====================================================== WARNING: possible circular locking dependency detected 6.1.119-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor/4280 is trying to acquire lock: ffff8880b8e28118 (krc.lock){-.-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] ffff8880b8e28118 (krc.lock){-.-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] ffff8880b8e28118 (krc.lock){-.-.}-{2:2}, at: kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402 but task is already holding lock: ffff8880b8e28358 (&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:1767 inet_init+0x2ae/0x3c0 net/ipv4/af_inet.c:2035 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:532 bpf_prog_ae0c3e605f35524c+0x3d/0x41 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:2271 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2311 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x440/0x600 kernel/time/timer.c:609 internal_add_timer kernel/time/timer.c:634 [inline] add_timer_on+0x3e4/0x580 kernel/time/timer.c:1252 handle_irq_event_percpu kernel/irq/handle.c:195 [inline] handle_irq_event+0xa9/0x1e0 kernel/irq/handle.c:210 handle_fasteoi_irq+0x3de/0x940 kernel/irq/chip.c:714 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq arch/x86/kernel/irq.c:231 [inline] __common_interrupt+0xd7/0x1f0 arch/x86/kernel/irq.c:250 common_interrupt+0xae/0xd0 arch/x86/kernel/irq.c:240 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:682 lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666 fs_reclaim_acquire+0xaa/0x120 mm/page_alloc.c:4721 might_alloc include/linux/sched/mm.h:271 [inline] prepare_alloc_pages+0x147/0x5b0 mm/page_alloc.c:5360 __alloc_pages+0x16a/0x770 mm/page_alloc.c:5579 __pte_alloc_one include/asm-generic/pgalloc.h:63 [inline] pte_alloc_one+0x86/0x360 arch/x86/mm/pgtable.c:33 __pte_alloc+0x75/0x220 mm/memory.c:468 copy_pte_range mm/memory.c:1042 [inline] copy_pmd_range mm/memory.c:1177 [inline] copy_pud_range mm/memory.c:1214 [inline] copy_p4d_range mm/memory.c:1238 [inline] copy_page_range+0x3e3e/0x4660 mm/memory.c:1336 dup_mmap kernel/fork.c:697 [inline] dup_mm kernel/fork.c:1541 [inline] copy_mm+0xf42/0x1990 kernel/fork.c:1590 copy_process+0x19d5/0x4060 kernel/fork.c:2266 kernel_clone+0x222/0x920 kernel/fork.c:2681 __do_sys_clone kernel/fork.c:2822 [inline] __se_sys_clone kernel/fork.c:2806 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2806 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 *** 7 locks held by syz-executor/4280: #0: ffffffff8d3c5910 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline] #0: ffffffff8d3c5910 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline] #0: ffffffff8d3c5910 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x3cb/0x1990 kernel/fork.c:1590 #1: ffff88801fe55b58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff88801fe55b58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline] #1: ffff88801fe55b58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline] #1: ffff88801fe55b58 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x3e5/0x1990 kernel/fork.c:1590 #2: ffff8880754144d8 (&mm->mmap_lock/1){+.+.}-{3:3}, at: mmap_write_lock_nested include/linux/mmap_lock.h:78 [inline] #2: ffff8880754144d8 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mmap kernel/fork.c:603 [inline] #2: ffff8880754144d8 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline] #2: ffff8880754144d8 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_mm+0x4ca/0x1990 kernel/fork.c:1590 #3: ffffffff8d4054a0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:271 [inline] #3: ffffffff8d4054a0 (fs_reclaim){+.+.}-{0:0}, at: prepare_alloc_pages+0x147/0x5b0 mm/page_alloc.c:5360 #4: ffffffff8d417660 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: fs_reclaim_acquire+0x8e/0x120 mm/page_alloc.c:4721 #5: ffff8880b8e28358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 #6: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #6: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #6: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2270 [inline] #6: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x146/0x440 kernel/trace/bpf_trace.c:2311 stack backtrace: CPU: 0 PID: 4280 Comm: syz-executor Not tainted 6.1.119-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:532 bpf_prog_ae0c3e605f35524c+0x3d/0x41 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:2271 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2311 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x440/0x600 kernel/time/timer.c:609 internal_add_timer kernel/time/timer.c:634 [inline] add_timer_on+0x3e4/0x580 kernel/time/timer.c:1252 handle_irq_event_percpu kernel/irq/handle.c:195 [inline] handle_irq_event+0xa9/0x1e0 kernel/irq/handle.c:210 handle_fasteoi_irq+0x3de/0x940 kernel/irq/chip.c:714 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq arch/x86/kernel/irq.c:231 [inline] __common_interrupt+0xd7/0x1f0 arch/x86/kernel/irq.c:250 common_interrupt+0xae/0xd0 arch/x86/kernel/irq.c:240 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:682 RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666 Code: 2b 00 74 08 4c 89 f7 e8 af 81 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90003e87000 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920007d0e0c RCX: ffffffff816b5e82 RDX: dffffc0000000000 RSI: ffffffff8b0c1340 RDI: ffffffff8b5e6200 RBP: ffffc90003e87158 R08: dffffc0000000000 R09: fffffbfff224984f R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920007d0e08 R13: dffffc0000000000 R14: ffffc90003e87060 R15: 0000000000000246 fs_reclaim_acquire+0xaa/0x120 mm/page_alloc.c:4721 might_alloc include/linux/sched/mm.h:271 [inline] prepare_alloc_pages+0x147/0x5b0 mm/page_alloc.c:5360 __alloc_pages+0x16a/0x770 mm/page_alloc.c:5579 __pte_alloc_one include/asm-generic/pgalloc.h:63 [inline] pte_alloc_one+0x86/0x360 arch/x86/mm/pgtable.c:33 __pte_alloc+0x75/0x220 mm/memory.c:468 copy_pte_range mm/memory.c:1042 [inline] copy_pmd_range mm/memory.c:1177 [inline] copy_pud_range mm/memory.c:1214 [inline] copy_p4d_range mm/memory.c:1238 [inline] copy_page_range+0x3e3e/0x4660 mm/memory.c:1336 dup_mmap kernel/fork.c:697 [inline] dup_mm kernel/fork.c:1541 [inline] copy_mm+0xf42/0x1990 kernel/fork.c:1590 copy_process+0x19d5/0x4060 kernel/fork.c:2266 kernel_clone+0x222/0x920 kernel/fork.c:2681 __do_sys_clone kernel/fork.c:2822 [inline] __se_sys_clone kernel/fork.c:2806 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2806 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: 0033:0x7f6102f77053 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007fff9a635838 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6102f77053 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000555580b387d0 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000007f279 R14: 000000000007ef21 R15: 00007fff9a6359c0 ---------------- Code disassembly (best guess): 0: 2b 00 sub (%rax),%eax 2: 74 08 je 0xc 4: 4c 89 f7 mov %r14,%rdi 7: e8 af 81 77 00 call 0x7781bb c: f6 44 24 61 02 testb $0x2,0x61(%rsp) 11: 0f 85 84 01 00 00 jne 0x19b 17: 41 f7 c7 00 02 00 00 test $0x200,%r15d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 40 0e 36 movq $0x45e0360e,0x40(%rsp) 28: e0 45 * 2a: 4b c7 44 25 00 00 00 movq $0x0,0x0(%r13,%r12,1) <-- trapping instruction 31: 00 00 33: 43 c7 44 25 09 00 00 movl $0x0,0x9(%r13,%r12,1) 3a: 00 00 3c: 43 rex.XB 3d: c7 .byte 0xc7 3e: 44 rex.R 3f: 25 .byte 0x25