====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc6-syzkaller-00005-g557329bcecc2 #0 Not tainted ------------------------------------------------------ syz.2.2024/10424 is trying to acquire lock: ffff888040000220 (&pgdat->kswapd_wait){....}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:105 [inline] ffff888040000220 (&pgdat->kswapd_wait){....}-{2:2}, at: __wake_up+0x1c/0x60 kernel/sched/wait.c:127 but task is already holding lock: ffff888021da1a00 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc7/0xdb0 kernel/bpf/lpm_trie.c:333 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+0xb0/0x820 kernel/bpf/lpm_trie.c:462 0xffffffffa00022e3 bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2316 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2357 trace_tlb_flush+0xf3/0x170 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x395/0xb10 arch/x86/mm/tlb.c:637 context_switch kernel/sched/core.c:5312 [inline] __schedule+0xc6c/0x5740 kernel/sched/core.c:6690 schedule_idle+0x5c/0x90 kernel/sched/core.c:6808 do_idle+0x287/0x3f0 kernel/sched/idle.c:354 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:424 rest_init+0x16b/0x2b0 init/main.c:747 start_kernel+0x3e4/0x4d0 init/main.c:1105 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 -> #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:598 raw_spin_rq_lock kernel/sched/sched.h:1505 [inline] task_rq_lock+0xcf/0x3b0 kernel/sched/core.c:700 cgroup_move_task+0x82/0x250 kernel/sched/psi.c:1161 css_set_move_task+0x288/0x5f0 kernel/cgroup/cgroup.c:898 cgroup_post_fork+0x1c6/0x910 kernel/cgroup/cgroup.c:6692 copy_process+0x5759/0x6ee0 kernel/fork.c:2600 kernel_clone+0xfd/0x960 kernel/fork.c:2786 user_mode_thread+0xb4/0xf0 kernel/fork.c:2864 rest_init+0x23/0x2b0 init/main.c:712 start_kernel+0x3e4/0x4d0 init/main.c:1105 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:551 [inline] try_to_wake_up+0xa1/0x14f0 kernel/sched/core.c:4165 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:7292 rmqueue mm/page_alloc.c:3070 [inline] get_page_from_freelist+0x5ae/0x2d10 mm/page_alloc.c:3454 __alloc_pages_noprof+0x223/0x25a0 mm/page_alloc.c:4733 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] ___kmalloc_large_node+0x84/0x1b0 mm/slub.c:4209 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:4236 __do_kmalloc_node mm/slub.c:4252 [inline] __kmalloc_node_noprof.cold+0x5/0x5f mm/slub.c:4270 __kvmalloc_node_noprof+0x6f/0x1a0 mm/util.c:658 kvmalloc_array_node_noprof include/linux/slab.h:1040 [inline] nf_ct_alloc_hashtable+0x93/0x150 net/netfilter/nf_conntrack_core.c:2526 nf_nat_init+0x75/0x1f0 net/netfilter/nf_nat_core.c:1339 do_one_initcall+0x128/0x630 init/main.c:1269 do_initcall_level init/main.c:1331 [inline] do_initcalls init/main.c:1347 [inline] do_basic_setup init/main.c:1366 [inline] kernel_init_freeable+0x58f/0x8b0 init/main.c:1580 kernel_init+0x1c/0x2b0 init/main.c:1469 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (&pgdat->kswapd_wait){....}-{2:2}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __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:7292 rmqueue mm/page_alloc.c:3070 [inline] get_page_from_freelist+0x5ae/0x2d10 mm/page_alloc.c:3454 __alloc_pages_noprof+0x223/0x25a0 mm/page_alloc.c:4733 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] ___kmalloc_large_node+0x84/0x1b0 mm/slub.c:4209 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:4236 __do_kmalloc_node mm/slub.c:4252 [inline] __kmalloc_node_noprof.cold+0x5/0x5f mm/slub.c:4270 kmalloc_node_noprof include/linux/slab.h:905 [inline] bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline] trie_update_elem+0x1ef/0xdb0 kernel/bpf/lpm_trie.c:342 bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203 generic_map_update_batch+0x454/0x5f0 kernel/bpf/syscall.c:1849 bpf_map_do_batch+0x576/0x640 kernel/bpf/syscall.c:5162 __sys_bpf+0x1c9f/0x5780 kernel/bpf/syscall.c:5717 __do_sys_bpf kernel/bpf/syscall.c:5760 [inline] __se_sys_bpf kernel/bpf/syscall.c:5758 [inline] __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5758 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 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.2.2024/10424: #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x24b/0x6c0 kernel/bpf/syscall.c:202 #1: ffff888021da1a00 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc7/0xdb0 kernel/bpf/lpm_trie.c:333 stack backtrace: CPU: 0 UID: 0 PID: 10424 Comm: syz.2.2024 Not tainted 6.12.0-rc6-syzkaller-00005-g557329bcecc2 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __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:7292 rmqueue mm/page_alloc.c:3070 [inline] get_page_from_freelist+0x5ae/0x2d10 mm/page_alloc.c:3454 __alloc_pages_noprof+0x223/0x25a0 mm/page_alloc.c:4733 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] ___kmalloc_large_node+0x84/0x1b0 mm/slub.c:4209 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:4236 __do_kmalloc_node mm/slub.c:4252 [inline] __kmalloc_node_noprof.cold+0x5/0x5f mm/slub.c:4270 kmalloc_node_noprof include/linux/slab.h:905 [inline] bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline] trie_update_elem+0x1ef/0xdb0 kernel/bpf/lpm_trie.c:342 bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203 generic_map_update_batch+0x454/0x5f0 kernel/bpf/syscall.c:1849 bpf_map_do_batch+0x576/0x640 kernel/bpf/syscall.c:5162 __sys_bpf+0x1c9f/0x5780 kernel/bpf/syscall.c:5717 __do_sys_bpf kernel/bpf/syscall.c:5760 [inline] __se_sys_bpf kernel/bpf/syscall.c:5758 [inline] __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5758 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 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: 0023:0xf7fc6579 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:00000000f574655c EFLAGS: 00000296 ORIG_RAX: 0000000000000165 RAX: ffffffffffffffda RBX: 000000000000001a RCX: 0000000020000500 RDX: 0000000000000038 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 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