EXT4-fs error (device loop3): ext4_mb_generate_buddy:1315: group 0, block bitmap and bg descriptor inconsistent: 25 vs 1305 free clusters ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.3.19792/865 is trying to acquire lock: ffff888077259da8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff888077259da8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1797 but task is already holding lock: ffff888086e2ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff888086e2ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1817 [inline] ffff888086e2ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018 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:1817 [inline] ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 __writeback_single_inode+0x133/0x1060 fs/fs-writeback.c:1750 writeback_single_inode+0x493/0xc70 fs/fs-writeback.c:1869 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2954 iput_final fs/inode.c:1947 [inline] iput+0x8c1/0xe80 fs/inode.c:2006 ext4_xattr_block_set+0x1fd4/0x2ad0 fs/ext4/xattr.c:2204 ext4_xattr_move_to_block fs/ext4/xattr.c:2669 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2744 [inline] ext4_expand_extra_isize_ea+0x12cf/0x1ea0 fs/ext4/xattr.c:2832 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6328 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6371 [inline] __ext4_mark_inode_dirty+0x45c/0x6e0 fs/ext4/inode.c:6449 ext4_evict_inode+0x7a1/0xe60 fs/ext4/inode.c:255 evict+0x61e/0xb10 fs/inode.c:837 ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5674 [inline] ext4_fill_super+0x59ff/0x6320 fs/ext4/super.c:5797 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 down_write+0x96/0x200 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+0x51e/0x4600 fs/ext4/inode.c:2804 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3019 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 filemap_writeback mm/filemap.c:387 [inline] filemap_fdatawrite_range mm/filemap.c:412 [inline] file_write_and_wait_range+0x36e/0x440 mm/filemap.c:786 generic_buffers_fsync_noflush+0x70/0x1d0 fs/buffer.c:610 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline] ext4_sync_file+0x321/0xad0 fs/ext4/fsync.c:147 generic_write_sync include/linux/fs.h:2640 [inline] ext4_buffered_write_iter+0x2ca/0x3a0 fs/ext4/file.c:306 ext4_file_write_iter+0x298/0x1bf0 fs/ext4/file.c:-1 do_iter_readv_writev+0x619/0x8c0 fs/read_write.c:-1 vfs_writev+0x33c/0x990 fs/read_write.c:1059 do_pwritev fs/read_write.c:1155 [inline] __do_sys_pwritev2 fs/read_write.c:1213 [inline] __se_sys_pwritev2+0x184/0x2a0 fs/read_write.c:1204 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 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 *** 2 locks held by syz.3.19792/865: #0: ffff88804df80420 (sb_writers#4){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff88804df80420 (sb_writers#4){.+.+}-{0:0}, at: vfs_writev+0x2aa/0x990 fs/read_write.c:1057 #1: ffff888086e2ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #1: ffff888086e2ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1817 [inline] #1: ffff888086e2ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018 stack backtrace: CPU: 1 UID: 0 PID: 865 Comm: syz.3.19792 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 down_write+0x96/0x200 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+0x51e/0x4600 fs/ext4/inode.c:2804 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3019 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 filemap_writeback mm/filemap.c:387 [inline] filemap_fdatawrite_range mm/filemap.c:412 [inline] file_write_and_wait_range+0x36e/0x440 mm/filemap.c:786 generic_buffers_fsync_noflush+0x70/0x1d0 fs/buffer.c:610 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline] ext4_sync_file+0x321/0xad0 fs/ext4/fsync.c:147 generic_write_sync include/linux/fs.h:2640 [inline] ext4_buffered_write_iter+0x2ca/0x3a0 fs/ext4/file.c:306 ext4_file_write_iter+0x298/0x1bf0 fs/ext4/file.c:-1 do_iter_readv_writev+0x619/0x8c0 fs/read_write.c:-1 vfs_writev+0x33c/0x990 fs/read_write.c:1059 do_pwritev fs/read_write.c:1155 [inline] __do_sys_pwritev2 fs/read_write.c:1213 [inline] __se_sys_pwritev2+0x184/0x2a0 fs/read_write.c:1204 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd197f9acb9 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:00007fd198df5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007fd198215fa0 RCX: 00007fd197f9acb9 RDX: 0000000000000001 RSI: 0000200000000100 RDI: 0000000000000004 RBP: 00007fd198008bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000005405 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd198216038 R14: 00007fd198215fa0 R15: 00007fff139055a8 EXT4-fs (loop3): Delayed block allocation failed for inode 15 at logical offset 21 with max blocks 43 with error 28 EXT4-fs (loop3): This should not happen!! Data will be lost EXT4-fs (loop3): Total free blocks count 0 EXT4-fs (loop3): Free/Dirty block details EXT4-fs (loop3): free_blocks=20480 EXT4-fs (loop3): dirty_blocks=64 EXT4-fs (loop3): Block reservation details EXT4-fs (loop3): i_reserved_data_blocks=4