====================================================== WARNING: possible circular locking dependency detected 6.1.122-syzkaller #0 Tainted: G W ------------------------------------------------------ cmp/3960 is trying to acquire lock: ffff8880b9828118 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] ffff8880b9828118 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] ffff8880b9828118 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402 but task is already holding lock: ffff8880b9828358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&base->lock){-.-.}-{2:2}: 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_timer_base+0x120/0x260 kernel/time/timer.c:999 __mod_timer+0x1cb/0xee0 kernel/time/timer.c:1072 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704 queue_delayed_work include/linux/workqueue.h:527 [inline] schedule_delayed_monitor_work kernel/rcu/tree.c:3172 [inline] kvfree_call_rcu+0x520/0x8c0 kernel/rcu/tree.c:3428 rtnl_register_internal+0x489/0x580 net/core/rtnetlink.c:260 rtnl_register+0x32/0x70 net/core/rtnetlink.c:310 ip_rt_init+0x335/0x3c7 net/ipv4/route.c:3763 ip_init+0xa/0x14 net/ipv4/ip_output.c:1770 inet_init+0x2ae/0x3c0 net/ipv4/af_inet.c:2033 do_one_initcall+0x265/0x8f0 init/main.c:1298 do_initcall_level+0x157/0x207 init/main.c:1371 do_initcalls+0x49/0x86 init/main.c:1387 kernel_init_freeable+0x45c/0x60f init/main.c:1626 kernel_init+0x19/0x290 init/main.c:1514 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 (krc.lock){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 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 include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402 trie_delete_elem+0x53a/0x690 kernel/bpf/lpm_trie.c:545 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:992 [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:2284 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2324 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x440/0x600 kernel/time/timer.c:609 __mod_timer+0x92b/0xee0 mrp_join_timer_arm net/802/mrp.c:596 [inline] mrp_join_timer+0x144/0x180 net/802/mrp.c:611 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571 __do_softirq kernel/softirq.c:605 [inline] invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 lock_is_held_type+0x137/0x180 mt_slot lib/maple_tree.c:814 [inline] mas_slot lib/maple_tree.c:847 [inline] mas_get_slot lib/maple_tree.c:6685 [inline] mas_validate_gaps lib/maple_tree.c:6983 [inline] mt_validate+0x37c7/0x5ad0 lib/maple_tree.c:7251 validate_mm_mt+0x165/0x670 mm/mmap.c:294 __split_vma+0x32/0x4c0 mm/mmap.c:2343 mprotect_fixup+0x753/0x840 mm/mprotect.c:623 do_mprotect_pkey+0x8b6/0xbe0 mm/mprotect.c:792 __do_sys_mprotect mm/mprotect.c:819 [inline] __se_sys_mprotect mm/mprotect.c:816 [inline] __x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:816 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&base->lock); lock(krc.lock); lock(&base->lock); lock(krc.lock); *** DEADLOCK *** 6 locks held by cmp/3960: #0: ffff88807ac0f1d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff88807ac0f1d8 (&mm->mmap_lock){++++}-{3:3}, at: do_mprotect_pkey+0x2d0/0xbe0 mm/mprotect.c:702 #1: ffffffff8d12b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8d12b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8d12b0c0 (rcu_read_lock){....}-{1:2}, at: mt_validate+0x1be/0x5ad0 lib/maple_tree.c:7229 #2: ffffc90000007bc0 ((&app->join_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc2/0x6b0 kernel/time/timer.c:1501 #3: ffff8880736304c8 (&app->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff8880736304c8 (&app->lock){+.-.}-{2:2}, at: mrp_join_timer+0xca/0x180 net/802/mrp.c:609 #4: ffff8880b9828358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 #5: ffffffff8d12b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #5: ffffffff8d12b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #5: ffffffff8d12b0c0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline] #5: ffffffff8d12b0c0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x146/0x440 kernel/trace/bpf_trace.c:2324 stack backtrace: CPU: 0 PID: 3960 Comm: cmp Tainted: G W 6.1.122-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 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 include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402 trie_delete_elem+0x53a/0x690 kernel/bpf/lpm_trie.c:545 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:992 [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:2284 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2324 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x440/0x600 kernel/time/timer.c:609 __mod_timer+0x92b/0xee0 mrp_join_timer_arm net/802/mrp.c:596 [inline] mrp_join_timer+0x144/0x180 net/802/mrp.c:611 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571 __do_softirq kernel/softirq.c:605 [inline] invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_is_held_type+0x137/0x180 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc900048877f8 EFLAGS: 00000206 RAX: 6ff50d5b79afee00 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff8aec14c0 RDI: ffffffff8b3d7ec0 RBP: 0000000000000001 R08: ffffffff8a85d663 R09: ffffffff8a85d37b R10: 0000000000000003 R11: ffff888026d5d940 R12: 0000000000000246 R13: ffff888026d5d940 R14: 00000000ffffffff R15: ffff88807ac0f1d8 mt_slot lib/maple_tree.c:814 [inline] mas_slot lib/maple_tree.c:847 [inline] mas_get_slot lib/maple_tree.c:6685 [inline] mas_validate_gaps lib/maple_tree.c:6983 [inline] mt_validate+0x37c7/0x5ad0 lib/maple_tree.c:7251 validate_mm_mt+0x165/0x670 mm/mmap.c:294 __split_vma+0x32/0x4c0 mm/mmap.c:2343 mprotect_fixup+0x753/0x840 mm/mprotect.c:623 do_mprotect_pkey+0x8b6/0xbe0 mm/mprotect.c:792 __do_sys_mprotect mm/mprotect.c:819 [inline] __se_sys_mprotect mm/mprotect.c:816 [inline] __x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:816 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f042bd62bb7 Code: 00 00 00 b8 0b 00 00 00 0f 05 48 3d 01 f0 ff ff 73 01 c3 48 8d 0d b9 46 01 00 f7 d8 89 01 48 83 c8 ff c3 b8 0a 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8d 0d 99 46 01 00 f7 d8 89 01 48 83 RSP: 002b:00007ffdc2178288 EFLAGS: 00000206 ORIG_RAX: 000000000000000a RAX: ffffffffffffffda RBX: 00007f042bd46570 RCX: 00007f042bd62bb7 RDX: 0000000000000001 RSI: 0000000000001000 RDI: 00007f042ba98000 RBP: 00007ffdc21783a0 R08: 00007ffdc2178218 R09: 00007f042bd455c0 R10: 00007f042ba45928 R11: 0000000000000206 R12: 00007f042bd46570 R13: 00007f042bd6aeda R14: 00007f042ba98fb0 R15: 00007f042ba98e58 ---------------- Code disassembly (best guess): 0: 75 40 jne 0x42 2: 48 c7 04 24 00 00 00 movq $0x0,(%rsp) 9: 00 a: 9c pushf b: 8f 04 24 pop (%rsp) e: f7 04 24 00 02 00 00 testl $0x200,(%rsp) 15: 75 46 jne 0x5d 17: 41 f7 c4 00 02 00 00 test $0x200,%r12d 1e: 74 01 je 0x21 20: fb sti 21: 65 48 8b 04 25 28 00 mov %gs:0x28,%rax 28: 00 00 * 2a: 48 3b 44 24 08 cmp 0x8(%rsp),%rax <-- trapping instruction 2f: 75 3c jne 0x6d 31: 89 e8 mov %ebp,%eax 33: 48 83 c4 10 add $0x10,%rsp 37: 5b pop %rbx 38: 41 5c pop %r12 3a: 41 5d pop %r13 3c: 41 5e pop %r14 3e: 41 5f pop %r15