====================================================== WARNING: possible circular locking dependency detected 6.2.0-syzkaller-09238-gd2980d8d8265 #0 Not tainted ------------------------------------------------------ kswapd0/101 is trying to acquire lock: ffff888047a4c650 (sb_internal){.+.+}-{0:0}, at: evict+0x2ed/0x6b0 fs/inode.c:665 but task is already holding lock: ffffffff8c8e9a40 (fs_reclaim){+.+.}-{0:0}, at: set_task_reclaim_state mm/vmscan.c:200 [inline] ffffffff8c8e9a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x170/0x1ac0 mm/vmscan.c:7338 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire mm/page_alloc.c:4716 [inline] fs_reclaim_acquire+0x11d/0x160 mm/page_alloc.c:4730 might_alloc include/linux/sched/mm.h:271 [inline] slab_pre_alloc_hook mm/slab.h:728 [inline] slab_alloc_node mm/slub.c:3434 [inline] __kmem_cache_alloc_node+0x41/0x330 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:966 [inline] __kmalloc_node+0x4d/0xd0 mm/slab_common.c:974 kmalloc_node include/linux/slab.h:610 [inline] kvmalloc_node+0x76/0x1a0 mm/util.c:603 kvmalloc include/linux/slab.h:737 [inline] ext4_xattr_inode_cache_find fs/ext4/xattr.c:1500 [inline] ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1543 [inline] ext4_xattr_set_entry+0x1d82/0x39a0 fs/ext4/xattr.c:1685 ext4_xattr_block_set+0xcb7/0x3030 fs/ext4/xattr.c:1991 ext4_xattr_set_handle+0xd8a/0x1510 fs/ext4/xattr.c:2406 ext4_xattr_set+0x144/0x360 fs/ext4/xattr.c:2508 __vfs_setxattr+0x173/0x1e0 fs/xattr.c:203 __vfs_setxattr_noperm+0x129/0x5f0 fs/xattr.c:237 __vfs_setxattr_locked+0x1d3/0x260 fs/xattr.c:298 vfs_setxattr+0x143/0x340 fs/xattr.c:324 do_setxattr+0x147/0x190 fs/xattr.c:609 setxattr+0x146/0x160 fs/xattr.c:632 path_setxattr+0x197/0x1c0 fs/xattr.c:651 __do_sys_setxattr fs/xattr.c:667 [inline] __se_sys_setxattr fs/xattr.c:663 [inline] __ia32_sys_setxattr+0xc0/0x160 fs/xattr.c:663 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 -> #2 (&ei->xattr_sem){++++}-{3:3}: down_read+0x3d/0x50 kernel/locking/rwsem.c:1520 ext4_setattr+0xf7b/0x2590 fs/ext4/inode.c:5492 notify_change+0xb2c/0x1180 fs/attr.c:482 chown_common+0x57f/0x650 fs/open.c:738 do_fchownat+0x12a/0x1e0 fs/open.c:769 ksys_lchown include/linux/syscalls.h:1336 [inline] __do_sys_lchown16 kernel/uid16.c:30 [inline] __se_sys_lchown16 kernel/uid16.c:28 [inline] __ia32_sys_lchown16+0xe3/0x110 kernel/uid16.c:28 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 -> #1 (jbd2_handle){++++}-{0:0}: start_this_handle+0xfe7/0x14e0 fs/jbd2/transaction.c:463 jbd2__journal_start+0x39d/0x9d0 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x706/0x890 fs/ext4/ext4_jbd2.c:111 ext4_sample_last_mounted fs/ext4/file.c:841 [inline] ext4_file_open+0x618/0xbf0 fs/ext4/file.c:870 do_dentry_open+0x6cc/0x13f0 fs/open.c:884 do_open fs/namei.c:3560 [inline] path_openat+0x1baa/0x2750 fs/namei.c:3715 do_filp_open+0x1ba/0x410 fs/namei.c:3742 do_sys_openat2+0x16d/0x4c0 fs/open.c:1312 do_sys_open fs/open.c:1328 [inline] __do_sys_openat fs/open.c:1344 [inline] __se_sys_openat fs/open.c:1339 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1339 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (sb_internal){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1e3/0x670 kernel/locking/lockdep.c:5634 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1477 [inline] sb_start_intwrite include/linux/fs.h:1599 [inline] ext4_evict_inode+0xfc7/0x1b50 fs/ext4/inode.c:240 evict+0x2ed/0x6b0 fs/inode.c:665 iput_final fs/inode.c:1748 [inline] iput.part.0+0x59b/0x8a0 fs/inode.c:1774 iput+0x5c/0x80 fs/inode.c:1764 dentry_unlink_inode+0x2b1/0x460 fs/dcache.c:401 __dentry_kill+0x3c0/0x640 fs/dcache.c:607 shrink_dentry_list+0x12c/0x4f0 fs/dcache.c:1201 prune_dcache_sb+0xeb/0x150 fs/dcache.c:1282 super_cache_scan+0x33a/0x590 fs/super.c:104 do_shrink_slab+0x464/0xd20 mm/vmscan.c:853 shrink_slab_memcg mm/vmscan.c:922 [inline] shrink_slab+0x388/0x660 mm/vmscan.c:1001 shrink_one+0x502/0x810 mm/vmscan.c:5343 shrink_many mm/vmscan.c:5394 [inline] lru_gen_shrink_node mm/vmscan.c:5511 [inline] shrink_node+0x2064/0x35f0 mm/vmscan.c:6459 kswapd_shrink_node mm/vmscan.c:7262 [inline] balance_pgdat+0xa02/0x1ac0 mm/vmscan.c:7452 kswapd+0x70b/0x1000 mm/vmscan.c:7712 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 other info that might help us debug this: Chain exists of: sb_internal --> &ei->xattr_sem --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&ei->xattr_sem); lock(fs_reclaim); lock(sb_internal); *** DEADLOCK *** 3 locks held by kswapd0/101: #0: ffffffff8c8e9a40 (fs_reclaim){+.+.}-{0:0}, at: set_task_reclaim_state mm/vmscan.c:200 [inline] #0: ffffffff8c8e9a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x170/0x1ac0 mm/vmscan.c:7338 #1: ffffffff8c8a0630 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab_memcg mm/vmscan.c:895 [inline] #1: ffffffff8c8a0630 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x2a0/0x660 mm/vmscan.c:1001 #2: ffff888047a4c0e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super fs/super.c:414 [inline] #2: ffff888047a4c0e0 (&type->s_umount_key#32){++++}-{3:3}, at: super_cache_scan+0x70/0x590 fs/super.c:79 stack backtrace: CPU: 3 PID: 101 Comm: kswapd0 Not tainted 6.2.0-syzkaller-09238-gd2980d8d8265 #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:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1e3/0x670 kernel/locking/lockdep.c:5634 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1477 [inline] sb_start_intwrite include/linux/fs.h:1599 [inline] ext4_evict_inode+0xfc7/0x1b50 fs/ext4/inode.c:240 evict+0x2ed/0x6b0 fs/inode.c:665 iput_final fs/inode.c:1748 [inline] iput.part.0+0x59b/0x8a0 fs/inode.c:1774 iput+0x5c/0x80 fs/inode.c:1764 dentry_unlink_inode+0x2b1/0x460 fs/dcache.c:401 __dentry_kill+0x3c0/0x640 fs/dcache.c:607 shrink_dentry_list+0x12c/0x4f0 fs/dcache.c:1201 prune_dcache_sb+0xeb/0x150 fs/dcache.c:1282 super_cache_scan+0x33a/0x590 fs/super.c:104 do_shrink_slab+0x464/0xd20 mm/vmscan.c:853 shrink_slab_memcg mm/vmscan.c:922 [inline] shrink_slab+0x388/0x660 mm/vmscan.c:1001 shrink_one+0x502/0x810 mm/vmscan.c:5343 shrink_many mm/vmscan.c:5394 [inline] lru_gen_shrink_node mm/vmscan.c:5511 [inline] shrink_node+0x2064/0x35f0 mm/vmscan.c:6459 kswapd_shrink_node mm/vmscan.c:7262 [inline] balance_pgdat+0xa02/0x1ac0 mm/vmscan.c:7452 kswapd+0x70b/0x1000 mm/vmscan.c:7712 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308