WARNING: possible circular locking dependency detected 5.12.0-rc1-syzkaller #0 Not tainted ------------------------------------------------------ kswapd0/2210 is trying to acquire lock: ffff8880434568e0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xf86/0x1380 fs/jbd2/transaction.c:444 but task is already holding lock: ffffffff8c08bfc0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x30 mm/page_alloc.c:5198 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire mm/page_alloc.c:4327 [inline] fs_reclaim_acquire+0x117/0x150 mm/page_alloc.c:4341 prepare_alloc_pages mm/page_alloc.c:4939 [inline] __alloc_pages_nodemask+0x169/0x730 mm/page_alloc.c:4986 __alloc_pages include/linux/gfp.h:525 [inline] __alloc_pages_node include/linux/gfp.h:538 [inline] alloc_pages_node include/linux/gfp.h:552 [inline] kmalloc_large_node+0x5e/0x110 mm/slub.c:4069 __kmalloc_node+0x2c6/0x370 mm/slub.c:4085 kmalloc_node include/linux/slab.h:577 [inline] kvmalloc_node+0xb4/0xf0 mm/util.c:587 kvmalloc include/linux/mm.h:785 [inline] ext4_xattr_inode_cache_find fs/ext4/xattr.c:1465 [inline] ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1508 [inline] ext4_xattr_set_entry+0x1ce6/0x3750 fs/ext4/xattr.c:1649 ext4_xattr_ibody_set+0x78/0x2b0 fs/ext4/xattr.c:2224 ext4_xattr_set_handle+0x8f4/0x13e0 fs/ext4/xattr.c:2380 ext4_xattr_set+0x13a/0x340 fs/ext4/xattr.c:2493 __vfs_setxattr+0x115/0x180 fs/xattr.c:180 __vfs_setxattr_noperm+0x125/0x4c0 fs/xattr.c:214 __vfs_setxattr_locked+0x1cf/0x260 fs/xattr.c:274 vfs_setxattr+0x13f/0x330 fs/xattr.c:300 setxattr+0x218/0x2b0 fs/xattr.c:573 path_setxattr+0x197/0x1c0 fs/xattr.c:593 __do_sys_setxattr fs/xattr.c:609 [inline] __se_sys_setxattr fs/xattr.c:605 [inline] __ia32_sys_setxattr+0xbc/0x150 fs/xattr.c:605 do_syscall_32_irqs_on arch/x86/entry/common.c:77 [inline] __do_fast_syscall_32+0x56/0x80 arch/x86/entry/common.c:139 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:164 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c -> #1 (&ei->xattr_sem){++++}-{3:3}: down_read+0x9a/0x440 kernel/locking/rwsem.c:1353 ext4_setattr+0x57a/0x1fe0 fs/ext4/inode.c:5373 notify_change+0xb28/0x10f0 fs/attr.c:398 chown_common+0x501/0x5c0 fs/open.c:682 vfs_fchown fs/open.c:750 [inline] vfs_fchown fs/open.c:742 [inline] ksys_fchown+0x111/0x170 fs/open.c:761 __do_sys_fchown fs/open.c:769 [inline] __se_sys_fchown fs/open.c:767 [inline] __x64_sys_fchown+0x6f/0xb0 fs/open.c:767 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (jbd2_handle){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:2936 [inline] check_prevs_add kernel/locking/lockdep.c:3059 [inline] validate_chain kernel/locking/lockdep.c:3674 [inline] __lock_acquire+0x2b14/0x54c0 kernel/locking/lockdep.c:4900 lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 start_this_handle+0xfb9/0x1380 fs/jbd2/transaction.c:446 jbd2__journal_start+0x399/0x930 fs/jbd2/transaction.c:503 __ext4_journal_start_sb+0x227/0x4a0 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:320 [inline] ext4_dirty_inode+0x9d/0x110 fs/ext4/inode.c:5944 __mark_inode_dirty+0x6e3/0x10f0 fs/fs-writeback.c:2274 mark_inode_dirty_sync include/linux/fs.h:2272 [inline] iput.part.0+0x57/0x810 fs/inode.c:1677 iput+0x58/0x70 fs/inode.c:1670 dentry_unlink_inode+0x2b1/0x3d0 fs/dcache.c:374 __dentry_kill+0x3c0/0x640 fs/dcache.c:580 shrink_dentry_list+0x144/0x480 fs/dcache.c:1174 prune_dcache_sb+0xe7/0x140 fs/dcache.c:1255 super_cache_scan+0x336/0x590 fs/super.c:105 do_shrink_slab+0x3e4/0x9f0 mm/vmscan.c:512 shrink_slab+0x16f/0x5d0 mm/vmscan.c:673 shrink_node_memcgs mm/vmscan.c:2655 [inline] shrink_node+0x8d1/0x1de0 mm/vmscan.c:2770 kswapd_shrink_node mm/vmscan.c:3513 [inline] balance_pgdat+0x745/0x1270 mm/vmscan.c:3671 kswapd+0x5b6/0xdb0 mm/vmscan.c:3928 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 other info that might help us debug this: Chain exists of: jbd2_handle --> &ei->xattr_sem --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&ei->xattr_sem); lock(fs_reclaim); lock(jbd2_handle); *** DEADLOCK *** 3 locks held by kswapd0/2210: #0: ffffffff8c08bfc0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x30 mm/page_alloc.c:5198 #1: ffffffff8c053230 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0xc7/0x5d0 mm/vmscan.c:663 #2: ffff8880416260e0 ( &type->s_umount_key#38){++++}-{3:3}, at: trylock_super fs/super.c:418 [inline] &type->s_umount_key#38){++++}-{3:3}, at: super_cache_scan+0x6c/0x590 fs/super.c:80 stack backtrace: CPU: 3 PID: 2210 Comm: kswapd0 Not tainted 5.12.0-rc1-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0xfa/0x151 lib/dump_stack.c:120 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2127 check_prev_add kernel/locking/lockdep.c:2936 [inline] check_prevs_add kernel/locking/lockdep.c:3059 [inline] validate_chain kernel/locking/lockdep.c:3674 [inline] __lock_acquire+0x2b14/0x54c0 kernel/locking/lockdep.c:4900 lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 start_this_handle+0xfb9/0x1380 fs/jbd2/transaction.c:446 jbd2__journal_start+0x399/0x930 fs/jbd2/transaction.c:503 __ext4_journal_start_sb+0x227/0x4a0 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:320 [inline] ext4_dirty_inode+0x9d/0x110 fs/ext4/inode.c:5944 __mark_inode_dirty+0x6e3/0x10f0 fs/fs-writeback.c:2274 mark_inode_dirty_sync include/linux/fs.h:2272 [inline] iput.part.0+0x57/0x810 fs/inode.c:1677 iput+0x58/0x70 fs/inode.c:1670 dentry_unlink_inode+0x2b1/0x3d0 fs/dcache.c:374 __dentry_kill+0x3c0/0x640 fs/dcache.c:580 shrink_dentry_list+0x144/0x480 fs/dcache.c:1174 prune_dcache_sb+0xe7/0x140 fs/dcache.c:1255 super_cache_scan+0x336/0x590 fs/super.c:105 do_shrink_slab+0x3e4/0x9f0 mm/vmscan.c:512 shrink_slab+0x16f/0x5d0 mm/vmscan.c:673 shrink_node_memcgs mm/vmscan.c:2655 [inline] shrink_node+0x8d1/0x1de0 mm/vmscan.c:2770 kswapd_shrink_node mm/vmscan.c:3513 [inline] balance_pgdat+0x745/0x1270 mm/vmscan.c:3671 kswapd+0x5b6/0xdb0 mm/vmscan.c:3928 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294