bisecting fixing commit since 189522da8b3a796d56d802e067d591d2ffff7f40 building syzkaller on 2e44d63e401ead7d7928c95a30d243b2de1a243b testing commit 189522da8b3a796d56d802e067d591d2ffff7f40 with gcc (GCC) 8.1.0 kernel signature: f753e38c6f4d04c36d0a0c8a99d7ba350853f9988412bd778cca3bcdf6bc5929 all runs: crashed: WARNING in ip_rt_bug testing current HEAD c85fb28b6f999db9928b841f63f1beeb3074eeca testing commit c85fb28b6f999db9928b841f63f1beeb3074eeca with gcc (GCC) 8.1.0 kernel signature: f22bf10eead86a98a2b502fda7e64e16a198bab448c316bb5c8e9dce3209881a all runs: crashed: WARNING in ip_rt_bug revisions tested: 2, total time: 18m41.531134001s (build: 11m7.350115567s, test: 6m54.100011041s) the crash still happens on HEAD commit msg: Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux crash: WARNING in ip_rt_bug ------------[ cut here ]------------ WARNING: CPU: 1 PID: 8321 at net/ipv4/route.c:1251 ip_rt_bug+0x8/0x10 net/ipv4/route.c:1250 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 8321 Comm: syz-executor.5 Not tainted 5.9.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xa3/0xcc lib/dump_stack.c:118 panic+0x135/0x31a kernel/panic.c:231 __warn.cold.13+0x20/0x25 kernel/panic.c:600 report_bug+0xc0/0xf0 lib/bug.c:198 handle_bug+0x35/0x90 arch/x86/kernel/traps.c:234 exc_invalid_op+0x13/0x60 arch/x86/kernel/traps.c:254 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536 RIP: 0010:ip_rt_bug+0x8/0x10 net/ipv4/route.c:1251 Code: 48 48 8b 53 50 48 85 d2 74 04 f0 ff 42 08 48 89 50 50 5b 41 5c 5d c3 90 66 2e 0f 1f 84 00 00 00 00 00 48 89 d7 e8 68 71 de ff <0f> 0b 31 c0 c3 0f 1f 00 48 8b 77 18 48 89 fa 48 c7 c7 00 19 53 84 RSP: 0018:ffffc90002d47a08 EFLAGS: 00010282 RAX: 0000000000000001 RBX: ffff88811d6a00c0 RCX: 0000000000000000 RDX: 0000000000000402 RSI: ffffffff842f5d40 RDI: 0000000000000286 RBP: ffffc90002d47b70 R08: 0000000000000001 R09: 0000000000000001 R10: ffff88810b89e580 R11: 692545c28bf8cd79 R12: 000000000000000c R13: 0000000000000000 R14: ffff8881203f092c R15: ffffc90002d47a90 ip_send_skb+0x10/0x40 net/ipv4/ip_output.c:1567 __icmp_send+0x45f/0x780 net/ipv4/icmp.c:740 icmp_send include/net/icmp.h:43 [inline] ip_options_compile+0x5c/0x70 net/ipv4/ip_options.c:486 ip_rcv_options net/ipv4/ip_input.c:278 [inline] ip_rcv_finish_core.isra.22+0x19e/0x650 net/ipv4/ip_input.c:370 ip_rcv_finish+0x5c/0xb0 net/ipv4/ip_input.c:426 NF_HOOK include/linux/netfilter.h:301 [inline] ip_rcv+0x58/0x200 net/ipv4/ip_input.c:539 __netif_receive_skb_one_core+0x53/0x70 net/core/dev.c:5286 netif_receive_skb_internal net/core/dev.c:5500 [inline] netif_receive_skb+0x90/0x390 net/core/dev.c:5559 tun_rx_batched.isra.56+0x18a/0x1f0 drivers/net/tun.c:1503 tun_get_user+0x102f/0x1580 drivers/net/tun.c:1957 tun_chr_write_iter+0x46/0x67 drivers/net/tun.c:1986 call_write_iter include/linux/fs.h:1882 [inline] new_sync_write+0x113/0x1a0 fs/read_write.c:503 vfs_write+0x19b/0x230 fs/read_write.c:586 ksys_write+0x5a/0xd0 fs/read_write.c:639 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c8a9 Code: 8d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f46cfd3dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000050cf00 RCX: 000000000045c8a9 RDX: 000000000000100c RSI: 0000000020000240 RDI: 0000000000000005 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d0f R14: 00000000004cf47f R15: 00007f46cfd3e6d4 Kernel Offset: disabled Rebooting in 86400 seconds..