====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.8.7121/27485 is trying to acquire lock: ffff888073490650 (sb_internal){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1891 [inline] ffff888073490650 (sb_internal){++++}-{0:0}, at: sb_start_intwrite include/linux/fs.h:2013 [inline] ffff888073490650 (sb_internal){++++}-{0:0}, at: ext4_evict_inode+0x43c/0x1110 fs/ext4/inode.c:240 but task is already holding lock: ffff888078b84b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x2d7/0xe60 fs/ext4/migrate.c:437 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+0x44/0x1a0 include/linux/percpu-rwsem.h:51 ext4_writepages+0x20f/0x2f40 fs/ext4/inode.c:2715 do_writepages+0x3ba/0x640 mm/page-writeback.c:2491 __writeback_single_inode+0x156/0x1160 fs/fs-writeback.c:1622 writeback_single_inode+0x3cb/0x8e0 fs/fs-writeback.c:1743 write_inode_now+0x17f/0x210 fs/fs-writeback.c:2780 iput_final fs/inode.c:1821 [inline] iput+0x613/0x980 fs/inode.c:1860 ext4_xattr_block_set+0x273b/0x32b0 fs/ext4/xattr.c:2145 ext4_xattr_move_to_block fs/ext4/xattr.c:2610 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2685 [inline] ext4_expand_extra_isize_ea+0x120b/0x1dc0 fs/ext4/xattr.c:2773 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5984 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6027 [inline] __ext4_mark_inode_dirty+0x47f/0x770 fs/ext4/inode.c:6105 ext4_evict_inode+0xa7f/0x1110 fs/ext4/inode.c:279 evict+0x4c9/0x8d0 fs/inode.c:705 ext4_orphan_cleanup+0xbeb/0x1420 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5556 [inline] ext4_fill_super+0x7829/0x7dc0 fs/ext4/super.c:5687 get_tree_bdev+0x3f1/0x610 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (sb_internal){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 percpu_down_read+0x44/0x1a0 include/linux/percpu-rwsem.h:51 __sb_start_write include/linux/fs.h:1891 [inline] sb_start_intwrite include/linux/fs.h:2013 [inline] ext4_evict_inode+0x43c/0x1110 fs/ext4/inode.c:240 evict+0x4c9/0x8d0 fs/inode.c:705 ext4_ext_migrate+0xc0c/0xe60 fs/ext4/migrate.c:587 __ext4_ioctl fs/ext4/ioctl.c:1396 [inline] ext4_ioctl+0x1eb1/0x4110 fs/ext4/ioctl.c:1614 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/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(&sbi->s_writepages_rwsem); lock(sb_internal); lock(&sbi->s_writepages_rwsem); lock(sb_internal); *** DEADLOCK *** 3 locks held by syz.8.7121/27485: #0: ffff888073490460 (sb_writers#4){++++}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:446 #1: ffff88803bc9d440 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff88803bc9d440 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: __ext4_ioctl fs/ext4/ioctl.c:1395 [inline] #1: ffff88803bc9d440 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_ioctl+0x1ea9/0x4110 fs/ext4/ioctl.c:1614 #2: ffff888078b84b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x2d7/0xe60 fs/ext4/migrate.c:437 stack backtrace: CPU: 1 PID: 27485 Comm: syz.8.7121 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 percpu_down_read+0x44/0x1a0 include/linux/percpu-rwsem.h:51 __sb_start_write include/linux/fs.h:1891 [inline] sb_start_intwrite include/linux/fs.h:2013 [inline] ext4_evict_inode+0x43c/0x1110 fs/ext4/inode.c:240 evict+0x4c9/0x8d0 fs/inode.c:705 ext4_ext_migrate+0xc0c/0xe60 fs/ext4/migrate.c:587 __ext4_ioctl fs/ext4/ioctl.c:1396 [inline] ext4_ioctl+0x1eb1/0x4110 fs/ext4/ioctl.c:1614 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8e8b19aeb9 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:00007f8e8bf9c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f8e8b415fa0 RCX: 00007f8e8b19aeb9 RDX: 0000000000000000 RSI: 0000000000006609 RDI: 0000000000000004 RBP: 00007f8e8b208c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8e8b416038 R14: 00007f8e8b415fa0 R15: 00007fff242df1f8