================================================================== BUG: KCSAN: data-race in ip_tunnel_xmit / ip_tunnel_xmit write to 0xffff88812ffc9170 of 8 bytes by interrupt on cpu 0: ip_tunnel_xmit+0x7a6/0x11c0 net/ipv4/ip_tunnel.c:756 sit_tunnel_xmit__ net/ipv6/sit.c:1058 [inline] sit_tunnel_xmit+0x3c2/0x11f0 net/ipv6/sit.c:1074 __netdev_start_xmit include/linux/netdevice.h:4944 [inline] netdev_start_xmit include/linux/netdevice.h:4958 [inline] xmit_one+0xf9/0x270 net/core/dev.c:3654 dev_hard_start_xmit net/core/dev.c:3670 [inline] __dev_queue_xmit+0xd44/0x1300 net/core/dev.c:4245 dev_queue_xmit+0x13/0x20 net/core/dev.c:4278 neigh_connected_output+0x264/0x290 net/core/neighbour.c:1524 neigh_output include/net/neighbour.h:510 [inline] ip_finish_output2+0x874/0xb10 net/ipv4/ip_output.c:230 __ip_finish_output net/ipv4/ip_output.c:252 [inline] ip_finish_output+0x2fa/0x490 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_output+0xf6/0x1a0 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:448 [inline] ip_local_out+0x167/0x230 net/ipv4/ip_output.c:126 __ip_queue_xmit+0x97f/0x9a0 net/ipv4/ip_output.c:533 ip_queue_xmit+0x34/0x40 net/ipv4/ip_output.c:547 __tcp_transmit_skb+0x141a/0x19f0 net/ipv4/tcp_output.c:1405 tcp_transmit_skb net/ipv4/tcp_output.c:1423 [inline] tcp_xmit_probe_skb net/ipv4/tcp_output.c:4009 [inline] tcp_write_wakeup+0x28f/0x810 net/ipv4/tcp_output.c:4061 tcp_send_probe0+0x2c/0x2b0 net/ipv4/tcp_output.c:4077 tcp_probe_timer net/ipv4/tcp_timer.c:398 [inline] tcp_write_timer_handler+0x394/0x530 net/ipv4/tcp_timer.c:626 tcp_write_timer+0xb9/0x180 net/ipv4/tcp_timer.c:642 call_timer_fn+0x2e/0x1d0 kernel/time/timer.c:1431 expire_timers+0x135/0x250 kernel/time/timer.c:1476 __run_timers+0x358/0x420 kernel/time/timer.c:1745 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1758 __do_softirq+0x12c/0x275 kernel/softirq.c:559 invoke_softirq kernel/softirq.c:433 [inline] __irq_exit_rcu+0xa5/0xb0 kernel/softirq.c:637 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 should_watch kernel/kcsan/core.c:269 [inline] check_access kernel/kcsan/core.c:632 [inline] __tsan_read2+0x150/0x180 kernel/kcsan/core.c:843 tlb_flush_pte_range include/asm-generic/tlb.h:524 [inline] zap_pte_range+0x39c/0xe20 mm/memory.c:1256 zap_pmd_range mm/memory.c:1374 [inline] zap_pud_range mm/memory.c:1403 [inline] zap_p4d_range mm/memory.c:1424 [inline] unmap_page_range+0x2dc/0x3d0 mm/memory.c:1445 unmap_single_vma+0x157/0x210 mm/memory.c:1490 unmap_vmas+0xc0/0x170 mm/memory.c:1522 exit_mmap+0x1be/0x400 mm/mmap.c:3224 __mmput+0x27/0x1c0 kernel/fork.c:1096 mmput+0x3d/0x50 kernel/fork.c:1117 exit_mm+0x360/0x450 kernel/exit.c:502 do_exit+0x3ff/0x1560 kernel/exit.c:813 do_group_exit+0xce/0x1a0 kernel/exit.c:923 get_signal+0xfc3/0x1610 kernel/signal.c:2818 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88812ffc9170 of 8 bytes by interrupt on cpu 1: ip_tunnel_xmit+0x794/0x11c0 net/ipv4/ip_tunnel.c:756 sit_tunnel_xmit__ net/ipv6/sit.c:1058 [inline] sit_tunnel_xmit+0x3c2/0x11f0 net/ipv6/sit.c:1074 __netdev_start_xmit include/linux/netdevice.h:4944 [inline] netdev_start_xmit include/linux/netdevice.h:4958 [inline] xmit_one+0xf9/0x270 net/core/dev.c:3654 dev_hard_start_xmit net/core/dev.c:3670 [inline] __dev_queue_xmit+0xd44/0x1300 net/core/dev.c:4245 dev_queue_xmit+0x13/0x20 net/core/dev.c:4278 neigh_connected_output+0x264/0x290 net/core/neighbour.c:1524 neigh_output include/net/neighbour.h:510 [inline] ip_finish_output2+0x874/0xb10 net/ipv4/ip_output.c:230 __ip_finish_output net/ipv4/ip_output.c:252 [inline] ip_finish_output+0x2fa/0x490 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_output+0xf6/0x1a0 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:448 [inline] ip_local_out+0x167/0x230 net/ipv4/ip_output.c:126 __ip_queue_xmit+0x97f/0x9a0 net/ipv4/ip_output.c:533 ip_queue_xmit+0x34/0x40 net/ipv4/ip_output.c:547 __tcp_transmit_skb+0x141a/0x19f0 net/ipv4/tcp_output.c:1405 tcp_transmit_skb net/ipv4/tcp_output.c:1423 [inline] tcp_xmit_probe_skb net/ipv4/tcp_output.c:4009 [inline] tcp_write_wakeup+0x4a9/0x810 net/ipv4/tcp_output.c:4062 tcp_send_probe0+0x2c/0x2b0 net/ipv4/tcp_output.c:4077 tcp_probe_timer net/ipv4/tcp_timer.c:398 [inline] tcp_write_timer_handler+0x394/0x530 net/ipv4/tcp_timer.c:626 tcp_write_timer+0xb9/0x180 net/ipv4/tcp_timer.c:642 call_timer_fn+0x2e/0x1d0 kernel/time/timer.c:1431 expire_timers+0x135/0x250 kernel/time/timer.c:1476 __run_timers+0x358/0x420 kernel/time/timer.c:1745 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1758 __do_softirq+0x12c/0x275 kernel/softirq.c:559 invoke_softirq kernel/softirq.c:433 [inline] __irq_exit_rcu+0xa5/0xb0 kernel/softirq.c:637 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 __sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:193 selinux_inode_permission+0x27/0x430 security/selinux/hooks.c:3181 security_inode_permission+0x72/0xc0 security/security.c:1312 inode_permission+0x91/0x290 fs/namei.c:521 may_lookup fs/namei.c:1655 [inline] link_path_walk+0x17d/0x780 fs/namei.c:2211 path_lookupat+0x7b/0x570 fs/namei.c:2420 filename_lookup+0xff/0x390 fs/namei.c:2454 user_path_at_empty+0x3b/0x50 fs/namei.c:2734 do_readlinkat+0x87/0x200 fs/stat.c:425 __do_sys_readlink fs/stat.c:458 [inline] __se_sys_readlink fs/stat.c:455 [inline] __x64_sys_readlink+0x43/0x50 fs/stat.c:455 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 1030 Comm: systemd-udevd Not tainted 5.12.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================