ccid3_first_li: No RTT estimate available, using fallback RTT ccid3_first_li: X_recv==0 BUG: stored value of X_recv is zero at net/dccp/ccids/ccid3.c:691/ccid3_first_li() CPU: 0 PID: 10016 Comm: syz-executor.0 Not tainted 6.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106 ccid3_first_li+0x317/0x520 net/dccp/ccids/ccid3.c:691 tfrc_lh_interval_add+0x610/0x8e0 net/dccp/ccids/lib/loss_interval.c:157 tfrc_rx_handle_loss+0xe02/0x2080 net/dccp/ccids/lib/packet_history.c:328 ccid3_hc_rx_packet_recv+0x372/0xf10 net/dccp/ccids/ccid3.c:744 ccid_hc_rx_packet_recv net/dccp/ccid.h:182 [inline] dccp_deliver_input_to_ccids+0xe3/0x260 net/dccp/input.c:176 dccp_rcv_established net/dccp/input.c:374 [inline] dccp_rcv_established+0x106/0x160 net/dccp/input.c:364 dccp_v4_do_rcv+0x169/0x1a0 net/dccp/ipv4.c:675 sk_backlog_rcv include/net/sock.h:1121 [inline] __sk_receive_skb+0x2a8/0xba0 net/core/sock.c:571 dccp_v4_rcv+0x1282/0x1a00 net/dccp/ipv4.c:898 ip_protocol_deliver_rcu+0x9f/0x480 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2e4/0x510 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ip_local_deliver+0x1b6/0x550 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:468 [inline] ip_rcv_finish+0x1c4/0x2e0 net/ipv4/ip_input.c:449 NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ip_rcv+0xc9/0x430 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0x115/0x180 net/core/dev.c:5523 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5637 process_backlog+0x101/0x6b0 net/core/dev.c:5965 __napi_poll.constprop.0+0xb4/0x530 net/core/dev.c:6527 napi_poll net/core/dev.c:6594 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6727 __do_softirq+0x218/0x965 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1074 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5721 Code: c1 05 85 f6 99 7e 83 f8 01 0f 85 b0 02 00 00 9c 58 f6 c4 02 0f 85 9b 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90015b97538 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92002b72ea9 RCX: 0000000000000001 RDX: 1ffff1100590c8c8 RSI: ffffffff8a8cad80 RDI: ffffffff8ae93020 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff233e1d0 R10: ffffffff919f0e87 R11: 1ffff110049267fa R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8cbab2a0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:303 [inline] rcu_read_lock include/linux/rcupdate.h:749 [inline] page_ext_get+0x3a/0x310 mm/page_ext.c:508 page_table_check_clear mm/page_table_check.c:72 [inline] page_table_check_clear+0x1b1/0x9a0 mm/page_table_check.c:61 __page_table_check_pte_clear+0xef/0x100 mm/page_table_check.c:158 page_table_check_pte_clear include/linux/page_table_check.h:49 [inline] ptep_get_and_clear_full arch/x86/include/asm/pgtable.h:1293 [inline] zap_pte_range mm/memory.c:1431 [inline] zap_pmd_range mm/memory.c:1573 [inline] zap_pud_range mm/memory.c:1602 [inline] zap_p4d_range mm/memory.c:1623 [inline] unmap_page_range+0x18e0/0x2c10 mm/memory.c:1644 unmap_single_vma+0x194/0x2b0 mm/memory.c:1690 unmap_vmas+0x1e2/0x330 mm/memory.c:1731 exit_mmap+0x1ad/0xa60 mm/mmap.c:3210 __mmput+0x12a/0x4d0 kernel/fork.c:1349 mmput+0x62/0x70 kernel/fork.c:1371 exit_mm kernel/exit.c:567 [inline] do_exit+0x9ad/0x2a20 kernel/exit.c:861 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024 get_signal+0x23ba/0x2790 kernel/signal.c:2892 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296 __do_fast_syscall_32+0x6d/0xe0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 RIP: 0023:0xf7fb9579 Code: Unable to access opcode bytes at 0xf7fb954f. RSP: 002b:00000000f7fb466c EFLAGS: 00000246 ORIG_RAX: 00000000000000f0 RAX: 0000000000000001 RBX: 00000000f737afcc RCX: 0000000000000081 RDX: 00000000000f4240 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000f7219d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun ---------------- Code disassembly (best guess): 0: c1 05 85 f6 99 7e 83 roll $0x83,0x7e99f685(%rip) # 0x7e99f68c 7: f8 clc 8: 01 0f add %ecx,(%rdi) a: 85 b0 02 00 00 9c test %esi,-0x63fffffe(%rax) 10: 58 pop %rax 11: f6 c4 02 test $0x2,%ah 14: 0f 85 9b 02 00 00 jne 0x2b5 1a: 48 85 ed test %rbp,%rbp 1d: 74 01 je 0x20 1f: fb sti 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 27: fc ff df * 2a: 48 01 c3 add %rax,%rbx <-- trapping instruction 2d: 48 c7 03 00 00 00 00 movq $0x0,(%rbx) 34: 48 c7 43 08 00 00 00 movq $0x0,0x8(%rbx) 3b: 00 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 84 .byte 0x84 3f: 24 .byte 0x24