT4-fs (loop7): Total free blocks count 0 EXT4-fs (loop7): Free/Dirty block details EXT4-fs (loop7): free_blocks=4096 EXT4-fs (loop7): dirty_blocks=512 EXT4-fs (loop7): Block reservation details EXT4-fs (loop7): i_reserved_data_blocks=32 EXT4-fs (loop7): Delayed block allocation failed for inode 15 at logical offset 18 with max blocks 480 with error 28