====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc5-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/10525 is trying to acquire lock: ffff88803fffece0 (&pgdat->kswapd_wait){....}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:105 [inline] ffff88803fffece0 (&pgdat->kswapd_wait){....}-{2:2}, at: __wake_up+0x1c/0x60 kernel/sched/wait.c:127 but task is already holding lock: ffff8880210d39f8 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xca/0xda0 kernel/bpf/lpm_trie.c:324 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&trie->lock){....}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 trie_delete_elem+0xb0/0x7e0 kernel/bpf/lpm_trie.c:451 0xffffffffa0001f15 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run4+0x176/0x460 kernel/trace/bpf_trace.c:2422 __traceiter_sched_switch+0x6c/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x252c/0x5d00 kernel/sched/core.c:6743 schedule_idle+0x59/0x90 kernel/sched/core.c:6864 do_idle+0x287/0x3f0 kernel/sched/idle.c:360 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x220/0x2b0 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x148 -> #2 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 raw_spin_rq_lock kernel/sched/sched.h:1387 [inline] rq_lock kernel/sched/sched.h:1701 [inline] task_fork_fair+0x70/0x240 kernel/sched/fair.c:12635 sched_cgroup_fork+0x3cf/0x510 kernel/sched/core.c:4845 copy_process+0x450e/0x6f00 kernel/fork.c:2499 kernel_clone+0xfd/0x980 kernel/fork.c:2797 user_mode_thread+0xb4/0xf0 kernel/fork.c:2875 rest_init+0x23/0x2b0 init/main.c:704 start_kernel+0x3a3/0x490 init/main.c:1081 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x148 -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline] try_to_wake_up+0x9a/0x13e0 kernel/sched/core.c:4262 autoremove_wake_function+0x16/0x150 kernel/sched/wait.c:384 __wake_up_common+0x131/0x1e0 kernel/sched/wait.c:89 __wake_up_common_lock kernel/sched/wait.c:106 [inline] __wake_up+0x31/0x60 kernel/sched/wait.c:127 wakeup_kswapd+0x45e/0x640 mm/vmscan.c:7224 wake_all_kswapds+0x182/0x2e0 mm/page_alloc.c:3833 __alloc_pages_slowpath mm/page_alloc.c:4102 [inline] __alloc_pages+0x100f/0x2460 mm/page_alloc.c:4588 __folio_alloc+0x10/0x30 mm/page_alloc.c:4607 alloc_migration_target+0x31c/0x7e0 mm/migrate.c:2041 migrate_folio_unmap mm/migrate.c:1133 [inline] migrate_pages_batch+0x3a6/0x2c60 mm/migrate.c:1678 migrate_pages_sync mm/migrate.c:1844 [inline] migrate_pages+0x1bb2/0x2880 mm/migrate.c:1953 do_move_pages_to_node mm/migrate.c:2065 [inline] move_pages_and_store_status+0xf4/0x230 mm/migrate.c:2155 do_pages_move mm/migrate.c:2270 [inline] kernel_move_pages+0xc46/0x18f0 mm/migrate.c:2450 __do_sys_move_pages mm/migrate.c:2464 [inline] __se_sys_move_pages mm/migrate.c:2459 [inline] __ia32_sys_move_pages+0xdd/0x1b0 mm/migrate.c:2459 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #0 (&pgdat->kswapd_wait){....}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock kernel/sched/wait.c:105 [inline] __wake_up+0x1c/0x60 kernel/sched/wait.c:127 wakeup_kswapd+0x45e/0x640 mm/vmscan.c:7224 rmqueue mm/page_alloc.c:2919 [inline] get_page_from_freelist+0xda0/0x3780 mm/page_alloc.c:3314 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] __kmalloc_large_node+0x7f/0x1a0 mm/slub.c:3911 __do_kmalloc_node mm/slub.c:3954 [inline] __kmalloc_node.cold+0x5/0x5f mm/slub.c:3973 kmalloc_node include/linux/slab.h:648 [inline] bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline] trie_update_elem+0x1fc/0xda0 kernel/bpf/lpm_trie.c:333 bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203 generic_map_update_batch+0x454/0x5f0 kernel/bpf/syscall.c:1876 bpf_map_do_batch+0x615/0x6e0 kernel/bpf/syscall.c:5174 __sys_bpf+0x18ff/0x58b0 kernel/bpf/syscall.c:5724 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5765 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Chain exists of: &pgdat->kswapd_wait --> &rq->__lock --> &trie->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&trie->lock); lock(&rq->__lock); lock(&trie->lock); lock(&pgdat->kswapd_wait); *** DEADLOCK *** 2 locks held by syz-executor.1/10525: #0: ffffffff8d7b44e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8d7b44e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8d7b44e0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x24b/0x6c0 kernel/bpf/syscall.c:202 #1: ffff8880210d39f8 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xca/0xda0 kernel/bpf/lpm_trie.c:324 stack backtrace: CPU: 2 PID: 10525 Comm: syz-executor.1 Not tainted 6.9.0-rc5-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 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 kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock kernel/sched/wait.c:105 [inline] __wake_up+0x1c/0x60 kernel/sched/wait.c:127 wakeup_kswapd+0x45e/0x640 mm/vmscan.c:7224 rmqueue mm/page_alloc.c:2919 [inline] get_page_from_freelist+0xda0/0x3780 mm/page_alloc.c:3314 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] __kmalloc_large_node+0x7f/0x1a0 mm/slub.c:3911 __do_kmalloc_node mm/slub.c:3954 [inline] __kmalloc_node.cold+0x5/0x5f mm/slub.c:3973 kmalloc_node include/linux/slab.h:648 [inline] bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline] trie_update_elem+0x1fc/0xda0 kernel/bpf/lpm_trie.c:333 bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203 generic_map_update_batch+0x454/0x5f0 kernel/bpf/syscall.c:1876 bpf_map_do_batch+0x615/0x6e0 kernel/bpf/syscall.c:5174 __sys_bpf+0x18ff/0x58b0 kernel/bpf/syscall.c:5724 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5765 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf72d0579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f5ec25ac EFLAGS: 00000292 ORIG_RAX: 0000000000000165 RAX: ffffffffffffffda RBX: 000000000000001a RCX: 0000000020000300 RDX: 0000000000000038 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi