Hello, syzbot found the following issue on: HEAD commit: c49243e8 Merge branch 'net-fix-issues-around-register_netd.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=11da7ba8d00000 kernel config: https://syzkaller.appspot.com/x/.config?x=bacfc914704718d3 dashboard link: https://syzkaller.appspot.com/bug?extid=2393580080a2da190f04 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13704c3f500000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=160cc357500000 The issue was bisected to: commit c269a24ce057abfc31130960e96ab197ef6ab196 Author: Jakub Kicinski <kuba@xxxxxxxxxx> Date: Wed Jan 6 18:40:06 2021 +0000 net: make free_netdev() more lenient with unregistering devices bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13901b50d00000 final oops: https://syzkaller.appspot.com/x/report.txt?x=10501b50d00000 console output: https://syzkaller.appspot.com/x/log.txt?x=17901b50d00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2393580080a2da190f04@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: c269a24ce057 ("net: make free_netdev() more lenient with unregistering devices") ------------[ cut here ]------------ kernel BUG at net/core/dev.c:10661! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8459 Comm: syz-executor375 Not tainted 5.11.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:free_netdev+0x4b3/0x5e0 net/core/dev.c:10661 Code: c0 01 38 d0 7c 08 84 d2 0f 85 1a 01 00 00 0f b7 83 32 02 00 00 48 29 c3 48 89 df e8 d7 77 ac fa e9 47 ff ff ff e8 3d 1e 80 fa <0f> 0b e8 36 1e 80 fa 0f b6 2d 39 e1 e8 05 31 ff 89 ee e8 a6 24 80 RSP: 0018:ffffc9000163f1a0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88802814a000 RCX: 0000000000000000 RDX: ffff888021678000 RSI: ffffffff86f25763 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff86f25683 R11: 0000000000000003 R12: ffff888028149ef8 R13: ffff88802814a058 R14: dffffc0000000000 R15: ffff888028149ef8 FS: 00000000010bf880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ade220a6d8 CR3: 0000000012719000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __rtnl_newlink+0x1484/0x16e0 net/core/rtnetlink.c:3447 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3491 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2345 ___sys_sendmsg+0xf3/0x170 net/socket.c:2399 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2432 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x4404b9 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff3e934f98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004404b9 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 0000000000000014 R09: 00000000004002c8 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000401cc0 R13: 0000000000401d50 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace ec4d68ff94a95202 ]--- RIP: 0010:free_netdev+0x4b3/0x5e0 net/core/dev.c:10661 Code: c0 01 38 d0 7c 08 84 d2 0f 85 1a 01 00 00 0f b7 83 32 02 00 00 48 29 c3 48 89 df e8 d7 77 ac fa e9 47 ff ff ff e8 3d 1e 80 fa <0f> 0b e8 36 1e 80 fa 0f b6 2d 39 e1 e8 05 31 ff 89 ee e8 a6 24 80 RSP: 0018:ffffc9000163f1a0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88802814a000 RCX: 0000000000000000 RDX: ffff888021678000 RSI: ffffffff86f25763 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff86f25683 R11: 0000000000000003 R12: ffff888028149ef8 R13: ffff88802814a058 R14: dffffc0000000000 R15: ffff888028149ef8 FS: 00000000010bf880(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd33803e118 CR3: 0000000012719000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
