====================================================== WARNING: possible circular locking dependency detected 5.11.0-rc6-syzkaller #0 Not tainted ------------------------------------------------------ kswapd0/2246 is trying to acquire lock: ffff888041a988e0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xf81/0x1380 fs/jbd2/transaction.c:444 but task is already holding lock: ffffffff8be892c0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x30 mm/page_alloc.c:5195 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:4326 [inline] fs_reclaim_acquire+0x117/0x150 mm/page_alloc.c:4340 might_alloc include/linux/sched/mm.h:193 [inline] slab_pre_alloc_hook mm/slab.h:493 [inline] slab_alloc_node mm/slub.c:2817 [inline] __kmalloc_node+0x5f/0x430 mm/slub.c:4015 kmalloc_node include/linux/slab.h:575 [inline] kvmalloc_node+0x61/0xf0 mm/util.c:587 kvmalloc include/linux/mm.h:781 [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+0x1ce6/0x3780 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 ext4_xattr_user_set+0xbc/0x100 fs/ext4/xattr_user.c:40 __vfs_setxattr+0x10e/0x170 fs/xattr.c:177 __vfs_setxattr_noperm+0x11a/0x4c0 fs/xattr.c:208 __vfs_setxattr_locked+0x1bf/0x250 fs/xattr.c:266 vfs_setxattr+0x135/0x320 fs/xattr.c:291 setxattr+0x1ff/0x290 fs/xattr.c:553 path_setxattr+0x170/0x190 fs/xattr.c:572 __do_sys_setxattr fs/xattr.c:587 [inline] __se_sys_setxattr fs/xattr.c:583 [inline] __ia32_sys_setxattr+0xbc/0x150 fs/xattr.c:583 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+0x95/0x440 kernel/locking/rwsem.c:1353 ext4_setattr+0x570/0x1fd0 fs/ext4/inode.c:5375 notify_change+0xb60/0x10a0 fs/attr.c:336 chown_common+0x4a9/0x550 fs/open.c:674 vfs_fchown fs/open.c:741 [inline] vfs_fchown fs/open.c:733 [inline] ksys_fchown+0x111/0x170 fs/open.c:752 __do_sys_fchown fs/open.c:760 [inline] __se_sys_fchown fs/open.c:758 [inline] __x64_sys_fchown+0x6f/0xb0 fs/open.c:758 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (jbd2_handle){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:2868 [inline] check_prevs_add kernel/locking/lockdep.c:2993 [inline] validate_chain kernel/locking/lockdep.c:3608 [inline] __lock_acquire+0x2b26/0x54f0 kernel/locking/lockdep.c:4832 lock_acquire kernel/locking/lockdep.c:5442 [inline] lock_acquire+0x1a8/0x720 kernel/locking/lockdep.c:5407 start_this_handle+0xfb4/0x1380 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+0xbc/0x130 fs/ext4/inode.c:5951 __mark_inode_dirty+0x81f/0x1070 fs/fs-writeback.c:2262 mark_inode_dirty_sync include/linux/fs.h:2186 [inline] iput.part.0+0x57/0x810 fs/inode.c:1676 iput+0x58/0x70 fs/inode.c:1669 dentry_unlink_inode+0x2b1/0x3d0 fs/dcache.c:374 __dentry_kill+0x3c0/0x640 fs/dcache.c:579 shrink_dentry_list+0x144/0x480 fs/dcache.c:1148 prune_dcache_sb+0xe7/0x140 fs/dcache.c:1229 super_cache_scan+0x336/0x590 fs/super.c:105 do_shrink_slab+0x3e4/0x9f0 mm/vmscan.c:511 shrink_slab+0x16f/0x5d0 mm/vmscan.c:672 shrink_node_memcgs mm/vmscan.c:2665 [inline] shrink_node+0x8cc/0x1de0 mm/vmscan.c:2780 kswapd_shrink_node mm/vmscan.c:3523 [inline] balance_pgdat+0x745/0x1270 mm/vmscan.c:3681 kswapd+0x5b1/0xdb0 mm/vmscan.c:3938 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 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 kswapd0/2246: #0: ffffffff8be892c0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x30 mm/page_alloc.c:5195 #1: ffffffff8be507f0 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0xc7/0x5d0 mm/vmscan.c:662 #2: ffff8880442660e0 (&type->s_umount_key#38){++++}-{3:3}, at: trylock_super fs/super.c:418 [inline] #2: ffff8880442660e0 (&type->s_umount_key#38){++++}-{3:3}, at: super_cache_scan+0x6c/0x590 fs/super.c:80 stack backtrace: CPU: 0 PID: 2246 Comm: kswapd0 Not tainted 5.11.0-rc6-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+0x107/0x163 lib/dump_stack.c:120 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2117 check_prev_add kernel/locking/lockdep.c:2868 [inline] check_prevs_add kernel/locking/lockdep.c:2993 [inline] validate_chain kernel/locking/lockdep.c:3608 [inline] __lock_acquire+0x2b26/0x54f0 kernel/locking/lockdep.c:4832 lock_acquire kernel/locking/lockdep.c:5442 [inline] lock_acquire+0x1a8/0x720 kernel/locking/lockdep.c:5407 start_this_handle+0xfb4/0x1380 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+0xbc/0x130 fs/ext4/inode.c:5951 __mark_inode_dirty+0x81f/0x1070 fs/fs-writeback.c:2262 mark_inode_dirty_sync include/linux/fs.h:2186 [inline] iput.part.0+0x57/0x810 fs/inode.c:1676 iput+0x58/0x70 fs/inode.c:1669 dentry_unlink_inode+0x2b1/0x3d0 fs/dcache.c:374 __dentry_kill+0x3c0/0x640 fs/dcache.c:579 shrink_dentry_list+0x144/0x480 fs/dcache.c:1148 prune_dcache_sb+0xe7/0x140 fs/dcache.c:1229 super_cache_scan+0x336/0x590 fs/super.c:105 do_shrink_slab+0x3e4/0x9f0 mm/vmscan.c:511 shrink_slab+0x16f/0x5d0 mm/vmscan.c:672 shrink_node_memcgs mm/vmscan.c:2665 [inline] shrink_node+0x8cc/0x1de0 mm/vmscan.c:2780 kswapd_shrink_node mm/vmscan.c:3523 [inline] balance_pgdat+0x745/0x1270 mm/vmscan.c:3681 kswapd+0x5b1/0xdb0 mm/vmscan.c:3938 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296