bisecting fixing commit since 13af6c74b14a883366e7702c40c52ff548096e7f building syzkaller on 96dd36234d97bbf6b403f3a7f03cfc0296422879 testing commit 13af6c74b14a883366e7702c40c52ff548096e7f with gcc (GCC) 8.1.0 kernel signature: 7adbb49d4254ad7d421e1b6276849fdaf5f212c6d4b5072a22dcaf20af252a4b all runs: crashed: WARNING in dev_change_net_namespace testing current HEAD f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a testing commit f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a with gcc (GCC) 8.1.0 kernel signature: a9039f0ba346a90b48c895aa3f1cd53328b54d8e69b6ac57deb086040ef0d1db all runs: crashed: WARNING in dev_change_net_namespace revisions tested: 2, total time: 28m52.199496116s (build: 20m1.532770278s, test: 7m25.593540038s) the crash still happens on HEAD commit msg: Linux 4.19.142 crash: WARNING in dev_change_net_namespace RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 00007f95ef8d7ca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016 R13: 00007ffd3436eaff R14: 00007f95ef8d89c0 R15: 000000000078bfac ------------[ cut here ]------------ WARNING: CPU: 0 PID: 8750 at net/core/dev.c:9439 dev_change_net_namespace.cold.57+0xc/0x13 net/core/dev.c:9439 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8750 Comm: syz-executor.5 Not tainted 4.19.142-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+0x17c/0x22a lib/dump_stack.c:118 panic+0x1cd/0x375 kernel/panic.c:186 __warn.cold.7+0x1b/0x3e kernel/panic.c:541 report_bug+0x1a4/0x200 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x200/0x350 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038 RIP: 0010:dev_change_net_namespace.cold.57+0xc/0x13 net/core/dev.c:9439 Code: fc 48 c7 c7 20 71 c0 87 e8 ce d0 6a 01 e8 99 6f 29 fc 48 c7 c7 e0 70 c0 87 e8 bd d0 6a 01 48 c7 c7 a0 43 c0 87 e8 01 33 e6 fb <0f> 0b e9 4d 00 fe ff 89 c1 48 89 da 48 c7 c6 20 6f c0 87 48 c7 c7 RSP: 0018:ffff88807336ecb8 EFLAGS: 00010286 RAX: 0000000000000024 RBX: ffff8880904f0b00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff876783e0 RDI: ffffffff8a1a3a60 RBP: ffff88807336edd8 R08: ffffed1015d45081 R09: ffffed1015d45080 R10: ffffed1015d45080 R11: ffff8880aea28407 R12: ffffffff88f8bb80 R13: ffff8880904f0ba8 R14: ffff8880904f0b98 R15: 0000000000000067 do_setlink+0x1de/0x2ec0 net/core/rtnetlink.c:2354 rtnl_newlink+0xa1d/0x1320 net/core/rtnetlink.c:3077 rtnetlink_rcv_msg+0x34f/0x950 net/core/rtnetlink.c:4778 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2455 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4796 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x666/0xc50 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:632 ___sys_sendmsg+0x647/0x950 net/socket.c:2115 __sys_sendmsg+0xd9/0x180 net/socket.c:2153 __do_sys_sendmsg net/socket.c:2162 [inline] __se_sys_sendmsg net/socket.c:2160 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2160 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45cc79 Code: 2d 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 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f95ef8d7c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000002c080 RCX: 000000000045cc79 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 00007f95ef8d7ca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016 R13: 00007ffd3436eaff R14: 00007f95ef8d89c0 R15: 000000000078bfac Kernel Offset: disabled Rebooting in 86400 seconds..