loop0: detected capacity change from 0 to 512
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.898/11856 is trying to acquire lock:
ffff88802fdacbd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline]
ffff88802fdacbd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x170/0x2f0 fs/ext4/inode.c:2806

but task is already holding lock:
ffff888077fc0ac8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
ffff888077fc0ac8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5993 [inline]
ffff888077fc0ac8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3dc/0x6e0 fs/ext4/inode.c:6074

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ei->xattr_sem){++++}-{3:3}:
       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
       filemap_fdatawrite_wbc+0x122/0x180 mm/filemap.c:390
       __filemap_fdatawrite_range mm/filemap.c:423 [inline]
       file_write_and_wait_range+0x171/0x240 mm/filemap.c:781
       generic_buffers_fsync_noflush+0x6f/0x160 fs/buffer.c:609
       ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
       ext4_sync_file+0x454/0xc10 fs/ext4/fsync.c:151
       generic_write_sync include/linux/fs.h:2651 [inline]
       ext4_buffered_write_iter+0x2c0/0x350 fs/ext4/file.c:305
       ext4_file_write_iter+0x1d9/0x1870 fs/ext4/file.c:-1
       do_iter_readv_writev fs/read_write.c:-1 [inline]
       do_iter_write+0x79a/0xc70 fs/read_write.c:860
       iter_file_splice_write+0x66f/0xc50 fs/splice.c:736
       do_splice_from fs/splice.c:933 [inline]
       direct_splice_actor+0xe8/0x130 fs/splice.c:1142
       splice_direct_to_actor+0x2f0/0x870 fs/splice.c:1088
       do_splice_direct+0x1b7/0x2c0 fs/splice.c:1194
       do_sendfile+0x5dc/0xf70 fs/read_write.c:1254
       __do_sys_sendfile64 fs/read_write.c:1322 [inline]
       __se_sys_sendfile64+0x13f/0x190 fs/read_write.c:1308
       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 (&sbi->s_writepages_rwsem){++++}-{0:0}:
       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
       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:1625
       writeback_single_inode+0x211/0x720 fs/fs-writeback.c:1746
       write_inode_now+0x161/0x1e0 fs/fs-writeback.c:2792
       iput_final fs/inode.c:1807 [inline]
       iput+0x5b2/0x920 fs/inode.c:1846
       ext4_xattr_block_set+0x273a/0x32a0 fs/ext4/xattr.c:2206
       ext4_xattr_move_to_block fs/ext4/xattr.c:2674 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2749 [inline]
       ext4_expand_extra_isize_ea+0x10ea/0x19e0 fs/ext4/xattr.c:2841
       __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5953
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:5996 [inline]
       __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6074
       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:474
       __ext4_fill_super fs/ext4/super.c:5608 [inline]
       ext4_fill_super+0x5de7/0x66c0 fs/ext4/super.c:5731
       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:3377
       do_mount fs/namespace.c:3717 [inline]
       __do_sys_mount fs/namespace.c:3926 [inline]
       __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3903
       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

other info that might help us debug this:

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

3 locks held by syz.0.898/11856:
 #0: ffff888078b020e0 (&type->s_umount_key#32){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888078b020e0 (&type->s_umount_key#32){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888078b020e0 (&type->s_umount_key#32){++++}-{3:3}, at: get_tree_bdev+0x344/0x510 fs/super.c:1589
 #1: ffff888078b02608 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff888078b02608 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1755 [inline]
 #1: ffff888078b02608 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x2b9/0xea0 fs/ext4/inode.c:213
 #2: ffff888077fc0ac8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
 #2: ffff888077fc0ac8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5993 [inline]
 #2: ffff888077fc0ac8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3dc/0x6e0 fs/ext4/inode.c:6074

stack backtrace:
CPU: 1 PID: 11856 Comm: syz.0.898 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 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
 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:1625
 writeback_single_inode+0x211/0x720 fs/fs-writeback.c:1746
 write_inode_now+0x161/0x1e0 fs/fs-writeback.c:2792
 iput_final fs/inode.c:1807 [inline]
 iput+0x5b2/0x920 fs/inode.c:1846
 ext4_xattr_block_set+0x273a/0x32a0 fs/ext4/xattr.c:2206
 ext4_xattr_move_to_block fs/ext4/xattr.c:2674 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2749 [inline]
 ext4_expand_extra_isize_ea+0x10ea/0x19e0 fs/ext4/xattr.c:2841
 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5953
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5996 [inline]
 __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6074
 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:474
 __ext4_fill_super fs/ext4/super.c:5608 [inline]
 ext4_fill_super+0x5de7/0x66c0 fs/ext4/super.c:5731
 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:3377
 do_mount fs/namespace.c:3717 [inline]
 __do_sys_mount fs/namespace.c:3926 [inline]
 __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3903
 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
RIP: 0033:0x7f8f93d9034a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f8f94bdee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8f94bdeef0 RCX: 00007f8f93d9034a
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007f8f94bdeeb0
RBP: 0000200000000180 R08: 00007f8f94bdeef0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007f8f94bdeeb0 R14: 0000000000000473 R15: 0000200000000680
 </TASK>
------------[ cut here ]------------
EA inode 11 i_nlink=2
WARNING: CPU: 0 PID: 11856 at fs/ext4/xattr.c:1070 ext4_xattr_inode_update_ref+0x521/0x580 fs/ext4/xattr.c:1068
Modules linked in:
CPU: 0 PID: 11856 Comm: syz.0.898 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:ext4_xattr_inode_update_ref+0x521/0x580 fs/ext4/xattr.c:1068
Code: 24 50 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 31 43 9a ff 49 8b 37 48 c7 c7 00 d1 be 8a 44 89 f2 e8 cf 73 0d ff <0f> 0b 4c 8b 64 24 18 48 8b 5c 24 10 4c 8d 7c 24 60 e9 1f fe ff ff
RSP: 0018:ffffc9000447f220 EFLAGS: 00010246
RAX: a5b76dc5edf9a300 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9000d159000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000447f318 R08: ffffc9000447ee27 R09: 1ffff9200088fdc4
R10: dffffc0000000000 R11: fffff5200088fdc5 R12: ffff888077fc2ab0
R13: dffffc0000000000 R14: 0000000000000002 R15: ffff888077fc2b00
FS:  00007f8f94bdf6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056394f2a0fb0 CR3: 000000006373f000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1093 [inline]
 ext4_xattr_set_entry+0xcda/0x1e90 fs/ext4/xattr.c:1731
 ext4_xattr_ibody_set+0x254/0x6a0 fs/ext4/xattr.c:2278
 ext4_xattr_move_to_block fs/ext4/xattr.c:2681 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2749 [inline]
 ext4_expand_extra_isize_ea+0x113a/0x19e0 fs/ext4/xattr.c:2841
 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5953
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5996 [inline]
 __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6074
 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:474
 __ext4_fill_super fs/ext4/super.c:5608 [inline]
 ext4_fill_super+0x5de7/0x66c0 fs/ext4/super.c:5731
 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:3377
 do_mount fs/namespace.c:3717 [inline]
 __do_sys_mount fs/namespace.c:3926 [inline]
 __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3903
 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
RIP: 0033:0x7f8f93d9034a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f8f94bdee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8f94bdeef0 RCX: 00007f8f93d9034a
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007f8f94bdeeb0
RBP: 0000200000000180 R08: 00007f8f94bdeef0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007f8f94bdeeb0 R14: 0000000000000473 R15: 0000200000000680
 </TASK>