loop5: detected capacity change from 0 to 512
EXT4-fs (loop5): 1 truncate cleaned up
EXT4-fs (loop5): mounted filesystem without journal. Quota mode: none.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.5.583/7127 is trying to acquire lock:
ffff888071b514d8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline]
ffff888071b514d8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1930

but task is already holding lock:
ffff888149a8ec18 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2e70 fs/ext4/inode.c:2717

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+0x213/0x2e70 fs/ext4/inode.c:2717
       do_writepages+0x3c6/0x640 mm/page-writeback.c:2491
       __writeback_single_inode+0x153/0x1170 fs/fs-writeback.c:1673
       writeback_single_inode+0x3d2/0x8e0 fs/fs-writeback.c:1794
       write_inode_now+0x17f/0x210 fs/fs-writeback.c:2837
       iput_final fs/inode.c:1821 [inline]
       iput+0x643/0x9c0 fs/inode.c:1860
       ext4_xattr_block_set+0x2239/0x2ff0 fs/ext4/xattr.c:2097
       ext4_xattr_move_to_block fs/ext4/xattr.c:2615 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2690 [inline]
       ext4_expand_extra_isize_ea+0x13d3/0x1d50 fs/ext4/xattr.c:2778
       __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:6003
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:6046 [inline]
       __ext4_mark_inode_dirty+0x478/0x760 fs/ext4/inode.c:6124
       ext4_evict_inode+0xa67/0x10e0 fs/ext4/inode.c:281
       evict+0x4b6/0x8b0 fs/inode.c:705
       ext4_orphan_cleanup+0xc32/0x1470 fs/ext4/orphan.c:472
       __ext4_fill_super fs/ext4/super.c:5574 [inline]
       ext4_fill_super+0x6f0c/0x78f0 fs/ext4/super.c:5693
       get_tree_bdev+0x3e6/0x610 fs/super.c:1377
       vfs_get_tree+0x88/0x270 fs/super.c:1584
       do_new_mount+0x247/0xa40 fs/namespace.c:3078
       do_mount fs/namespace.c:3421 [inline]
       __do_sys_mount fs/namespace.c:3629 [inline]
       __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 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:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3830 [inline]
       __lock_acquire+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
       lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline]
       ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1930
       ext4_writepages+0x599/0x2e70 fs/ext4/inode.c:2763
       do_writepages+0x3c6/0x640 mm/page-writeback.c:2491
       filemap_fdatawrite_wbc+0x11e/0x180 mm/filemap.c:388
       __filemap_fdatawrite_range mm/filemap.c:421 [inline]
       file_write_and_wait_range+0x159/0x230 mm/filemap.c:774
       ext4_sync_file+0x22a/0xc30 fs/ext4/fsync.c:151
       generic_write_sync include/linux/fs.h:2973 [inline]
       ext4_buffered_write_iter+0x2de/0x380 fs/ext4/file.c:292
       ext4_file_write_iter+0x1e3/0x17d0 fs/ext4/file.c:-1
       call_write_iter include/linux/fs.h:2271 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x482/0x9a0 fs/read_write.c:584
       ksys_pwrite64 fs/read_write.c:699 [inline]
       __do_sys_pwrite64 fs/read_write.c:709 [inline]
       __se_sys_pwrite64 fs/read_write.c:706 [inline]
       __x64_sys_pwrite64+0x194/0x220 fs/read_write.c:706
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->s_writepages_rwsem);
                               lock(&ei->xattr_sem);
                               lock(&sbi->s_writepages_rwsem);
  lock(&ei->xattr_sem);

 *** DEADLOCK ***

2 locks held by syz.5.583/7127:
 #0: ffff888144b32460 (sb_writers#4){++++}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #1: ffff888149a8ec18 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2e70 fs/ext4/inode.c:2717

stack backtrace:
CPU: 1 PID: 7127 Comm: syz.5.583 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3830 [inline]
 __lock_acquire+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
 down_write+0x36/0x60 kernel/locking/rwsem.c:1573
 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline]
 ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1930
 ext4_writepages+0x599/0x2e70 fs/ext4/inode.c:2763
 do_writepages+0x3c6/0x640 mm/page-writeback.c:2491
 filemap_fdatawrite_wbc+0x11e/0x180 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 file_write_and_wait_range+0x159/0x230 mm/filemap.c:774
 ext4_sync_file+0x22a/0xc30 fs/ext4/fsync.c:151
 generic_write_sync include/linux/fs.h:2973 [inline]
 ext4_buffered_write_iter+0x2de/0x380 fs/ext4/file.c:292
 ext4_file_write_iter+0x1e3/0x17d0 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2271 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_pwrite64 fs/read_write.c:699 [inline]
 __do_sys_pwrite64 fs/read_write.c:709 [inline]
 __se_sys_pwrite64 fs/read_write.c:706 [inline]
 __x64_sys_pwrite64+0x194/0x220 fs/read_write.c:706
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f917259e159
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:00007f917353d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f9172825fa0 RCX: 00007f917259e159
RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000004
RBP: 00007f9172635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008000c61 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9172826038 R14: 00007f9172825fa0 R15: 00007fffd81049d8
 </TASK>
EXT4-fs error (device loop5): ext4_validate_block_bitmap:438: comm syz.5.583: bg 0: block 465: padding at end of block bitmap is not set
EXT4-fs (loop5): Remounting filesystem read-only