====================================================== WARNING: possible circular locking dependency detected 6.1.142-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor/7597 is trying to acquire lock: ffff8880b8e281d8 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] ffff8880b8e281d8 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] ffff8880b8e281d8 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3402 but task is already holding lock: ffff8880b8e28418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 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}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 lock_timer_base+0x123/0x270 kernel/time/timer.c:999 __mod_timer+0x117/0xd20 kernel/time/timer.c:1072 queue_delayed_work_on+0x126/0x1e0 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+0x4cb/0x870 kernel/rcu/tree.c:3428 rtnl_register_internal+0x489/0x590 net/core/rtnetlink.c:260 rtnl_register+0x2e/0x70 net/core/rtnetlink.c:310 ip_rt_init+0x323/0x3b5 net/ipv4/route.c:3793 ip_init+0xa/0x14 net/ipv4/ip_output.c:1771 inet_init+0x2bd/0x3cf net/ipv4/af_inet.c:2033 do_one_initcall+0x214/0x7a0 init/main.c:1298 do_initcall_level+0x137/0x1e4 init/main.c:1371 do_initcalls+0x4b/0x8a init/main.c:1387 kernel_init_freeable+0x3fa/0x5ac init/main.c:1626 kernel_init+0x19/0x1b0 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 kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 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+0x184/0x870 kernel/rcu/tree.c:3402 trie_delete_elem+0x52d/0x690 kernel/bpf/lpm_trie.c:545 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:1001 [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:2285 [inline] bpf_trace_run3+0x1e3/0x400 kernel/trace/bpf_trace.c:2325 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x411/0x5c0 kernel/time/timer.c:609 __mod_timer+0x88e/0xd20 kernel/time/timer.c:1113 sk_reset_timer+0x1f/0xb0 net/core/sock.c:3374 tcp_event_new_data_sent+0x20e/0x370 net/ipv4/tcp_output.c:81 tcp_write_xmit+0x1780/0x62b0 net/ipv4/tcp_output.c:2716 __tcp_push_pending_frames+0x93/0x340 net/ipv4/tcp_output.c:2894 tcp_push_pending_frames include/net/tcp.h:1986 [inline] tcp_data_snd_check net/ipv4/tcp_input.c:5599 [inline] tcp_rcv_established+0xf62/0x1d30 net/ipv4/tcp_input.c:6023 tcp_v4_do_rcv+0x48d/0xb00 net/ipv4/tcp_ipv4.c:1683 tcp_v4_rcv+0x2789/0x2e30 net/ipv4/tcp_ipv4.c:2114 ip_protocol_deliver_rcu+0x3ad/0x780 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2c7/0x510 net/ipv4/ip_input.c:233 NF_HOOK+0x2ff/0x390 include/linux/netfilter.h:302 dst_input include/net/dst.h:463 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0xa30/0xd10 net/ipv4/ip_input.c:639 ip_list_rcv+0x3df/0x430 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5612 [inline] __netif_receive_skb_list_core+0x574/0x740 net/core/dev.c:5660 __netif_receive_skb_list net/core/dev.c:5712 [inline] netif_receive_skb_list_internal+0x90f/0xc50 net/core/dev.c:5803 gro_normal_list include/net/gro.h:433 [inline] napi_complete_done+0x37d/0x830 net/core/dev.c:6144 virtqueue_napi_complete drivers/net/virtio_net.c:403 [inline] virtnet_poll+0x991/0x1150 drivers/net/virtio_net.c:1687 __napi_poll+0xc0/0x460 net/core/dev.c:6578 napi_poll net/core/dev.c:6645 [inline] net_rx_action+0x5b1/0xad0 net/core/dev.c:6759 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:682 lock_release+0x593/0x910 kernel/locking/lockdep.c:5686 rcu_lock_release include/linux/rcupdate.h:355 [inline] rcu_read_unlock_sched include/linux/rcupdate.h:904 [inline] pfn_valid+0x3c5/0x420 include/linux/mmzone.h:1867 page_table_check_set+0x25/0x6d0 mm/page_table_check.c:108 page_table_check_pte_set include/linux/page_table_check.h:83 [inline] set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline] do_set_pte+0x452/0x460 mm/memory.c:4426 filemap_map_pages+0xcab/0x10d0 mm/filemap.c:3481 do_fault_around mm/memory.c:4600 [inline] do_read_fault mm/memory.c:4626 [inline] do_fault mm/memory.c:4760 [inline] handle_pte_fault mm/memory.c:5031 [inline] __handle_mm_fault mm/memory.c:5173 [inline] handle_mm_fault+0x2889/0x3e70 mm/memory.c:5294 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 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 *** 8 locks held by syz-executor/7597: #0: ffff88807ebf6a58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807ebf6a58 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5322 [inline] #0: ffff88807ebf6a58 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5384 #1: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: filemap_map_pages+0x18b/0x10d0 mm/filemap.c:3444 #2: ffff8880792aae58 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff8880792aae58 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: filemap_map_pages+0x8c1/0x10d0 mm/filemap.c:3455 #3: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #3: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #3: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: netif_receive_skb_list_internal+0x4a5/0xc50 net/core/dev.c:5788 #4: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #4: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #4: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x1c8/0x510 net/ipv4/ip_input.c:232 #5: ffff888028418cf0 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x2733/0x2e30 net/ipv4/tcp_ipv4.c:2110 #6: ffff8880b8e28418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999 #7: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #7: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #7: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline] #7: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0xf0/0x400 kernel/trace/bpf_trace.c:2325 stack backtrace: CPU: 0 PID: 7597 Comm: syz-executor Not tainted 6.1.142-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 check_noncircular+0x274/0x310 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 kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 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+0x184/0x870 kernel/rcu/tree.c:3402 trie_delete_elem+0x52d/0x690 kernel/bpf/lpm_trie.c:545 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:1001 [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:2285 [inline] bpf_trace_run3+0x1e3/0x400 kernel/trace/bpf_trace.c:2325 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x411/0x5c0 kernel/time/timer.c:609 __mod_timer+0x88e/0xd20 kernel/time/timer.c:1113 sk_reset_timer+0x1f/0xb0 net/core/sock.c:3374 tcp_event_new_data_sent+0x20e/0x370 net/ipv4/tcp_output.c:81 tcp_write_xmit+0x1780/0x62b0 net/ipv4/tcp_output.c:2716 __tcp_push_pending_frames+0x93/0x340 net/ipv4/tcp_output.c:2894 tcp_push_pending_frames include/net/tcp.h:1986 [inline] tcp_data_snd_check net/ipv4/tcp_input.c:5599 [inline] tcp_rcv_established+0xf62/0x1d30 net/ipv4/tcp_input.c:6023 tcp_v4_do_rcv+0x48d/0xb00 net/ipv4/tcp_ipv4.c:1683 tcp_v4_rcv+0x2789/0x2e30 net/ipv4/tcp_ipv4.c:2114 ip_protocol_deliver_rcu+0x3ad/0x780 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2c7/0x510 net/ipv4/ip_input.c:233 NF_HOOK+0x2ff/0x390 include/linux/netfilter.h:302 dst_input include/net/dst.h:463 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0xa30/0xd10 net/ipv4/ip_input.c:639 ip_list_rcv+0x3df/0x430 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5612 [inline] __netif_receive_skb_list_core+0x574/0x740 net/core/dev.c:5660 __netif_receive_skb_list net/core/dev.c:5712 [inline] netif_receive_skb_list_internal+0x90f/0xc50 net/core/dev.c:5803 gro_normal_list include/net/gro.h:433 [inline] napi_complete_done+0x37d/0x830 net/core/dev.c:6144 virtqueue_napi_complete drivers/net/virtio_net.c:403 [inline] virtnet_poll+0x991/0x1150 drivers/net/virtio_net.c:1687 __napi_poll+0xc0/0x460 net/core/dev.c:6578 napi_poll net/core/dev.c:6645 [inline] net_rx_action+0x5b1/0xad0 net/core/dev.c:6759 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:682 RIP: 0010:lock_release+0x593/0x910 kernel/locking/lockdep.c:5686 Code: 00 00 00 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 75 75 f7 44 24 50 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 2f 00 00 00 00 66 43 c7 44 2f 09 00 00 43 c6 44 2f 0b 00 RSP: 0000:ffffc900058c78e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 394e4298a39ac2a1 RCX: 11c664fd34424000 RDX: 0000000000000003 RSI: ffffffff8a6c1160 RDI: ffffffff8abf14a0 RBP: ffffc900058c79f0 R08: dffffc0000000000 R09: fffffbfff1bfd1a6 R10: fffffbfff1bfd1a6 R11: 1ffffffff1bfd1a5 R12: ffff8880583ca918 R13: dffffc0000000000 R14: ffff8880583ca890 R15: 1ffff92000b18f28 rcu_lock_release include/linux/rcupdate.h:355 [inline] rcu_read_unlock_sched include/linux/rcupdate.h:904 [inline] pfn_valid+0x3c5/0x420 include/linux/mmzone.h:1867 page_table_check_set+0x25/0x6d0 mm/page_table_check.c:108 page_table_check_pte_set include/linux/page_table_check.h:83 [inline] set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline] do_set_pte+0x452/0x460 mm/memory.c:4426 filemap_map_pages+0xcab/0x10d0 mm/filemap.c:3481 do_fault_around mm/memory.c:4600 [inline] do_read_fault mm/memory.c:4626 [inline] do_fault mm/memory.c:4760 [inline] handle_pte_fault mm/memory.c:5031 [inline] __handle_mm_fault mm/memory.c:5173 [inline] handle_mm_fault+0x2889/0x3e70 mm/memory.c:5294 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fa5da54d550 Code: Unable to access opcode bytes at 0x7fa5da54d526. RSP: 002b:00007ffdfbc2f078 EFLAGS: 00010206 RAX: 0000000000000008 RBX: 0000000000000000 RCX: 00007fa5da5851cd RDX: 0000000000000000 RSI: 0000000000000018 RDI: 000055557e2947e0 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055557e2947d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000043724 R15: 00007ffdfbc2f210 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: 9c pushf 5: 8f 84 24 80 00 00 00 pop 0x80(%rsp) c: f6 84 24 81 00 00 00 testb $0x2,0x81(%rsp) 13: 02 14: 75 75 jne 0x8b 16: f7 44 24 50 00 02 00 testl $0x200,0x50(%rsp) 1d: 00 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp) 28: e0 45 * 2a: 4b c7 04 2f 00 00 00 movq $0x0,(%r15,%r13,1) <-- trapping instruction 31: 00 32: 66 43 c7 44 2f 09 00 movw $0x0,0x9(%r15,%r13,1) 39: 00 3a: 43 c6 44 2f 0b 00 movb $0x0,0xb(%r15,%r13,1)