======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
syz.1.4217/24047 is trying to acquire lock:
ffff888060d4cc18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
ffff888060d4cc18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline]
ffff888060d4cc18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3041
but task is already holding lock:
ffff888092862fa0 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
ffff888092862fa0 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6474 [inline]
ffff888092862fa0 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3db/0x710 fs/ext4/inode.c:6555
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&ei->xattr_sem){++++}-{4:4}:
down_write+0x96/0x200 kernel/locking/rwsem.c:1625
ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline]
ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1805
ext4_do_writepages+0x51e/0x4670 fs/ext4/inode.c:2827
ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3042
do_writepages+0x32e/0x550 mm/page-writeback.c:2575
filemap_writeback mm/filemap.c:388 [inline]
filemap_fdatawrite_range mm/filemap.c:413 [inline]
file_write_and_wait_range+0x36e/0x440 mm/filemap.c:787
mmb_fsync_noflush+0x76/0x1c0 fs/buffer.c:645
ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline]
ext4_sync_file+0x437/0xd50 fs/ext4/fsync.c:160
generic_write_sync include/linux/fs.h:2654 [inline]
ext4_buffered_write_iter+0x2ca/0x3a0 fs/ext4/file.c:322
ext4_file_write_iter+0x298/0x1bf0 fs/ext4/file.c:-1
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61d/0xb90 fs/read_write.c:688
ksys_pwrite64 fs/read_write.c:795 [inline]
__do_sys_pwrite64 fs/read_write.c:803 [inline]
__se_sys_pwrite64 fs/read_write.c:800 [inline]
__x64_sys_pwrite64+0x199/0x230 fs/read_write.c:800
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&sbi->s_writepages_rwsem){++++}-{0:0}:
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+0x106/0x350 kernel/locking/lockdep.c:5868
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:1811 [inline]
ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3041
do_writepages+0x32e/0x550 mm/page-writeback.c:2575
__writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1883
write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2974
iput_final fs/inode.c:1950 [inline]
iput+0x8c1/0xe80 fs/inode.c:2009
ext4_xattr_block_set+0x1fd4/0x2ad0 fs/ext4/xattr.c:2206
ext4_xattr_move_to_block fs/ext4/xattr.c:2671 [inline]
ext4_xattr_make_inode_space fs/ext4/xattr.c:2746 [inline]
ext4_expand_extra_isize_ea+0x12cf/0x1ea0 fs/ext4/xattr.c:2834
__ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6434
ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline]
__ext4_mark_inode_dirty+0x45c/0x710 fs/ext4/inode.c:6555
ext4_evict_inode+0x986/0x10e0 fs/ext4/inode.c:267
evict+0x61e/0xb10 fs/inode.c:841
ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472
__ext4_fill_super fs/ext4/super.c:5701 [inline]
ext4_fill_super+0x5a19/0x6330 fs/ext4/super.c:5824
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:3758 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3834
do_mount fs/namespace.c:4167 [inline]
__do_sys_mount fs/namespace.c:4383 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4360
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/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
---- ----
lock(&ei->xattr_sem);
lock(&sbi->s_writepages_rwsem);
lock(&ei->xattr_sem);
rlock(&sbi->s_writepages_rwsem);
*** DEADLOCK ***
3 locks held by syz.1.4217/24047:
#0: ffff888034e080d8 (&type->s_umount_key#28/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:345
#1: ffff888034e08600 (sb_internal){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
#1: ffff888034e08600 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
#1: ffff888034e08600 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs/super.h:177 [inline]
#1: ffff888034e08600 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x426/0x10e0 fs/ext4/inode.c:228
#2: ffff888092862fa0 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
#2: ffff888092862fa0 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6474 [inline]
#2: ffff888092862fa0 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3db/0x710 fs/ext4/inode.c:6555
stack backtrace:
CPU: 1 UID: 0 PID: 24047 Comm: syz.1.4217 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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+0x106/0x350 kernel/locking/lockdep.c:5868
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:1811 [inline]
ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3041
do_writepages+0x32e/0x550 mm/page-writeback.c:2575
__writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1883
write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2974
iput_final fs/inode.c:1950 [inline]
iput+0x8c1/0xe80 fs/inode.c:2009
ext4_xattr_block_set+0x1fd4/0x2ad0 fs/ext4/xattr.c:2206
ext4_xattr_move_to_block fs/ext4/xattr.c:2671 [inline]
ext4_xattr_make_inode_space fs/ext4/xattr.c:2746 [inline]
ext4_expand_extra_isize_ea+0x12cf/0x1ea0 fs/ext4/xattr.c:2834
__ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6434
ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline]
__ext4_mark_inode_dirty+0x45c/0x710 fs/ext4/inode.c:6555
ext4_evict_inode+0x986/0x10e0 fs/ext4/inode.c:267
evict+0x61e/0xb10 fs/inode.c:841
ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472
__ext4_fill_super fs/ext4/super.c:5701 [inline]
ext4_fill_super+0x5a19/0x6330 fs/ext4/super.c:5824
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:3758 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3834
do_mount fs/namespace.c:4167 [inline]
__do_sys_mount fs/namespace.c:4383 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4360
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2fbff9e04a
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:00007f2fbe1ede58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2fbe1edee0 RCX: 00007f2fbff9e04a
RDX: 0000200000000180 RSI: 0000200000000040 RDI: 00007f2fbe1edea0
RBP: 0000200000000180 R08: 00007f2fbe1edee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f2fbe1edea0 R14: 0000000000000485 R15: 0000200000000b40
------------[ cut here ]------------
EA inode 11 i_nlink=65535
WARNING: fs/ext4/xattr.c:1059 at ext4_xattr_inode_update_ref+0x4c9/0x5a0 fs/ext4/xattr.c:1057, CPU#0: syz.1.4217/24047
Modules linked in:
CPU: 0 UID: 0 PID: 24047 Comm: syz.1.4217 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ext4_xattr_inode_update_ref+0x511/0x5a0 fs/ext4/xattr.c:1057
Code: 74 08 4c 89 ef e8 cf 5e 96 ff 4d 8b 6d 00 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 06 84 c0 75 77 41 8b 17 4c 89 e7 4c 89 ee <67> 48 0f b9 3a 4c 8b 6c 24 28 e9 59 fe ff ff e8 5b 8b 0d 09 44 89
RSP: 0018:ffffc900044c7100 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: dffffc0000000000
RDX: 000000000000ffff RSI: 000000000000000b RDI: ffffffff90375e20
RBP: ffffc900044c7200 R08: ffff8880928629a7 R09: 1ffff1101250c534
R10: dffffc0000000000 R11: ffffed101250c535 R12: ffffffff90375e20
R13: 000000000000000b R14: 1ffff1101250c500 R15: ffff888092862800
FS: 00007f2fbe1ee6c0(0000) GS:ffff888125290000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000011000 CR3: 000000008e30a000 CR4: 0000000000350ef0
Call Trace:
ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1082 [inline]
ext4_xattr_set_entry+0xabb/0x1e20 fs/ext4/xattr.c:1726
ext4_xattr_ibody_set+0x254/0x6a0 fs/ext4/xattr.c:2275
ext4_xattr_move_to_block fs/ext4/xattr.c:2678 [inline]
ext4_xattr_make_inode_space fs/ext4/xattr.c:2746 [inline]
ext4_expand_extra_isize_ea+0x13a2/0x1ea0 fs/ext4/xattr.c:2834
__ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6434
ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline]
__ext4_mark_inode_dirty+0x45c/0x710 fs/ext4/inode.c:6555
ext4_evict_inode+0x986/0x10e0 fs/ext4/inode.c:267
evict+0x61e/0xb10 fs/inode.c:841
ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472
__ext4_fill_super fs/ext4/super.c:5701 [inline]
ext4_fill_super+0x5a19/0x6330 fs/ext4/super.c:5824
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:3758 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3834
do_mount fs/namespace.c:4167 [inline]
__do_sys_mount fs/namespace.c:4383 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4360
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2fbff9e04a
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:00007f2fbe1ede58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2fbe1edee0 RCX: 00007f2fbff9e04a
RDX: 0000200000000180 RSI: 0000200000000040 RDI: 00007f2fbe1edea0
RBP: 0000200000000180 R08: 00007f2fbe1edee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f2fbe1edea0 R14: 0000000000000485 R15: 0000200000000b40
----------------
Code disassembly (best guess):
0: 74 08 je 0xa
2: 4c 89 ef mov %r13,%rdi
5: e8 cf 5e 96 ff call 0xff965ed9
a: 4d 8b 6d 00 mov 0x0(%r13),%r13
e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
15: fc ff df
18: 41 0f b6 04 06 movzbl (%r14,%rax,1),%eax
1d: 84 c0 test %al,%al
1f: 75 77 jne 0x98
21: 41 8b 17 mov (%r15),%edx
24: 4c 89 e7 mov %r12,%rdi
27: 4c 89 ee mov %r13,%rsi
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 4c 8b 6c 24 28 mov 0x28(%rsp),%r13
34: e9 59 fe ff ff jmp 0xfffffe92
39: e8 5b 8b 0d 09 call 0x90d8b99
3e: 44 rex.R
3f: 89 .byte 0x89