watchdog: BUG: soft lockup - CPU#1 stuck for 134s! [syz-executor738:4553] Modules linked in: irq event stamp: 13885653 hardirqs last enabled at (13885652): [] restore_regs_and_return_to_kernel+0x0/0x2b hardirqs last disabled at (13885653): [] interrupt_entry+0xb5/0xf0 arch/x86/entry/entry_64.S:625 softirqs last enabled at (13614028): [] tun_napi_alloc_frags drivers/net/tun.c:1478 [inline] softirqs last enabled at (13614028): [] tun_get_user+0x1dd9/0x4290 drivers/net/tun.c:1825 softirqs last disabled at (13614032): [] tun_get_user+0x313f/0x4290 drivers/net/tun.c:1942 CPU: 1 PID: 4553 Comm: syz-executor738 Not tainted 4.17.0-rc3+ #40 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x20/0x50 kernel/kcov.c:101 RSP: 0018:ffff8801d8cfe250 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff8801d88a8080 RBX: ffff8801d7389e40 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffffff868da4ad RDI: ffff8801c8a53277 RBP: ffff8801d8cfe250 R08: ffff8801d88a8080 R09: ffff8801d8cfe3e8 R10: ffffed003b19fc87 R11: ffff8801d8cfe43f R12: ffff8801c8a5327f R13: 0000000000000000 R14: ffff8801c8a4e5fe R15: ffff8801d8cfe3e8 FS: 0000000000d88940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001acab3000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: _decode_session6+0xc1d/0x14f0 net/ipv6/xfrm6_policy.c:150 __xfrm_decode_session+0x71/0x140 net/xfrm/xfrm_policy.c:2368 xfrm_decode_session_reverse include/net/xfrm.h:1213 [inline] icmpv6_route_lookup+0x395/0x6e0 net/ipv6/icmp.c:372 icmp6_send+0x1982/0x2da0 net/ipv6/icmp.c:551 icmpv6_send+0x17a/0x300 net/ipv6/ip6_icmp.c:43 ip6_input_finish+0x14e1/0x1a30 net/ipv6/ip6_input.c:305 NF_HOOK include/linux/netfilter.h:288 [inline] ip6_input+0xe1/0x5e0 net/ipv6/ip6_input.c:327 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x29c/0xa10 net/ipv6/ip6_input.c:71 NF_HOOK include/linux/netfilter.h:288 [inline] ipv6_rcv+0xeb8/0x2040 net/ipv6/ip6_input.c:208 __netif_receive_skb_core+0x2468/0x3650 net/core/dev.c:4646 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4711 netif_receive_skb_internal+0x126/0x7b0 net/core/dev.c:4785 napi_frags_finish net/core/dev.c:5226 [inline] napi_gro_frags+0x631/0xc40 net/core/dev.c:5299 tun_get_user+0x3168/0x4290 drivers/net/tun.c:1951 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1996 call_write_iter include/linux/fs.h:1784 [inline] do_iter_readv_writev+0x859/0xa50 fs/read_write.c:680 do_iter_write+0x185/0x5f0 fs/read_write.c:959 vfs_writev+0x1c7/0x330 fs/read_write.c:1004 do_writev+0x112/0x2f0 fs/read_write.c:1039 __do_sys_writev fs/read_write.c:1112 [inline] __se_sys_writev fs/read_write.c:1109 [inline] __x64_sys_writev+0x75/0xb0 fs/read_write.c:1109 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x442c30 RSP: 002b:00007ffe3fff4978 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000442c30 RDX: 0000000000000001 RSI: 00007ffe3fff49c0 RDI: 00000000000000fc RBP: 0000000000d89940 R08: 0000000000000000 R09: 00007ffe000087fe R10: 0000000000000000 R11: 0000000000000246 R12: 585858582e72656c R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 Code: 89 4c d8 20 4c 89 08 5d c3 66 90 55 65 48 8b 04 25 c0 ed 01 00 65 8b 15 9f bd 88 7e 48 89 e5 81 e2 00 01 1f 00 48 8b 75 08 75 2b <8b> 90 78 12 00 00 83 fa 02 75 20 48 8b 88 80 12 00 00 8b 80 7c