====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc1-syzkaller-00046-g7ec462100ef9 #0 Not tainted ------------------------------------------------------ kswapd0/74 is trying to acquire lock: ffff888012c29098 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_reclaim_inode fs/xfs/xfs_icache.c:981 [inline] ffff888012c29098 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1666 [inline] ffff888012c29098 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1748 but task is already holding lock: ffffffff8ea37160 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6844 [inline] ffffffff8ea37160 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x3700 mm/vmscan.c:7226 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:5825 __fs_reclaim_acquire mm/page_alloc.c:3834 [inline] fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3848 might_alloc include/linux/sched/mm.h:327 [inline] slab_pre_alloc_hook mm/slub.c:4037 [inline] slab_alloc_node mm/slub.c:4115 [inline] __do_kmalloc_node mm/slub.c:4264 [inline] __kmalloc_noprof+0xa9/0x400 mm/slub.c:4277 kmalloc_noprof include/linux/slab.h:882 [inline] xfs_attr_shortform_list+0x753/0x1900 fs/xfs/xfs_attr_list.c:117 xfs_attr_list+0x1d0/0x270 fs/xfs/xfs_attr_list.c:595 xfs_vn_listxattr+0x1d2/0x2c0 fs/xfs/xfs_xattr.c:341 ovl_copy_xattr+0x1a1/0xc10 fs/overlayfs/copy_up.c:98 ovl_copy_up_metadata+0x267/0xef0 fs/overlayfs/copy_up.c:669 ovl_copy_up_tmpfile fs/overlayfs/copy_up.c:894 [inline] ovl_do_copy_up fs/overlayfs/copy_up.c:1000 [inline] ovl_copy_up_one fs/overlayfs/copy_up.c:1203 [inline] ovl_copy_up_flags+0x21cb/0x46f0 fs/overlayfs/copy_up.c:1258 ovl_setattr+0x11d/0x5a0 fs/overlayfs/inode.c:40 notify_change+0xbca/0xe90 fs/attr.c:503 chmod_common+0x2ab/0x4c0 fs/open.c:653 do_fchmodat fs/open.c:701 [inline] __do_sys_fchmodat fs/open.c:720 [inline] __se_sys_fchmodat fs/open.c:717 [inline] __x64_sys_fchmodat+0x11d/0x1c0 fs/open.c:717 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 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:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693 xfs_reclaim_inode fs/xfs/xfs_icache.c:981 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1666 [inline] xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1748 xfs_icwalk fs/xfs/xfs_icache.c:1796 [inline] xfs_reclaim_inodes_nr+0x2ae/0x390 fs/xfs/xfs_icache.c:1047 super_cache_scan+0x40f/0x4b0 fs/super.c:227 do_shrink_slab+0x701/0x1160 mm/shrinker.c:435 shrink_slab+0x1093/0x14d0 mm/shrinker.c:662 shrink_one+0x43b/0x850 mm/vmscan.c:4818 shrink_many mm/vmscan.c:4879 [inline] lru_gen_shrink_node mm/vmscan.c:4957 [inline] shrink_node+0x3799/0x3de0 mm/vmscan.c:5937 kswapd_shrink_node mm/vmscan.c:6765 [inline] balance_pgdat mm/vmscan.c:6957 [inline] kswapd+0x1ca3/0x3700 mm/vmscan.c:7226 kthread+0x2f0/0x390 kernel/kthread.c:389 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 kswapd0/74: #0: ffffffff8ea37160 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6844 [inline] #0: ffffffff8ea37160 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x3700 mm/vmscan.c:7226 #1: ffff888011fc00e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff888011fc00e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 0 UID: 0 PID: 74 Comm: kswapd0 Not tainted 6.12.0-rc1-syzkaller-00046-g7ec462100ef9 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693 xfs_reclaim_inode fs/xfs/xfs_icache.c:981 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1666 [inline] xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1748 xfs_icwalk fs/xfs/xfs_icache.c:1796 [inline] xfs_reclaim_inodes_nr+0x2ae/0x390 fs/xfs/xfs_icache.c:1047 super_cache_scan+0x40f/0x4b0 fs/super.c:227 do_shrink_slab+0x701/0x1160 mm/shrinker.c:435 shrink_slab+0x1093/0x14d0 mm/shrinker.c:662 shrink_one+0x43b/0x850 mm/vmscan.c:4818 shrink_many mm/vmscan.c:4879 [inline] lru_gen_shrink_node mm/vmscan.c:4957 [inline] shrink_node+0x3799/0x3de0 mm/vmscan.c:5937 kswapd_shrink_node mm/vmscan.c:6765 [inline] balance_pgdat mm/vmscan.c:6957 [inline] kswapd+0x1ca3/0x3700 mm/vmscan.c:7226 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244