====================================================== WARNING: possible circular locking dependency detected 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted ------------------------------------------------------ syz-executor.5/6047 is trying to acquire lock: ffffffff8e21f720 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:303 [inline] ffffffff8e21f720 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:3746 [inline] ffffffff8e21f720 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:3827 [inline] ffffffff8e21f720 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc+0x48/0x340 mm/slub.c:3852 but task is already holding lock: ffff88801f58d958 (&qinf->qi_tree_lock){+.+.}-{3:3}, at: xfs_qm_dqget_cache_insert fs/xfs/xfs_dquot.c:825 [inline] ffff88801f58d958 (&qinf->qi_tree_lock){+.+.}-{3:3}, at: xfs_qm_dqget+0x2c4/0x640 fs/xfs/xfs_dquot.c:901 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&qinf->qi_tree_lock){+.+.}-{3:3}: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 xfs_qm_dqfree_one+0x66/0x170 fs/xfs/xfs_qm.c:1654 xfs_qm_shrink_scan+0x33f/0x400 fs/xfs/xfs_qm.c:531 do_shrink_slab+0x6d2/0x1140 mm/shrinker.c:435 shrink_slab+0x1092/0x14d0 mm/shrinker.c:662 shrink_one+0x423/0x7f0 mm/vmscan.c:4767 shrink_many mm/vmscan.c:4828 [inline] lru_gen_shrink_node mm/vmscan.c:4929 [inline] shrink_node+0x37b8/0x3e70 mm/vmscan.c:5888 kswapd_shrink_node mm/vmscan.c:6696 [inline] balance_pgdat mm/vmscan.c:6886 [inline] kswapd+0x17d1/0x36e0 mm/vmscan.c:7146 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 -> #0 (fs_reclaim){+.+.}-{0:0}: 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+0x1e4/0x530 kernel/locking/lockdep.c:5754 __fs_reclaim_acquire mm/page_alloc.c:3692 [inline] fs_reclaim_acquire+0x88/0x130 mm/page_alloc.c:3706 might_alloc include/linux/sched/mm.h:303 [inline] slab_pre_alloc_hook mm/slub.c:3746 [inline] slab_alloc_node mm/slub.c:3827 [inline] kmem_cache_alloc+0x48/0x340 mm/slub.c:3852 radix_tree_node_alloc+0x8b/0x3c0 lib/radix-tree.c:276 radix_tree_extend+0x148/0x5c0 lib/radix-tree.c:425 __radix_tree_create lib/radix-tree.c:613 [inline] radix_tree_insert+0x15c/0x680 lib/radix-tree.c:712 xfs_qm_dqget_cache_insert fs/xfs/xfs_dquot.c:826 [inline] xfs_qm_dqget+0x2d4/0x640 fs/xfs/xfs_dquot.c:901 xfs_qm_vop_dqalloc+0x5a3/0xef0 fs/xfs/xfs_qm.c:1730 xfs_setattr_nonsize+0x410/0xea0 fs/xfs/xfs_iops.c:707 xfs_vn_setattr+0x2d1/0x320 fs/xfs/xfs_iops.c:1027 notify_change+0xb9f/0xe70 fs/attr.c:497 chown_common+0x501/0x850 fs/open.c:790 do_fchownat+0x16d/0x250 fs/open.c:821 __do_sys_chown fs/open.c:841 [inline] __se_sys_chown fs/open.c:839 [inline] __x64_sys_chown+0x82/0x90 fs/open.c:839 do_syscall_64+0xfd/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&qinf->qi_tree_lock); lock(fs_reclaim); lock(&qinf->qi_tree_lock); lock(fs_reclaim); *** DEADLOCK *** 3 locks held by syz-executor.5/6047: #0: ffff888028a02420 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 #1: ffff8880b4d650b8 (&inode->i_sb->s_type->i_mutex_dir_key){++++}-{3:3}, at: inode_lock include/linux/fs.h:793 [inline] #1: ffff8880b4d650b8 (&inode->i_sb->s_type->i_mutex_dir_key){++++}-{3:3}, at: chown_common+0x3e1/0x850 fs/open.c:780 #2: ffff88801f58d958 (&qinf->qi_tree_lock){+.+.}-{3:3}, at: xfs_qm_dqget_cache_insert fs/xfs/xfs_dquot.c:825 [inline] #2: ffff88801f58d958 (&qinf->qi_tree_lock){+.+.}-{3:3}, at: xfs_qm_dqget+0x2c4/0x640 fs/xfs/xfs_dquot.c:901 stack backtrace: CPU: 0 PID: 6047 Comm: syz-executor.5 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 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+0x1e4/0x530 kernel/locking/lockdep.c:5754 __fs_reclaim_acquire mm/page_alloc.c:3692 [inline] fs_reclaim_acquire+0x88/0x130 mm/page_alloc.c:3706 might_alloc include/linux/sched/mm.h:303 [inline] slab_pre_alloc_hook mm/slub.c:3746 [inline] slab_alloc_node mm/slub.c:3827 [inline] kmem_cache_alloc+0x48/0x340 mm/slub.c:3852 radix_tree_node_alloc+0x8b/0x3c0 lib/radix-tree.c:276 radix_tree_extend+0x148/0x5c0 lib/radix-tree.c:425 __radix_tree_create lib/radix-tree.c:613 [inline] radix_tree_insert+0x15c/0x680 lib/radix-tree.c:712 xfs_qm_dqget_cache_insert fs/xfs/xfs_dquot.c:826 [inline] xfs_qm_dqget+0x2d4/0x640 fs/xfs/xfs_dquot.c:901 xfs_qm_vop_dqalloc+0x5a3/0xef0 fs/xfs/xfs_qm.c:1730 xfs_setattr_nonsize+0x410/0xea0 fs/xfs/xfs_iops.c:707 xfs_vn_setattr+0x2d1/0x320 fs/xfs/xfs_iops.c:1027 notify_change+0xb9f/0xe70 fs/attr.c:497 chown_common+0x501/0x850 fs/open.c:790 do_fchownat+0x16d/0x250 fs/open.c:821 __do_sys_chown fs/open.c:841 [inline] __se_sys_chown fs/open.c:839 [inline] __x64_sys_chown+0x82/0x90 fs/open.c:839 do_syscall_64+0xfd/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fe9a027dda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe99f5ff0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000005c RAX: ffffffffffffffda RBX: 00007fe9a03abf80 RCX: 00007fe9a027dda9 RDX: 0000000039323420 RSI: 000000000000ee00 RDI: 0000000020000140 RBP: 00007fe9a02ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fe9a03abf80 R15: 00007ffd68c11948