====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.4.547/9474 is trying to acquire lock: ffff888047d7e0b8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff888047d7e0b8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1797 but task is already holding lock: ffff88805b590b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff88805b590b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1813 [inline] ffff88805b590b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}: 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: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+0x4ac/0xdc0 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:5670 [inline] ext4_fill_super+0x59ff/0x6320 fs/ext4/super.c:5793 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:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 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 (&ei->xattr_sem){++++}-{4:4}: 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 down_write+0x96/0x200 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1797 ext4_do_writepages+0x51e/0x46e0 fs/ext4/inode.c:2804 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3019 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 filemap_writeback mm/filemap.c:387 [inline] filemap_flush_range mm/filemap.c:436 [inline] filemap_flush+0x1e1/0x2e0 mm/filemap.c:451 ext4_convert_inline_data+0x18e/0x600 fs/ext4/inline.c:1964 ext4_fallocate+0x1e2/0x3d0 fs/ext4/extents.c:4848 vfs_fallocate+0x669/0x7e0 fs/open.c:340 ksys_fallocate fs/open.c:364 [inline] __do_sys_fallocate fs/open.c:369 [inline] __se_sys_fallocate fs/open.c:367 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:367 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 ---- ---- rlock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); *** DEADLOCK *** 3 locks held by syz.4.547/9474: #0: ffff88802885a420 (sb_writers#4){++++}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff88802885a420 (sb_writers#4){++++}-{0:0}, at: vfs_fallocate+0x5f0/0x7e0 fs/open.c:339 #1: ffff888047d7e3d0 (&sb->s_type->i_mutex_key#12){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888047d7e3d0 (&sb->s_type->i_mutex_key#12){++++}-{4:4}, at: ext4_fallocate+0x1da/0x3d0 fs/ext4/extents.c:4847 #2: ffff88805b590b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #2: ffff88805b590b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1813 [inline] #2: ffff88805b590b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3018 stack backtrace: CPU: 0 UID: 0 PID: 9474 Comm: syz.4.547 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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+0xf0/0x2e0 kernel/locking/lockdep.c:5868 down_write+0x96/0x200 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1797 ext4_do_writepages+0x51e/0x46e0 fs/ext4/inode.c:2804 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3019 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 filemap_writeback mm/filemap.c:387 [inline] filemap_flush_range mm/filemap.c:436 [inline] filemap_flush+0x1e1/0x2e0 mm/filemap.c:451 ext4_convert_inline_data+0x18e/0x600 fs/ext4/inline.c:1964 ext4_fallocate+0x1e2/0x3d0 fs/ext4/extents.c:4848 vfs_fallocate+0x669/0x7e0 fs/open.c:340 ksys_fallocate fs/open.c:364 [inline] __do_sys_fallocate fs/open.c:369 [inline] __se_sys_fallocate fs/open.c:367 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:367 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: 0033:0x7f68dd19bf79 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f68ddf74028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007f68dd416090 RCX: 00007f68dd19bf79 RDX: 0000000002000000 RSI: 0000000000000008 RDI: 0000000000000007 RBP: 00007f68dd2327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000010000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f68dd416128 R14: 00007f68dd416090 R15: 00007ffc705135f8 EXT4-fs error (device loop4): ext4_get_inode_loc:4920: inode #15: block 5: comm syz.4.547: unable to read itable block Buffer I/O error on dev loop4, logical block 0, lost sync page write EXT4-fs (loop4): I/O error while writing superblock EXT4-fs (loop4): Remounting filesystem read-only EXT4-fs (loop4): ext4_do_writepages: jbd2_start: 9223372036854775807 pages, ino 15; err -30