====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.8.1493/11623 is trying to acquire lock: ffff888077d1b2c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ffff888077d1b2c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1902 but task is already holding lock: ffff88804b970c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1768 [inline] ffff88804b970c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2809 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:1768 [inline] ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2809 do_writepages+0x351/0x590 mm/page-writeback.c:2575 __writeback_single_inode+0x14e/0xee0 fs/fs-writeback.c:1686 writeback_single_inode+0x21f/0x760 fs/fs-writeback.c:1807 write_inode_now+0x183/0x210 fs/fs-writeback.c:2859 iput_final fs/inode.c:1807 [inline] iput+0x58f/0x900 fs/inode.c:1846 ext4_xattr_block_set+0x2228/0x2fe0 fs/ext4/xattr.c:2148 ext4_xattr_move_to_block fs/ext4/xattr.c:2666 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2741 [inline] ext4_expand_extra_isize_ea+0x128f/0x1e70 fs/ext4/xattr.c:2829 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5991 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6034 [inline] __ext4_mark_inode_dirty+0x458/0x6d0 fs/ext4/inode.c:6112 ext4_evict_inode+0x7dd/0xe70 fs/ext4/inode.c:254 evict+0x4b7/0x8a0 fs/inode.c:705 ext4_orphan_cleanup+0xc33/0x1470 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5621 [inline] ext4_fill_super+0x5fb5/0x6870 fs/ext4/super.c:5744 get_tree_bdev+0x3e5/0x520 fs/super.c:1591 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24a/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 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+0x37ef/0x7d80 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 down_write+0x97/0x200 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1902 ext4_do_writepages+0x4f2/0x3990 fs/ext4/inode.c:2607 ext4_writepages+0x1dd/0x350 fs/ext4/inode.c:2810 do_writepages+0x351/0x590 mm/page-writeback.c:2575 filemap_fdatawrite_wbc+0x122/0x180 mm/filemap.c:390 __filemap_fdatawrite_range mm/filemap.c:423 [inline] __filemap_fdatawrite mm/filemap.c:429 [inline] filemap_flush+0xe4/0x150 mm/filemap.c:456 ext4_release_file+0x82/0x310 fs/ext4/file.c:169 __fput+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 get_signal+0x11da/0x1390 kernel/signal.c:2679 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 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 *** 1 lock held by syz.8.1493/11623: #0: ffff88804b970c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1768 [inline] #0: ffff88804b970c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2809 stack backtrace: CPU: 0 PID: 11623 Comm: syz.8.1493 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 check_noncircular+0x2fc/0x400 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+0x37ef/0x7d80 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 down_write+0x97/0x200 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1902 ext4_do_writepages+0x4f2/0x3990 fs/ext4/inode.c:2607 ext4_writepages+0x1dd/0x350 fs/ext4/inode.c:2810 do_writepages+0x351/0x590 mm/page-writeback.c:2575 filemap_fdatawrite_wbc+0x122/0x180 mm/filemap.c:390 __filemap_fdatawrite_range mm/filemap.c:423 [inline] __filemap_fdatawrite mm/filemap.c:429 [inline] filemap_flush+0xe4/0x150 mm/filemap.c:456 ext4_release_file+0x82/0x310 fs/ext4/file.c:169 __fput+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 get_signal+0x11da/0x1390 kernel/signal.c:2679 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8995f9de99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe939ef318 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffe939ef400 RCX: 00007f8995f9de99 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 000000000005b071 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b2f820000 R11: 0000000000000246 R12: 00007ffe939ef440 R13: 00007f8996225fac R14: 000000000005b333 R15: 00007f8996225fa0 EXT4-fs error (device loop8): ext4_mb_generate_buddy:1244: group 0, block bitmap and bg descriptor inconsistent: 0 vs 150994969 free clusters EXT4-fs (loop8): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 28 EXT4-fs (loop8): This should not happen!! Data will be lost EXT4-fs (loop8): Total free blocks count 0 EXT4-fs (loop8): Free/Dirty block details EXT4-fs (loop8): free_blocks=2415919504 EXT4-fs (loop8): dirty_blocks=16 EXT4-fs (loop8): Block reservation details EXT4-fs (loop8): i_reserved_data_blocks=1