===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 6.1.84-syzkaller #0 Not tainted ----------------------------------------------------- syz-fuzzer/3562 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire: ffff88801f1cea40 (&stab->lock){+...}-{2:2}, at: __sock_map_delete net/core/sock_map.c:416 [inline] ffff88801f1cea40 (&stab->lock){+...}-{2:2}, at: sock_map_delete_elem+0x97/0x130 net/core/sock_map.c:448 and this task is already holding: ffff888023234a18 (&sighand->siglock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] ffff888023234a18 (&sighand->siglock){-.-.}-{2:2}, at: get_signal+0x242/0x17d0 kernel/signal.c:2655 which would create a new lock dependency: (&sighand->siglock){-.-.}-{2:2} -> (&stab->lock){+...}-{2:2} but this new dependency connects a HARDIRQ-irq-safe lock: (&sighand->siglock){-.-.}-{2:2} ... which became HARDIRQ-irq-safe at: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x145/0x2d0 kernel/signal.c:1410 lock_task_sighand include/linux/sched/signal.h:745 [inline] do_send_sig_info kernel/signal.c:1299 [inline] group_send_sig_info+0x26c/0x300 kernel/signal.c:1448 do_bpf_send_signal+0x81/0x150 kernel/trace/bpf_trace.c:839 irq_work_single+0xd5/0x230 kernel/irq_work.c:211 irq_work_run_list kernel/irq_work.c:242 [inline] irq_work_run+0x187/0x350 kernel/irq_work.c:251 __sysvec_irq_work+0xbb/0x360 arch/x86/kernel/irq_work.c:22 sysvec_irq_work+0x89/0xb0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:679 put_flush_tlb_info arch/x86/mm/tlb.c:977 [inline] flush_tlb_mm_range+0x41f/0x590 arch/x86/mm/tlb.c:1018 pmdp_huge_clear_flush+0x233/0x290 mm/pgtable-generic.c:142 __split_huge_zero_page_pmd mm/huge_memory.c:2030 [inline] __split_huge_pmd_locked mm/huge_memory.c:2108 [inline] __split_huge_pmd+0x9ad/0x43b0 mm/huge_memory.c:2308 split_huge_pmd_address mm/huge_memory.c:2337 [inline] split_huge_pmd_if_needed mm/huge_memory.c:2349 [inline] vma_adjust_trans_huge+0x246/0x3c0 mm/huge_memory.c:2361 __vma_adjust+0x923/0x1f40 mm/mmap.c:731 __split_vma+0x36e/0x530 do_mas_align_munmap+0x41c/0x15f0 mm/mmap.c:2470 do_mas_munmap+0x246/0x2b0 mm/mmap.c:2640 do_munmap+0x181/0x1d0 mm/mmap.c:2654 mremap_to mm/mremap.c:820 [inline] __do_sys_mremap mm/mremap.c:972 [inline] __se_sys_mremap+0x104d/0x1b20 mm/mremap.c:889 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd to a HARDIRQ-irq-unsafe lock: (&stab->lock){+...}-{2:2} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:492 sock_map_update_elem_sys+0x55b/0x910 net/core/sock_map.c:581 map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1448 __sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:4993 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline] __se_sys_bpf kernel/bpf/syscall.c:5107 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&stab->lock); local_irq_disable(); lock(&sighand->siglock); lock(&stab->lock); lock(&sighand->siglock); *** DEADLOCK *** 2 locks held by syz-fuzzer/3562: #0: ffff888023234a18 (&sighand->siglock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #0: ffff888023234a18 (&sighand->siglock){-.-.}-{2:2}, at: get_signal+0x242/0x17d0 kernel/signal.c:2655 #1: ffffffff8d12a980 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8d12a980 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8d12a980 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline] #1: ffffffff8d12a980 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x146/0x440 kernel/trace/bpf_trace.c:2313 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&sighand->siglock){-.-.}-{2:2} { IN-HARDIRQ-W at: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x145/0x2d0 kernel/signal.c:1410 lock_task_sighand include/linux/sched/signal.h:745 [inline] do_send_sig_info kernel/signal.c:1299 [inline] group_send_sig_info+0x26c/0x300 kernel/signal.c:1448 do_bpf_send_signal+0x81/0x150 kernel/trace/bpf_trace.c:839 irq_work_single+0xd5/0x230 kernel/irq_work.c:211 irq_work_run_list kernel/irq_work.c:242 [inline] irq_work_run+0x187/0x350 kernel/irq_work.c:251 __sysvec_irq_work+0xbb/0x360 arch/x86/kernel/irq_work.c:22 sysvec_irq_work+0x89/0xb0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:679 put_flush_tlb_info arch/x86/mm/tlb.c:977 [inline] flush_tlb_mm_range+0x41f/0x590 arch/x86/mm/tlb.c:1018 pmdp_huge_clear_flush+0x233/0x290 mm/pgtable-generic.c:142 __split_huge_zero_page_pmd mm/huge_memory.c:2030 [inline] __split_huge_pmd_locked mm/huge_memory.c:2108 [inline] __split_huge_pmd+0x9ad/0x43b0 mm/huge_memory.c:2308 split_huge_pmd_address mm/huge_memory.c:2337 [inline] split_huge_pmd_if_needed mm/huge_memory.c:2349 [inline] vma_adjust_trans_huge+0x246/0x3c0 mm/huge_memory.c:2361 __vma_adjust+0x923/0x1f40 mm/mmap.c:731 __split_vma+0x36e/0x530 do_mas_align_munmap+0x41c/0x15f0 mm/mmap.c:2470 do_mas_munmap+0x246/0x2b0 mm/mmap.c:2640 do_munmap+0x181/0x1d0 mm/mmap.c:2654 mremap_to mm/mremap.c:820 [inline] __do_sys_mremap mm/mremap.c:972 [inline] __se_sys_mremap+0x104d/0x1b20 mm/mremap.c:889 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd IN-SOFTIRQ-W at: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x145/0x2d0 kernel/signal.c:1410 lock_task_sighand include/linux/sched/signal.h:745 [inline] send_sigqueue+0x1de/0x720 kernel/signal.c:1978 posix_timer_event kernel/time/posix-timers.c:354 [inline] posix_timer_fn+0x186/0x390 kernel/time/posix-timers.c:380 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 lock_is_held_type+0x137/0x180 __in6_dev_get include/net/addrconf.h:323 [inline] ip6_ignore_linkdown include/net/addrconf.h:414 [inline] find_match+0xe3/0xbe0 net/ipv6/route.c:744 __find_rr_leaf+0x271/0x8e0 net/ipv6/route.c:832 find_rr_leaf net/ipv6/route.c:853 [inline] rt6_select net/ipv6/route.c:897 [inline] fib6_table_lookup+0x40f/0xbb0 net/ipv6/route.c:2185 ip6_pol_route+0x207/0x14e0 net/ipv6/route.c:2221 pol_lookup_func include/net/ip6_fib.h:579 [inline] fib6_rule_lookup+0x265/0x620 net/ipv6/fib6_rules.c:116 ip6_route_input_lookup net/ipv6/route.c:2290 [inline] ip6_route_input+0x830/0xd90 net/ipv6/route.c:2586 ip6_rcv_finish+0x140/0x230 net/ipv6/ip6_input.c:77 NF_HOOK+0x39d/0x450 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5528 [inline] __netif_receive_skb+0x1c6/0x530 net/core/dev.c:5642 process_backlog+0x381/0x760 net/core/dev.c:5970 __napi_poll+0xc7/0x470 net/core/dev.c:6537 napi_poll net/core/dev.c:6604 [inline] net_rx_action+0x70f/0xeb0 net/core/dev.c:6718 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 run_ksoftirqd+0xc1/0x120 kernel/softirq.c:934 smpboot_thread_fn+0x52c/0xa30 kernel/smpboot.c:164 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 INITIAL USE at: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] calculate_sigpending+0x4a/0x80 kernel/signal.c:195 ret_from_fork+0x8/0x30 arch/x86/entry/entry_64.S:292 } ... key at: [] sighand_ctor.__key+0x0/0x20 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (&stab->lock){+...}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:492 sock_map_update_elem_sys+0x55b/0x910 net/core/sock_map.c:581 map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1448 __sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:4993 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline] __se_sys_bpf kernel/bpf/syscall.c:5107 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd INITIAL USE at: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:492 sock_map_update_elem_sys+0x55b/0x910 net/core/sock_map.c:581 map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1448 __sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:4993 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline] __se_sys_bpf kernel/bpf/syscall.c:5107 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd } ... key at: [] sock_map_alloc.__key+0x0/0x20 ... acquired at: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 __sock_map_delete net/core/sock_map.c:416 [inline] sock_map_delete_elem+0x97/0x130 net/core/sock_map.c:448 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2313 __bpf_trace_kmem_cache_free+0x99/0xc0 include/trace/events/kmem.h:114 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x418/0x510 mm/slub.c:3682 __sigqueue_free kernel/signal.c:458 [inline] collect_signal kernel/signal.c:601 [inline] __dequeue_signal+0x4ac/0x5c0 kernel/signal.c:623 dequeue_signal+0xd4/0x590 kernel/signal.c:643 get_signal+0x5f2/0x17d0 kernel/signal.c:2742 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x63/0xcd stack backtrace: CPU: 1 PID: 3562 Comm: syz-fuzzer Not tainted 6.1.84-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_bad_irq_dependency kernel/locking/lockdep.c:2604 [inline] check_irq_usage kernel/locking/lockdep.c:2843 [inline] check_prev_add kernel/locking/lockdep.c:3094 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x4d16/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 __sock_map_delete net/core/sock_map.c:416 [inline] sock_map_delete_elem+0x97/0x130 net/core/sock_map.c:448 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2313 __bpf_trace_kmem_cache_free+0x99/0xc0 include/trace/events/kmem.h:114 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x418/0x510 mm/slub.c:3682 __sigqueue_free kernel/signal.c:458 [inline] collect_signal kernel/signal.c:601 [inline] __dequeue_signal+0x4ac/0x5c0 kernel/signal.c:623 dequeue_signal+0xd4/0x590 kernel/signal.c:643 get_signal+0x5f2/0x17d0 kernel/signal.c:2742 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x472e43 Code: 24 20 c3 cc cc cc cc 48 8b 7c 24 08 8b 74 24 10 8b 54 24 14 4c 8b 54 24 18 4c 8b 44 24 20 44 8b 4c 24 28 b8 ca 00 00 00 0f 05 <89> 44 24 30 c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc RSP: 002b:000000c000bdfe90 EFLAGS: 00000206 ORIG_RAX: 00000000000000ca RAX: ffffffffffffff92 RBX: 0000000000000000 RCX: 0000000000472e43 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000024d0d98 RBP: 000000c000bdfed8 R08: 0000000000000000 R09: 0000000000000000 R10: 000000c000bdfec8 R11: 0000000000000206 R12: 000000c000bdfec8 R13: 0000000000000000 R14: 000000c0001e6000 R15: 000000000000077d