====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc5-syzkaller-00159-gc942a0cd3603 #0 Not tainted ------------------------------------------------------ kswapd0/88 is trying to acquire lock: ffff88805e8cce98 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_reclaim_inode fs/xfs/xfs_icache.c:945 [inline] ffff88805e8cce98 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1631 [inline] ffff88805e8cce98 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1713 but task is already holding lock: ffffffff8e428e80 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6782 [inline] ffffffff8e428e80 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xb20/0x30c0 mm/vmscan.c:7164 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __fs_reclaim_acquire mm/page_alloc.c:3698 [inline] fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3712 might_alloc include/linux/sched/mm.h:312 [inline] slab_pre_alloc_hook mm/slub.c:3746 [inline] slab_alloc_node mm/slub.c:3827 [inline] __do_kmalloc_node mm/slub.c:3965 [inline] __kmalloc+0xb7/0x4a0 mm/slub.c:3979 kmalloc include/linux/slab.h:632 [inline] xfs_attr_shortform_list+0x6f3/0x17a0 fs/xfs/xfs_attr_list.c:115 xfs_attr_list_ilocked fs/xfs/xfs_attr_list.c:527 [inline] xfs_attr_list+0x25b/0x350 fs/xfs/xfs_attr_list.c:547 xfs_vn_listxattr+0x1d2/0x2c0 fs/xfs/xfs_xattr.c:314 ovl_copy_xattr+0x174/0xb60 fs/overlayfs/copy_up.c:98 ovl_copy_up_metadata+0x24f/0xda0 fs/overlayfs/copy_up.c:650 ovl_copy_up_tmpfile fs/overlayfs/copy_up.c:870 [inline] ovl_do_copy_up fs/overlayfs/copy_up.c:976 [inline] ovl_copy_up_one fs/overlayfs/copy_up.c:1168 [inline] ovl_copy_up_flags+0x1eac/0x4450 fs/overlayfs/copy_up.c:1223 ovl_setattr+0x11d/0x5a0 fs/overlayfs/inode.c:41 notify_change+0xb9d/0xe70 fs/attr.c:497 chown_common+0x501/0x850 fs/open.c:790 vfs_fchown fs/open.c:858 [inline] ksys_fchown+0xea/0x160 fs/open.c:869 __do_sys_fchown fs/open.c:877 [inline] __se_sys_fchown fs/open.c:875 [inline] __x64_sys_fchown+0x7a/0x90 fs/open.c:875 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&xfs_nondir_ilock_class#3){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1695 xfs_reclaim_inode fs/xfs/xfs_icache.c:945 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1631 [inline] xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1713 xfs_icwalk fs/xfs/xfs_icache.c:1762 [inline] xfs_reclaim_inodes_nr+0x257/0x360 fs/xfs/xfs_icache.c:1011 super_cache_scan+0x40f/0x4b0 fs/super.c:227 do_shrink_slab+0x705/0x1160 mm/shrinker.c:435 shrink_slab+0x1092/0x14d0 mm/shrinker.c:662 shrink_node_memcgs mm/vmscan.c:5875 [inline] shrink_node+0x11f5/0x2d60 mm/vmscan.c:5908 kswapd_shrink_node mm/vmscan.c:6704 [inline] balance_pgdat mm/vmscan.c:6895 [inline] kswapd+0x1a25/0x30c0 mm/vmscan.c:7164 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&xfs_nondir_ilock_class#3); lock(fs_reclaim); lock(&xfs_nondir_ilock_class#3); *** DEADLOCK *** 2 locks held by kswapd0/88: #0: ffffffff8e428e80 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6782 [inline] #0: ffffffff8e428e80 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xb20/0x30c0 mm/vmscan.c:7164 #1: ffff8880957200e0 (&type->s_umount_key#100){++++}-{3:3}, at: super_trylock_shared fs/super.c:561 [inline] #1: ffff8880957200e0 (&type->s_umount_key#100){++++}-{3:3}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 0 PID: 88 Comm: kswapd0 Not tainted 6.9.0-rc5-syzkaller-00159-gc942a0cd3603 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1695 xfs_reclaim_inode fs/xfs/xfs_icache.c:945 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1631 [inline] xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1713 xfs_icwalk fs/xfs/xfs_icache.c:1762 [inline] xfs_reclaim_inodes_nr+0x257/0x360 fs/xfs/xfs_icache.c:1011 super_cache_scan+0x40f/0x4b0 fs/super.c:227 do_shrink_slab+0x705/0x1160 mm/shrinker.c:435 shrink_slab+0x1092/0x14d0 mm/shrinker.c:662 shrink_node_memcgs mm/vmscan.c:5875 [inline] shrink_node+0x11f5/0x2d60 mm/vmscan.c:5908 kswapd_shrink_node mm/vmscan.c:6704 [inline] balance_pgdat mm/vmscan.c:6895 [inline] kswapd+0x1a25/0x30c0 mm/vmscan.c:7164 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244