====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.4.1375/13114 is trying to acquire lock: ffff8880596de600 (sb_internal){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] ffff8880596de600 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] ffff8880596de600 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs/super.h:177 [inline] ffff8880596de600 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x426/0x10e0 fs/ext4/inode.c:228 but task is already holding lock: ffff8880596dcc18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1827 [inline] ffff8880596dcc18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x308/0x1130 fs/ext4/migrate.c:438 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:1815 [inline] ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3030 do_writepages+0x32e/0x550 mm/page-writeback.c:2571 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1762 writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1881 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2972 iput_final fs/inode.c:1950 [inline] iput+0x8c1/0xe80 fs/inode.c:2009 ext4_xattr_block_set+0x2359/0x2ad0 fs/ext4/xattr.c:2151 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:6344 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6387 [inline] __ext4_mark_inode_dirty+0x45c/0x710 fs/ext4/inode.c:6465 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:5695 [inline] ext4_fill_super+0x5a19/0x6330 fs/ext4/super.c:5818 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:4399 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4376 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 (sb_internal){.+.+}-{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_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_intwrite include/linux/fs/super.h:177 [inline] ext4_evict_inode+0x426/0x10e0 fs/ext4/inode.c:228 evict+0x61e/0xb10 fs/inode.c:841 ext4_ext_migrate+0xe11/0x1130 fs/ext4/migrate.c:594 ext4_ioctl_setflags fs/ext4/ioctl.c:706 [inline] ext4_fileattr_set+0xf33/0x16d0 fs/ext4/ioctl.c:1027 vfs_fileattr_set+0x9f6/0xc90 fs/file_attr.c:301 ioctl_setflags+0x189/0x1f0 fs/file_attr.c:337 do_vfs_ioctl+0x9f1/0x1530 fs/ioctl.c:560 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 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(&sbi->s_writepages_rwsem); lock(sb_internal); lock(&sbi->s_writepages_rwsem); rlock(sb_internal); *** DEADLOCK *** 3 locks held by syz.4.1375/13114: #0: ffff8880596de410 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:537 #1: ffff888011d05148 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #1: ffff888011d05148 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: vfs_fileattr_set+0x161/0xc90 fs/file_attr.c:281 #2: ffff8880596dcc18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1827 [inline] #2: ffff8880596dcc18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x308/0x1130 fs/ext4/migrate.c:438 stack backtrace: CPU: 0 UID: 0 PID: 13114 Comm: syz.4.1375 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_intwrite include/linux/fs/super.h:177 [inline] ext4_evict_inode+0x426/0x10e0 fs/ext4/inode.c:228 evict+0x61e/0xb10 fs/inode.c:841 ext4_ext_migrate+0xe11/0x1130 fs/ext4/migrate.c:594 ext4_ioctl_setflags fs/ext4/ioctl.c:706 [inline] ext4_fileattr_set+0xf33/0x16d0 fs/ext4/ioctl.c:1027 vfs_fileattr_set+0x9f6/0xc90 fs/file_attr.c:301 ioctl_setflags+0x189/0x1f0 fs/file_attr.c:337 do_vfs_ioctl+0x9f1/0x1530 fs/ioctl.c:560 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 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: 0033:0x7f56a919c819 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:00007f56aa009028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f56a9416090 RCX: 00007f56a919c819 RDX: 0000200000000080 RSI: 0000000040086602 RDI: 0000000000000004 RBP: 00007f56a9232c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f56a9416128 R14: 00007f56a9416090 R15: 00007ffd67780be8