===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 6.1.84-syzkaller #0 Not tainted ----------------------------------------------------- syz-fuzzer/4008 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire: ffff888049c0c240 (&stab->lock){+...}-{2:2}, at: __sock_map_delete net/core/sock_map.c:416 [inline] ffff888049c0c240 (&stab->lock){+...}-{2:2}, at: sock_map_delete_elem+0x97/0x130 net/core/sock_map.c:448 and this task is already holding: ffff8880244aae58 (&sighand->siglock){-...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] ffff8880244aae58 (&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] 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 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] unlock_timer kernel/time/posix-timers.c:166 [inline] do_timer_settime+0x2d2/0x330 kernel/time/posix-timers.c:936 __do_sys_timer_settime kernel/time/posix-timers.c:956 [inline] __se_sys_timer_settime kernel/time/posix-timers.c:942 [inline] __x64_sys_timer_settime+0x1a2/0x250 kernel/time/posix-timers.c:942 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_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 nlmon_xmit+0xab/0xf0 drivers/net/nlmon.c:15 __netdev_start_xmit include/linux/netdevice.h:4853 [inline] netdev_start_xmit include/linux/netdevice.h:4867 [inline] xmit_one net/core/dev.c:3627 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643 __dev_queue_xmit+0x1bb1/0x3cf0 net/core/dev.c:4293 dev_queue_xmit include/linux/netdevice.h:3021 [inline] __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline] __netlink_deliver_tap+0x510/0x770 net/netlink/af_netlink.c:325 netlink_deliver_tap+0x19d/0x1b0 net/netlink/af_netlink.c:338 netlink_deliver_tap_kernel net/netlink/af_netlink.c:347 [inline] netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline] netlink_unicast+0x7aa/0x970 net/netlink/af_netlink.c:1352 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514 ___sys_sendmsg net/socket.c:2568 [inline] __sys_sendmsg+0x2a9/0x390 net/socket.c:2597 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/4008: #0: ffff8880244aae58 (&sighand->siglock){-...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #0: ffff8880244aae58 (&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] 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 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] unlock_timer kernel/time/posix-timers.c:166 [inline] do_timer_settime+0x2d2/0x330 kernel/time/posix-timers.c:936 __do_sys_timer_settime kernel/time/posix-timers.c:956 [inline] __se_sys_timer_settime kernel/time/posix-timers.c:942 [inline] __x64_sys_timer_settime+0x1a2/0x250 kernel/time/posix-timers.c:942 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_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_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 nlmon_xmit+0xab/0xf0 drivers/net/nlmon.c:15 __netdev_start_xmit include/linux/netdevice.h:4853 [inline] netdev_start_xmit include/linux/netdevice.h:4867 [inline] xmit_one net/core/dev.c:3627 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643 __dev_queue_xmit+0x1bb1/0x3cf0 net/core/dev.c:4293 dev_queue_xmit include/linux/netdevice.h:3021 [inline] __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline] __netlink_deliver_tap+0x510/0x770 net/netlink/af_netlink.c:325 netlink_deliver_tap+0x19d/0x1b0 net/netlink/af_netlink.c:338 netlink_deliver_tap_kernel net/netlink/af_netlink.c:347 [inline] netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline] netlink_unicast+0x7aa/0x970 net/netlink/af_netlink.c:1352 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514 ___sys_sendmsg net/socket.c:2568 [inline] __sys_sendmsg+0x2a9/0x390 net/socket.c:2597 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_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 nlmon_xmit+0xab/0xf0 drivers/net/nlmon.c:15 __netdev_start_xmit include/linux/netdevice.h:4853 [inline] netdev_start_xmit include/linux/netdevice.h:4867 [inline] xmit_one net/core/dev.c:3627 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643 __dev_queue_xmit+0x1bb1/0x3cf0 net/core/dev.c:4293 dev_queue_xmit include/linux/netdevice.h:3021 [inline] __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline] __netlink_deliver_tap+0x510/0x770 net/netlink/af_netlink.c:325 netlink_deliver_tap+0x19d/0x1b0 net/netlink/af_netlink.c:338 netlink_deliver_tap_kernel net/netlink/af_netlink.c:347 [inline] netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline] netlink_unicast+0x7aa/0x970 net/netlink/af_netlink.c:1352 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514 ___sys_sendmsg net/socket.c:2568 [inline] __sys_sendmsg+0x2a9/0x390 net/socket.c:2597 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 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 stack backtrace: CPU: 1 PID: 4008 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 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0033:0x747995 Code: 45 8d 1c 02 44 0f b6 63 01 45 01 e2 45 01 d3 44 0f b6 63 02 45 01 e2 45 01 d3 44 0f b6 63 03 43 8d 14 14 48 83 c7 fc 49 89 fa <49> f7 da 49 c1 fa 3f 41 83 e2 04 42 8d 04 1a 4c 01 d3 48 83 c1 fc RSP: 002b:000000c000504ce8 EFLAGS: 00000217 RAX: 00000000006f990a RBX: 000000c000b2d7cc RCX: 0000000000000834 RDX: 0000000000003499 RSI: 0000000000000000 RDI: 0000000000000830 RBP: 000000c000504d10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000830 R11: 00000000007036d5 R12: 0000000000000000 R13: 0000000000007f39 R14: 000000c0000061a0 R15: 0000000000000001