===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 6.8.0-syzkaller-05236-g443574b03387 #0 Not tainted ----------------------------------------------------- syz-executor.2/12796 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire: ffff88802c63ea00 (&stab->lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88802c63ea00 (&stab->lock){+...}-{2:2}, at: __sock_map_delete net/core/sock_map.c:414 [inline] ffff88802c63ea00 (&stab->lock){+...}-{2:2}, at: sock_map_delete_elem+0x97/0x140 net/core/sock_map.c:446 and this task is already holding: ffff8880289d0958 (&sighand->siglock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] ffff8880289d0958 (&sighand->siglock){-.-.}-{2:2}, at: get_signal+0x247/0x1850 kernel/signal.c:2699 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+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x274/0x310 kernel/signal.c:1453 do_bpf_send_signal+0x85/0x190 kernel/trace/bpf_trace.c:838 irq_work_single+0xe2/0x240 kernel/irq_work.c:221 irq_work_run_list kernel/irq_work.c:252 [inline] irq_work_run+0x18b/0x350 kernel/irq_work.c:261 __sysvec_irq_work+0xa8/0x3e0 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x9e/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] ref_tracker_dir_exit+0x3f8/0x550 lib/ref_tracker.c:178 free_netdev+0x2b7/0x4d0 net/core/dev.c:10970 netdev_run_todo+0xe5b/0x1000 net/core/dev.c:10586 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0x13a/0x1b0 drivers/net/tun.c:3498 __fput+0x429/0x8a0 fs/file_table.c:423 __do_sys_close fs/open.c:1557 [inline] __se_sys_close fs/open.c:1542 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1542 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 to a HARDIRQ-irq-unsafe lock: (&stab->lock){+...}-{2:2} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:490 sock_map_update_elem_sys+0x55f/0x910 net/core/sock_map.c:579 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5619 __do_sys_bpf kernel/bpf/syscall.c:5738 [inline] __se_sys_bpf kernel/bpf/syscall.c:5736 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 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-executor.2/12796: #0: ffff8880289d0958 (&sighand->siglock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #0: ffff8880289d0958 (&sighand->siglock){-.-.}-{2:2}, at: get_signal+0x247/0x1850 kernel/signal.c:2699 #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x14a/0x460 kernel/trace/bpf_trace.c:2421 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&sighand->siglock){-.-.}-{2:2} { IN-HARDIRQ-W at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x274/0x310 kernel/signal.c:1453 do_bpf_send_signal+0x85/0x190 kernel/trace/bpf_trace.c:838 irq_work_single+0xe2/0x240 kernel/irq_work.c:221 irq_work_run_list kernel/irq_work.c:252 [inline] irq_work_run+0x18b/0x350 kernel/irq_work.c:261 __sysvec_irq_work+0xa8/0x3e0 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x9e/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] ref_tracker_dir_exit+0x3f8/0x550 lib/ref_tracker.c:178 free_netdev+0x2b7/0x4d0 net/core/dev.c:10970 netdev_run_todo+0xe5b/0x1000 net/core/dev.c:10586 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0x13a/0x1b0 drivers/net/tun.c:3498 __fput+0x429/0x8a0 fs/file_table.c:423 __do_sys_close fs/open.c:1557 [inline] __se_sys_close fs/open.c:1542 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1542 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 IN-SOFTIRQ-W at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x274/0x310 kernel/signal.c:1453 bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881 ____bpf_send_signal kernel/trace/bpf_trace.c:886 [inline] bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:884 0xffffffffa00006bf bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:650 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x375/0x420 kernel/trace/bpf_trace.c:2420 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x291/0x380 mm/slub.c:4396 ref_tracker_free+0x4ef/0x7e0 lib/ref_tracker.c:272 netdev_tracker_free include/linux/netdevice.h:4084 [inline] netdev_put include/linux/netdevice.h:4101 [inline] fib_nh_common_release+0x52/0x430 net/ipv4/fib_semantics.c:215 fib_nh_release net/ipv4/fib_semantics.c:229 [inline] free_fib_info_rcu+0xdc/0x490 net/ipv4/fib_semantics.c:241 rcu_do_batch kernel/rcu/tree.c:2196 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471 __do_softirq+0x2bc/0x943 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 unlock_hrtimer_base kernel/time/hrtimer.c:1021 [inline] hrtimer_try_to_cancel+0x3b6/0x410 kernel/time/hrtimer.c:1343 hrtimer_cancel+0x16/0x50 kernel/time/hrtimer.c:1450 futex_wait+0x115/0x360 kernel/futex/waitwake.c:703 do_futex+0x33b/0x560 kernel/futex/syscalls.c:102 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 INITIAL USE at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] calculate_sigpending+0x4f/0x90 kernel/signal.c:188 ret_from_fork+0x24/0x80 arch/x86/kernel/process.c:143 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 } ... 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+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:490 sock_map_update_elem_sys+0x55f/0x910 net/core/sock_map.c:579 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5619 __do_sys_bpf kernel/bpf/syscall.c:5738 [inline] __se_sys_bpf kernel/bpf/syscall.c:5736 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 INITIAL USE at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:490 sock_map_update_elem_sys+0x55f/0x910 net/core/sock_map.c:579 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5619 __do_sys_bpf kernel/bpf/syscall.c:5738 [inline] __se_sys_bpf kernel/bpf/syscall.c:5736 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 } ... key at: [] sock_map_alloc.__key+0x0/0x20 ... acquired at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] __sock_map_delete net/core/sock_map.c:414 [inline] sock_map_delete_elem+0x97/0x140 net/core/sock_map.c:446 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 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_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421 __traceiter_signal_deliver+0x80/0xd0 include/trace/events/signal.h:96 trace_signal_deliver+0x178/0x1e0 include/trace/events/signal.h:96 get_signal+0x68d/0x1850 kernel/signal.c:2803 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x79/0x270 kernel/entry/common.c:225 exc_general_protection+0x410/0x5d0 arch/x86/kernel/traps.c:644 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 stack backtrace: CPU: 1 PID: 12796 Comm: syz-executor.2 Not tainted 6.8.0-syzkaller-05236-g443574b03387 #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+0x1e7/0x2e0 lib/dump_stack.c:106 print_bad_irq_dependency kernel/locking/lockdep.c:2626 [inline] check_irq_usage kernel/locking/lockdep.c:2865 [inline] check_prev_add kernel/locking/lockdep.c:3138 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x4dc7/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] __sock_map_delete net/core/sock_map.c:414 [inline] sock_map_delete_elem+0x97/0x140 net/core/sock_map.c:446 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 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_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421 __traceiter_signal_deliver+0x80/0xd0 include/trace/events/signal.h:96 trace_signal_deliver+0x178/0x1e0 include/trace/events/signal.h:96 get_signal+0x68d/0x1850 kernel/signal.c:2803 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x79/0x270 kernel/entry/common.c:225 exc_general_protection+0x410/0x5d0 arch/x86/kernel/traps.c:644 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 RIP: 0033:0x7fbde906fd39 Code: f8 77 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 89 f8 48 89 fa c5 f9 ef c0 25 ff 0f 00 00 3d e0 0f 00 00 0f 87 27 01 00 00 fd 74 0f c5 fd d7 c1 85 c0 74 5b f3 0f bc c0 e9 30 01 00 00 66 RSP: 002b:00007fbde9e2e858 EFLAGS: 00010283 RAX: 0000000000000999 RBX: 00007fbde9e2edc0 RCX: 00007fbde9175bc0 RDX: 9999999999999999 RSI: 00007fbde90c9062 RDI: 9999999999999999 RBP: 000000000000000b R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000000073 R13: 00007fbde9e2ef40 R14: 9999999999999999 R15: 0000000000000000