loop2: detected capacity change from 0 to 512
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.310/5882 is trying to acquire lock:
ffff88807f51ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1c0/0x2e50 fs/ext4/inode.c:2715

but task is already holding lock:
ffff88805540bcf8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
ffff88805540bcf8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6006 [inline]
ffff88805540bcf8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3fe/0x770 fs/ext4/inode.c:6087

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ei->xattr_sem){++++}-{3:3}:
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
       ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1912
       ext4_writepages+0x5df/0x2e50 fs/ext4/inode.c:2761
       do_writepages+0x3b7/0x610 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+0x137/0x200 mm/filemap.c:774
       ext4_sync_file+0x23b/0xca0 fs/ext4/fsync.c:151
       generic_write_sync include/linux/fs.h:2962 [inline]
       ext4_buffered_write_iter+0x347/0x3e0 fs/ext4/file.c:292
       ext4_file_write_iter+0x1d6/0x16e0 fs/ext4/file.c:-1
       do_iter_readv_writev fs/read_write.c:-1 [inline]
       do_iter_write+0x62d/0xaf0 fs/read_write.c:861
       iter_file_splice_write+0x665/0xc50 fs/splice.c:685
       do_splice_from fs/splice.c:763 [inline]
       direct_splice_actor+0xe1/0x130 fs/splice.c:950
       splice_direct_to_actor+0x480/0xb60 fs/splice.c:896
       do_splice_direct+0x1b0/0x2b0 fs/splice.c:1002
       do_sendfile+0x5cc/0xeb0 fs/read_write.c:1255
       __do_sys_sendfile64 fs/read_write.c:1323 [inline]
       __se_sys_sendfile64+0x13b/0x190 fs/read_write.c:1309
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 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:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
       lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
       percpu_down_read+0x44/0x1a0 include/linux/percpu-rwsem.h:51
       ext4_writepages+0x1c0/0x2e50 fs/ext4/inode.c:2715
       do_writepages+0x3b7/0x610 mm/page-writeback.c:2491
       __writeback_single_inode+0x156/0x1160 fs/fs-writeback.c:1612
       writeback_single_inode+0x221/0x8b0 fs/fs-writeback.c:1733
       write_inode_now+0x15d/0x1d0 fs/fs-writeback.c:2770
       iput_final fs/inode.c:1821 [inline]
       iput+0x613/0x980 fs/inode.c:1860
       ext4_xattr_block_set+0x2736/0x32a0 fs/ext4/xattr.c:2157
       ext4_xattr_move_to_block fs/ext4/xattr.c:2625 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2700 [inline]
       ext4_expand_extra_isize_ea+0x109b/0x19b0 fs/ext4/xattr.c:2792
       __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5966
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:6009 [inline]
       __ext4_mark_inode_dirty+0x47f/0x770 fs/ext4/inode.c:6087
       ext4_evict_inode+0xa73/0x1100 fs/ext4/inode.c:279
       evict+0x485/0x870 fs/inode.c:705
       ext4_orphan_cleanup+0xbd3/0x1400 fs/ext4/orphan.c:474
       __ext4_fill_super fs/ext4/super.c:5537 [inline]
       ext4_fill_super+0x7bc2/0x8150 fs/ext4/super.c:5668
       get_tree_bdev+0x3f1/0x610 fs/super.c:1366
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x24a/0xa40 fs/namespace.c:3069
       do_mount fs/namespace.c:3412 [inline]
       __do_sys_mount fs/namespace.c:3620 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3597
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 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);
  lock(&sbi->s_writepages_rwsem);

 *** DEADLOCK ***

3 locks held by syz.2.310/5882:
 #0: ffff88807cc6a0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x930 fs/super.c:228
 #1: ffff88807cc6a650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1891 [inline]
 #1: ffff88807cc6a650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:2013 [inline]
 #1: ffff88807cc6a650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x436/0x1100 fs/ext4/inode.c:240
 #2: ffff88805540bcf8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
 #2: ffff88805540bcf8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6006 [inline]
 #2: ffff88805540bcf8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3fe/0x770 fs/ext4/inode.c:6087

stack backtrace:
CPU: 1 PID: 5882 Comm: syz.2.310 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 percpu_down_read+0x44/0x1a0 include/linux/percpu-rwsem.h:51
 ext4_writepages+0x1c0/0x2e50 fs/ext4/inode.c:2715
 do_writepages+0x3b7/0x610 mm/page-writeback.c:2491
 __writeback_single_inode+0x156/0x1160 fs/fs-writeback.c:1612
 writeback_single_inode+0x221/0x8b0 fs/fs-writeback.c:1733
 write_inode_now+0x15d/0x1d0 fs/fs-writeback.c:2770
 iput_final fs/inode.c:1821 [inline]
 iput+0x613/0x980 fs/inode.c:1860
 ext4_xattr_block_set+0x2736/0x32a0 fs/ext4/xattr.c:2157
 ext4_xattr_move_to_block fs/ext4/xattr.c:2625 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2700 [inline]
 ext4_expand_extra_isize_ea+0x109b/0x19b0 fs/ext4/xattr.c:2792
 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5966
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6009 [inline]
 __ext4_mark_inode_dirty+0x47f/0x770 fs/ext4/inode.c:6087
 ext4_evict_inode+0xa73/0x1100 fs/ext4/inode.c:279
 evict+0x485/0x870 fs/inode.c:705
 ext4_orphan_cleanup+0xbd3/0x1400 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5537 [inline]
 ext4_fill_super+0x7bc2/0x8150 fs/ext4/super.c:5668
 get_tree_bdev+0x3f1/0x610 fs/super.c:1366
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x24a/0xa40 fs/namespace.c:3069
 do_mount fs/namespace.c:3412 [inline]
 __do_sys_mount fs/namespace.c:3620 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3597
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7faf4b79034a
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:00007faf4c6dfe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007faf4c6dfef0 RCX: 00007faf4b79034a
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007faf4c6dfeb0
RBP: 0000200000000180 R08: 00007faf4c6dfef0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007faf4c6dfeb0 R14: 0000000000000473 R15: 0000200000000680
 </TASK>
------------[ cut here ]------------
EA inode 11 i_nlink=2
WARNING: CPU: 0 PID: 5882 at fs/ext4/xattr.c:1021 ext4_xattr_inode_update_ref+0x517/0x570 fs/ext4/xattr.c:1019
Modules linked in:
CPU: 0 PID: 5882 Comm: syz.2.310 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+0x517/0x570 fs/ext4/xattr.c:1019
Code: 7b 40 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ff e8 bb fa 9c ff 49 8b 37 48 c7 c7 60 9d a0 8a 44 89 f2 e8 d9 03 19 ff <0f> 0b 48 8b 5c 24 10 4c 8b 7c 24 18 4c 8d 6c 24 60 e9 00 fe ff ff
RSP: 0018:ffffc9000464f260 EFLAGS: 00010246
RAX: 3c804f9eb0066700 RBX: ffff888071ec16c0 RCX: 0000000000080000
RDX: ffffc9000cc82000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000464f348 R08: dffffc0000000000 R09: fffff520008c9ddd
R10: fffff520008c9ddd R11: 1ffff920008c9ddc R12: dffffc0000000000
R13: ffffc9000464f2c0 R14: 0000000000000002 R15: ffff888071ec1700
FS:  00007faf4c6e06c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f93b23a4198 CR3: 0000000076dd9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1044 [inline]
 ext4_xattr_set_entry+0xb33/0x1e90 fs/ext4/xattr.c:1682
 ext4_xattr_ibody_set+0x250/0x690 fs/ext4/xattr.c:2229
 ext4_xattr_move_to_block fs/ext4/xattr.c:2632 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2700 [inline]
 ext4_expand_extra_isize_ea+0x10e5/0x19b0 fs/ext4/xattr.c:2792
 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5966
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6009 [inline]
 __ext4_mark_inode_dirty+0x47f/0x770 fs/ext4/inode.c:6087
 ext4_evict_inode+0xa73/0x1100 fs/ext4/inode.c:279
 evict+0x485/0x870 fs/inode.c:705
 ext4_orphan_cleanup+0xbd3/0x1400 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5537 [inline]
 ext4_fill_super+0x7bc2/0x8150 fs/ext4/super.c:5668
 get_tree_bdev+0x3f1/0x610 fs/super.c:1366
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x24a/0xa40 fs/namespace.c:3069
 do_mount fs/namespace.c:3412 [inline]
 __do_sys_mount fs/namespace.c:3620 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3597
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7faf4b79034a
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:00007faf4c6dfe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007faf4c6dfef0 RCX: 00007faf4b79034a
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007faf4c6dfeb0
RBP: 0000200000000180 R08: 00007faf4c6dfef0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007faf4c6dfeb0 R14: 0000000000000473 R15: 0000200000000680
 </TASK>