====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.3.6743/30783 is trying to acquire lock: ffff88804c63b108 (&ht->mutex){+.+.}-{4:4}, at: rhashtable_free_and_destroy+0x49/0x9c0 lib/rhashtable.c:1180 but task is already holding lock: ffffffff8e9b08c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4398 [inline] ffffffff8e9b08c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4423 [inline] ffffffff8e9b08c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath mm/page_alloc.c:4823 [inline] ffffffff8e9b08c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_frozen_pages_noprof+0x1239/0x2bc0 mm/page_alloc.c:5239 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire mm/page_alloc.c:4325 [inline] fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4339 might_alloc include/linux/sched/mm.h:317 [inline] slab_pre_alloc_hook mm/slub.c:4520 [inline] slab_alloc_node mm/slub.c:4875 [inline] __do_kmalloc_node mm/slub.c:5294 [inline] __kvmalloc_node_noprof+0xcc/0xa00 mm/slub.c:6832 bucket_table_alloc.isra.0+0x88/0x460 lib/rhashtable.c:186 rhashtable_rehash_alloc+0x68/0x110 lib/rhashtable.c:368 rht_deferred_worker+0x1d9/0x1fd0 lib/rhashtable.c:429 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #0 (&ht->mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1b10 kernel/locking/mutex.c:820 rhashtable_free_and_destroy+0x49/0x9c0 lib/rhashtable.c:1180 kernfs_put.part.0+0x175/0x720 fs/kernfs/dir.c:609 kernfs_put+0x53/0x60 fs/kernfs/dir.c:629 evict+0x3c2/0xad0 fs/inode.c:841 iput_final fs/inode.c:1960 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2009 iput+0x35/0x40 fs/inode.c:1975 dentry_unlink_inode+0x2c0/0x4c0 fs/dcache.c:476 __dentry_kill+0x1d0/0x690 fs/dcache.c:718 shrink_kill fs/dcache.c:1195 [inline] shrink_dentry_list+0x180/0x5e0 fs/dcache.c:1222 prune_dcache_sb+0xea/0x150 fs/dcache.c:1304 super_cache_scan+0x328/0x550 fs/super.c:223 do_shrink_slab+0x416/0x1240 mm/shrinker.c:436 shrink_slab_memcg mm/shrinker.c:553 [inline] shrink_slab+0xa7d/0x12e0 mm/shrinker.c:631 shrink_one+0x398/0x7f0 mm/vmscan.c:5071 shrink_many mm/vmscan.c:5132 [inline] lru_gen_shrink_node mm/vmscan.c:5210 [inline] shrink_node+0x2673/0x3dc0 mm/vmscan.c:6198 shrink_zones mm/vmscan.c:6454 [inline] do_try_to_free_pages+0x33e/0x16d0 mm/vmscan.c:6516 try_to_free_pages+0x294/0x750 mm/vmscan.c:6755 __perform_reclaim mm/page_alloc.c:4401 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:4423 [inline] __alloc_pages_slowpath mm/page_alloc.c:4823 [inline] __alloc_frozen_pages_noprof+0x128f/0x2bc0 mm/page_alloc.c:5239 __alloc_pages_noprof mm/page_alloc.c:5260 [inline] __folio_alloc_noprof+0x13/0x260 mm/page_alloc.c:5270 alloc_migration_target+0x1d7/0x6d0 mm/migrate.c:2224 migrate_folio_unmap mm/migrate.c:1217 [inline] migrate_pages_batch+0x5dc/0x45c0 mm/migrate.c:1909 migrate_pages_sync+0x12c/0x880 mm/migrate.c:2026 migrate_pages+0x1aa5/0x2880 mm/migrate.c:2135 do_move_pages_to_node mm/migrate.c:2248 [inline] move_pages_and_store_status+0xf1/0x230 mm/migrate.c:2328 do_pages_move mm/migrate.c:2424 [inline] kernel_move_pages+0xc47/0x13f0 mm/migrate.c:2610 __do_sys_move_pages mm/migrate.c:2624 [inline] __se_sys_move_pages mm/migrate.c:2619 [inline] __ia32_sys_move_pages+0xdd/0x1b0 mm/migrate.c:2619 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x950 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&ht->mutex); lock(fs_reclaim); lock(&ht->mutex); *** DEADLOCK *** 2 locks held by syz.3.6743/30783: #0: ffffffff8e9b08c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4398 [inline] #0: ffffffff8e9b08c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4423 [inline] #0: ffffffff8e9b08c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath mm/page_alloc.c:4823 [inline] #0: ffffffff8e9b08c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_frozen_pages_noprof+0x1239/0x2bc0 mm/page_alloc.c:5239 #1: ffff8880502300d8 (&type->s_umount_key#52){++++}-{4:4}, at: super_trylock_shared fs/super.c:565 [inline] #1: ffff8880502300d8 (&type->s_umount_key#52){++++}-{4:4}, at: super_cache_scan+0x98/0x550 fs/super.c:198 stack backtrace: CPU: 0 UID: 0 PID: 30783 Comm: syz.3.6743 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1b10 kernel/locking/mutex.c:820 rhashtable_free_and_destroy+0x49/0x9c0 lib/rhashtable.c:1180 kernfs_put.part.0+0x175/0x720 fs/kernfs/dir.c:609 kernfs_put+0x53/0x60 fs/kernfs/dir.c:629 evict+0x3c2/0xad0 fs/inode.c:841 iput_final fs/inode.c:1960 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2009 iput+0x35/0x40 fs/inode.c:1975 dentry_unlink_inode+0x2c0/0x4c0 fs/dcache.c:476 __dentry_kill+0x1d0/0x690 fs/dcache.c:718 shrink_kill fs/dcache.c:1195 [inline] shrink_dentry_list+0x180/0x5e0 fs/dcache.c:1222 prune_dcache_sb+0xea/0x150 fs/dcache.c:1304 super_cache_scan+0x328/0x550 fs/super.c:223 do_shrink_slab+0x416/0x1240 mm/shrinker.c:436 shrink_slab_memcg mm/shrinker.c:553 [inline] shrink_slab+0xa7d/0x12e0 mm/shrinker.c:631 shrink_one+0x398/0x7f0 mm/vmscan.c:5071 shrink_many mm/vmscan.c:5132 [inline] lru_gen_shrink_node mm/vmscan.c:5210 [inline] shrink_node+0x2673/0x3dc0 mm/vmscan.c:6198 shrink_zones mm/vmscan.c:6454 [inline] do_try_to_free_pages+0x33e/0x16d0 mm/vmscan.c:6516 try_to_free_pages+0x294/0x750 mm/vmscan.c:6755 __perform_reclaim mm/page_alloc.c:4401 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:4423 [inline] __alloc_pages_slowpath mm/page_alloc.c:4823 [inline] __alloc_frozen_pages_noprof+0x128f/0x2bc0 mm/page_alloc.c:5239 __alloc_pages_noprof mm/page_alloc.c:5260 [inline] __folio_alloc_noprof+0x13/0x260 mm/page_alloc.c:5270 alloc_migration_target+0x1d7/0x6d0 mm/migrate.c:2224 migrate_folio_unmap mm/migrate.c:1217 [inline] migrate_pages_batch+0x5dc/0x45c0 mm/migrate.c:1909 migrate_pages_sync+0x12c/0x880 mm/migrate.c:2026 migrate_pages+0x1aa5/0x2880 mm/migrate.c:2135 do_move_pages_to_node mm/migrate.c:2248 [inline] move_pages_and_store_status+0xf1/0x230 mm/migrate.c:2328 do_pages_move mm/migrate.c:2424 [inline] kernel_move_pages+0xc47/0x13f0 mm/migrate.c:2610 __do_sys_move_pages mm/migrate.c:2624 [inline] __se_sys_move_pages mm/migrate.c:2619 [inline] __ia32_sys_move_pages+0xdd/0x1b0 mm/migrate.c:2619 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x950 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf6feefcc Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 2e 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 58 b8 RSP: 002b:00000000f53dd50c EFLAGS: 00000292 ORIG_RAX: 000000000000013d RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000002064 RDX: 0000000080000040 RSI: 0000000080001180 RDI: 0000000080000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: d2 74 05 c1 shlb %cl,-0x3f(%rbp,%rax,1) 4: e8 0c 89 02 8b call 0x8b028915 9: 5d pop %rbp a: fc cld b: 31 c0 xor %eax,%eax d: c9 leave e: c3 ret f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 0f 1f 00 nopl (%rax) 21: 51 push %rcx 22: 52 push %rdx 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 90 nop 2f: 2e 8d b4 26 00 00 00 cs lea 0x0(%rsi,%riz,1),%esi 36: 00 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 3e: 58 pop %rax 3f: b8 .byte 0xb8