loop8: detected capacity change from 0 to 512
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.8.8368/30910 is trying to acquire lock:
ffff88805223ebd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline]
ffff88805223ebd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2806

but task is already holding lock:
ffff88804fcb80c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:165 [inline]
ffff88804fcb80c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6011 [inline]
ffff88804fcb80c8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3dc/0x6e0 fs/ext4/inode.c:6092

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ei->xattr_sem){++++}-{3:3}:
       down_write+0x97/0x200 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:1894
       ext4_do_writepages+0x4f0/0x3990 fs/ext4/inode.c:2604
       ext4_writepages+0x1dd/0x350 fs/ext4/inode.c:2807
       do_writepages+0x3b3/0x630 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_convert_inline_data+0x18f/0x5f0 fs/ext4/inline.c:2061
       ext4_fallocate+0xfb/0x1d80 fs/ext4/extents.c:4751
       vfs_fallocate+0x58e/0x700 fs/open.c:324
       ioctl_preallocate fs/ioctl.c:291 [inline]
       file_ioctl fs/ioctl.c:331 [inline]
       do_vfs_ioctl+0x19f6/0x1cc0 fs/ioctl.c:850
       __do_sys_ioctl fs/ioctl.c:869 [inline]
       __se_sys_ioctl+0x83/0x170 fs/ioctl.c:857
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
       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+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
       lock_acquire+0x19e/0x420 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+0x1a4/0x350 fs/ext4/inode.c:2806
       do_writepages+0x3b3/0x630 mm/page-writeback.c:2575
       __writeback_single_inode+0x153/0xec0 fs/fs-writeback.c:1635
       writeback_single_inode+0x21f/0x760 fs/fs-writeback.c:1756
       write_inode_now+0x183/0x210 fs/fs-writeback.c:2802
       iput_final fs/inode.c:1807 [inline]
       iput+0x5ae/0x920 fs/inode.c:1846
       ext4_xattr_block_set+0x273f/0x32b0 fs/ext4/xattr.c:2198
       ext4_xattr_move_to_block fs/ext4/xattr.c:2663 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2738 [inline]
       ext4_expand_extra_isize_ea+0x12c5/0x1e80 fs/ext4/xattr.c:2826
       __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5971
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:6014 [inline]
       __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6092
       ext4_evict_inode+0x7f3/0xea0 fs/ext4/inode.c:252
       evict+0x4ca/0x8d0 fs/inode.c:705
       ext4_orphan_cleanup+0xbec/0x1420 fs/ext4/orphan.c:472
       __ext4_fill_super fs/ext4/super.c:5617 [inline]
       ext4_fill_super+0x5ed3/0x6790 fs/ext4/super.c:5740
       get_tree_bdev+0x3f3/0x520 fs/super.c:1591
       vfs_get_tree+0x8c/0x280 fs/super.c:1764
       do_new_mount+0x24b/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+0x55/0xa0 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(&ei->xattr_sem);
                               lock(&sbi->s_writepages_rwsem);
                               lock(&ei->xattr_sem);
  rlock(&sbi->s_writepages_rwsem);

 *** DEADLOCK ***

3 locks held by syz.8.8368/30910:
 #0: ffff88805223c0e0 (&type->s_umount_key#31){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88805223c0e0 (&type->s_umount_key#31){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88805223c0e0 (&type->s_umount_key#31){++++}-{3:3}, at: get_tree_bdev+0x353/0x520 fs/super.c:1589
 #1: ffff88805223c608 (sb_internal){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff88805223c608 (sb_internal){++++}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1755 [inline]
 #1: ffff88805223c608 (sb_internal){++++}-{0:0}, at: ext4_evict_inode+0x2bf/0xea0 fs/ext4/inode.c:213
 #2: ffff88804fcb80c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:165 [inline]
 #2: ffff88804fcb80c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6011 [inline]
 #2: ffff88804fcb80c8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3dc/0x6e0 fs/ext4/inode.c:6092

stack backtrace:
CPU: 0 PID: 30910 Comm: syz.8.8368 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 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+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 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+0x1a4/0x350 fs/ext4/inode.c:2806
 do_writepages+0x3b3/0x630 mm/page-writeback.c:2575
 __writeback_single_inode+0x153/0xec0 fs/fs-writeback.c:1635
 writeback_single_inode+0x21f/0x760 fs/fs-writeback.c:1756
 write_inode_now+0x183/0x210 fs/fs-writeback.c:2802
 iput_final fs/inode.c:1807 [inline]
 iput+0x5ae/0x920 fs/inode.c:1846
 ext4_xattr_block_set+0x273f/0x32b0 fs/ext4/xattr.c:2198
 ext4_xattr_move_to_block fs/ext4/xattr.c:2663 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2738 [inline]
 ext4_expand_extra_isize_ea+0x12c5/0x1e80 fs/ext4/xattr.c:2826
 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5971
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6014 [inline]
 __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6092
 ext4_evict_inode+0x7f3/0xea0 fs/ext4/inode.c:252
 evict+0x4ca/0x8d0 fs/inode.c:705
 ext4_orphan_cleanup+0xbec/0x1420 fs/ext4/orphan.c:472
 __ext4_fill_super fs/ext4/super.c:5617 [inline]
 ext4_fill_super+0x5ed3/0x6790 fs/ext4/super.c:5740
 get_tree_bdev+0x3f3/0x520 fs/super.c:1591
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/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+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9bd879c14a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9bd9733e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9bd9733ee0 RCX: 00007f9bd879c14a
RDX: 0000200000000000 RSI: 00002000000001c0 RDI: 00007f9bd9733ea0
RBP: 0000200000000000 R08: 00007f9bd9733ee0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007f9bd9733ea0 R14: 000000000000046f R15: 00002000000007c0
 </TASK>
------------[ cut here ]------------
EA inode 11 i_nlink=0
WARNING: CPU: 0 PID: 30910 at fs/ext4/xattr.c:1058 ext4_xattr_inode_update_ref+0x51a/0x570 fs/ext4/xattr.c:1056
Modules linked in:
CPU: 0 PID: 30910 Comm: syz.8.8368 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:ext4_xattr_inode_update_ref+0x51a/0x570 fs/ext4/xattr.c:1056
Code: 8d 7e 50 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ff e8 67 ee 98 ff 49 8b 37 48 c7 c7 a0 d4 de 8a 89 da e8 66 8b 0a ff <0f> 0b 4c 8b 74 24 08 4c 8b 7c 24 10 e9 ab fe ff ff e8 90 be 3d 08
RSP: 0018:ffffc900052c71a0 EFLAGS: 00010246
RAX: 6545ecf52f488e00 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc90012520000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900052c7298 R08: ffffc900052c6da7 R09: 1ffff92000a58db4
R10: dffffc0000000000 R11: fffff52000a58db5 R12: dffffc0000000000
R13: ffff88805b2fe8a8 R14: ffff88805b2fe6b0 R15: ffff88805b2fe700
FS:  00007f9bd97346c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562c68c6a168 CR3: 000000005cdfe000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000c3ad8d DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1081 [inline]
 ext4_xattr_set_entry+0xcda/0x1e90 fs/ext4/xattr.c:1723
 ext4_xattr_ibody_set+0x254/0x6a0 fs/ext4/xattr.c:2267
 ext4_xattr_move_to_block fs/ext4/xattr.c:2670 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2738 [inline]
 ext4_expand_extra_isize_ea+0x1398/0x1e80 fs/ext4/xattr.c:2826
 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5971
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6014 [inline]
 __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6092
 ext4_evict_inode+0x7f3/0xea0 fs/ext4/inode.c:252
 evict+0x4ca/0x8d0 fs/inode.c:705
 ext4_orphan_cleanup+0xbec/0x1420 fs/ext4/orphan.c:472
 __ext4_fill_super fs/ext4/super.c:5617 [inline]
 ext4_fill_super+0x5ed3/0x6790 fs/ext4/super.c:5740
 get_tree_bdev+0x3f3/0x520 fs/super.c:1591
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/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+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9bd879c14a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9bd9733e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9bd9733ee0 RCX: 00007f9bd879c14a
RDX: 0000200000000000 RSI: 00002000000001c0 RDI: 00007f9bd9733ea0
RBP: 0000200000000000 R08: 00007f9bd9733ee0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007f9bd9733ea0 R14: 000000000000046f R15: 00002000000007c0
 </TASK>