====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.6.793/10012 is trying to acquire lock: ffff8880766af448 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff8880766af448 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1797 but task is already holding lock: ffff88802a874b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff88802a874b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1820 [inline] ffff88802a874b98 (&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 filemap_writeback mm/filemap.c:387 [inline] filemap_fdatawrite_range mm/filemap.c:412 [inline] filemap_write_and_wait_range+0x21f/0x320 mm/filemap.c:684 filemap_write_and_wait include/linux/pagemap.h:65 [inline] ext4_ioctl_setflags fs/ext4/ioctl.c:647 [inline] ext4_fileattr_set+0x68e/0x1630 fs/ext4/ioctl.c:1024 vfs_fileattr_set+0x9c7/0xc50 fs/file_attr.c:299 ioctl_setflags+0x180/0x1e0 fs/file_attr.c:335 do_vfs_ioctl+0x8ed/0x1430 fs/ioctl.c:560 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 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 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 syz.6.793/10012: #0: ffff88807b41c420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:543 #1: ffff8880766af760 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff8880766af760 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: vfs_fileattr_set+0x153/0xc50 fs/file_attr.c:279 #2: ffff88802a874b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #2: ffff88802a874b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1820 [inline] #2: ffff88802a874b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1ca/0x350 fs/ext4/inode.c:3025 stack backtrace: CPU: 0 UID: 0 PID: 10012 Comm: syz.6.793 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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 filemap_writeback mm/filemap.c:387 [inline] filemap_fdatawrite_range mm/filemap.c:412 [inline] filemap_write_and_wait_range+0x21f/0x320 mm/filemap.c:684 filemap_write_and_wait include/linux/pagemap.h:65 [inline] ext4_ioctl_setflags fs/ext4/ioctl.c:647 [inline] ext4_fileattr_set+0x68e/0x1630 fs/ext4/ioctl.c:1024 vfs_fileattr_set+0x9c7/0xc50 fs/file_attr.c:299 ioctl_setflags+0x180/0x1e0 fs/file_attr.c:335 do_vfs_ioctl+0x8ed/0x1430 fs/ioctl.c:560 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 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 RIP: 0033:0x7f063338f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0634150038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f06335e5fa0 RCX: 00007f063338f749 RDX: 00002000000001c0 RSI: 0000000040086602 RDI: 0000000000000006 RBP: 00007f0633413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f06335e6038 R14: 00007f06335e5fa0 R15: 00007ffc5d234c88 EXT4-fs error (device loop6): ext4_mb_generate_buddy:1306: group 0, block bitmap and bg descriptor inconsistent: 25 vs 150994969 free clusters EXT4-fs (loop6): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 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=2415919104 EXT4-fs (loop6): dirty_blocks=64 EXT4-fs (loop6): Block reservation details EXT4-fs (loop6): i_reserved_data_blocks=4