syzbot

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.30/6083 is trying to acquire lock:
ffff88803287ac58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
ffff88803287ac58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1813 [inline]
ffff88803287ac58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018

but task is already holding lock:
ffff88805c46eb98 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
ffff88805c46eb98 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6337 [inline]
ffff88805c46eb98 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3db/0x730 fs/ext4/inode.c:6418

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ei->xattr_sem){++++}-{4:4}:
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1590
       ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline]
       ext4_xattr_set_handle+0x19c/0x14c0 fs/ext4/xattr.c:2372
       ext4_initxattrs+0x9f/0x110 fs/ext4/xattr_security.c:44
       security_inode_init_security+0x296/0x3d0 security/security.c:1344
       __ext4_new_inode+0x332f/0x3d20 fs/ext4/ialloc.c:1324
       ext4_ext_migrate+0x740/0x1140 fs/ext4/migrate.c:462
       __ext4_ioctl fs/ext4/ioctl.c:1693 [inline]
       ext4_ioctl+0x2355/0x4b40 fs/ext4/ioctl.c:1922
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:597 [inline]
       __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/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+0xf0/0x2e0 kernel/locking/lockdep.c:5868
       percpu_down_read_internal+0x48/0x1d0 include/linux/percpu-rwsem.h:53
       percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
       ext4_writepages_down_read fs/ext4/ext4.h:1813 [inline]
       ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018
       do_writepages+0x32e/0x550 mm/page-writeback.c:2554
       __writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750
       writeback_single_inode+0x488/0xd60 fs/fs-writeback.c:1869
       write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2954
       iput_final fs/inode.c:1956 [inline]
       iput+0x8c1/0xe80 fs/inode.c:2015
       ext4_xattr_block_set+0x1fd4/0x2ad0 fs/ext4/xattr.c:2204
       ext4_xattr_move_to_block fs/ext4/xattr.c:2669 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2744 [inline]
       ext4_expand_extra_isize_ea+0x12cf/0x1ea0 fs/ext4/xattr.c:2832
       __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6297
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:6340 [inline]
       __ext4_mark_inode_dirty+0x45c/0x730 fs/ext4/inode.c:6418
       ext4_evict_inode+0x7a1/0xeb0 fs/ext4/inode.c:255
       evict+0x61e/0xb10 fs/inode.c:846
       ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472
       __ext4_fill_super fs/ext4/super.c:5668 [inline]
       ext4_fill_super+0x5a0b/0x6320 fs/ext4/super.c:5791
       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:3763 [inline]
       do_new_mount+0x341/0xd30 fs/namespace.c:3839
       do_mount fs/namespace.c:4172 [inline]
       __do_sys_mount fs/namespace.c:4361 [inline]
       __se_sys_mount+0x31d/0x420 fs/namespace.c:4338
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/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.0.30/6083:
 #0: ffff88803d29a0d0 (&type->s_umount_key#28/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345
 #1: ffff88803d29a770 (sb_internal){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 #1: ffff88803d29a770 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
 #1: ffff88803d29a770 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs/super.h:177 [inline]
 #1: ffff88803d29a770 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x274/0xeb0 fs/ext4/inode.c:216
 #2: ffff88805c46eb98 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
 #2: ffff88805c46eb98 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6337 [inline]
 #2: ffff88805c46eb98 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3db/0x730 fs/ext4/inode.c:6418

stack backtrace:
CPU: 1 UID: 0 PID: 6083 Comm: syz.0.30 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 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+0xf0/0x2e0 kernel/locking/lockdep.c:5868
 percpu_down_read_internal+0x48/0x1d0 include/linux/percpu-rwsem.h:53
 percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
 ext4_writepages_down_read fs/ext4/ext4.h:1813 [inline]
 ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018
 do_writepages+0x32e/0x550 mm/page-writeback.c:2554
 __writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750
 writeback_single_inode+0x488/0xd60 fs/fs-writeback.c:1869
 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2954
 iput_final fs/inode.c:1956 [inline]
 iput+0x8c1/0xe80 fs/inode.c:2015
 ext4_xattr_block_set+0x1fd4/0x2ad0 fs/ext4/xattr.c:2204
 ext4_xattr_move_to_block fs/ext4/xattr.c:2669 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2744 [inline]
 ext4_expand_extra_isize_ea+0x12cf/0x1ea0 fs/ext4/xattr.c:2832
 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6297
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6340 [inline]
 __ext4_mark_inode_dirty+0x45c/0x730 fs/ext4/inode.c:6418
 ext4_evict_inode+0x7a1/0xeb0 fs/ext4/inode.c:255
 evict+0x61e/0xb10 fs/inode.c:846
 ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472
 __ext4_fill_super fs/ext4/super.c:5668 [inline]
 ext4_fill_super+0x5a0b/0x6320 fs/ext4/super.c:5791
 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:3763 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3839
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4338
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f194e6fda0a
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:00007ffcab67c2d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcab67c360 RCX: 00007f194e6fda0a
RDX: 0000200000000180 RSI: 0000200000000000 RDI: 00007ffcab67c320
RBP: 0000200000000180 R08: 00007ffcab67c360 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000000
R13: 00007ffcab67c320 R14: 000000000000047a R15: 0000200000000b40
 </TASK>
EXT4-fs error (device loop0): ext4_xattr_inode_iget:441: inode #11: comm syz.0.30: iget: bad extra_isize 90 (inode size 256)
EXT4-fs error (device loop0): ext4_xattr_inode_iget:446: comm syz.0.30: error while reading EA inode 11 err=-117
loop0: lost filesystem error report for type 5 error -117
EXT4-fs warning (device loop0): ext4_expand_extra_isize_ea:2858: Unable to expand inode 15. Delete some EAs or run e2fsck.
EXT4-fs error (device loop0): ext4_xattr_inode_iget:441: inode #11: comm syz.0.30: iget: bad extra_isize 90 (inode size 256)
EXT4-fs error (device loop0): ext4_xattr_inode_iget:446: comm syz.0.30: error while reading EA inode 11 err=-117
loop0: lost filesystem error report for type 5 error -117
EXT4-fs error (device loop0): ext4_xattr_inode_iget:441: inode #18: comm syz.0.30: iget: bad extra_isize 90 (inode size 256)
EXT4-fs error (device loop0): ext4_xattr_inode_iget:446: comm syz.0.30: error while reading EA inode 18 err=-117
loop0: lost filesystem error report for type 5 error -117
EXT4-fs error (device loop0): ext4_xattr_inode_iget:441: inode #18: comm syz.0.30: iget: bad extra_isize 90 (inode size 256)
EXT4-fs error (device loop0): ext4_xattr_inode_iget:446: comm syz.0.30: error while reading EA inode 18 err=-117
loop0: lost filesystem error report for type 5 error -117
EXT4-fs (loop0): 1 orphan inode deleted
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000.