bisecting fixing commit since c4ff839de17f38b0ae0f8983b5c5186f8a389238 building syzkaller on a57db36fe48aa500618c2eac3b38c27afe6d290f testing commit c4ff839de17f38b0ae0f8983b5c5186f8a389238 with gcc (GCC) 8.4.1 20210217 kernel signature: 0777fdcbcd0843f2e7a289cf1d8ea35549f085217e7b93d6b65f9eb196123248 all runs: crashed: general protection fault in hsr_dev_change_mtu testing current HEAD 3c8c23092588a23bf1856a64f58c37f477a413be testing commit 3c8c23092588a23bf1856a64f58c37f477a413be with gcc (GCC) 8.4.1 20210217 kernel signature: 71e4e41d6081b1701a76c5856af6697a048a29b0cb7c28b82b3f75c9920ff896 all runs: crashed: general protection fault in hsr_dev_change_mtu revisions tested: 2, total time: 26m58.560167648s (build: 19m47.893614467s, test: 6m29.057158485s) the crash still happens on HEAD commit msg: Linux 4.19.190 crash: general protection fault in hsr_dev_change_mtu netlink: 'syz-executor.4': attribute type 10 has an invalid length. bond0: enslaved VLAN challenged slave hsr4. Adding VLANs will be blocked as long as hsr4 is part of bond bond0 bond0: The slave device specified does not support setting the MAC address kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 9970 Comm: syz-executor.4 Not tainted 4.19.190-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hsr_dev_change_mtu+0x87/0xb0 net/hsr/hsr_device.c:149 Code: 02 00 00 31 c0 5b 41 5c 41 5d 41 5e 5d c3 e8 e0 76 12 fa eb e7 49 8d 7e 10 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 1c 49 8b 7e 10 ba 06 00 00 00 48 c7 c6 40 d0 fe 88 RSP: 0018:ffff8880b4b3e970 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8880b4a8c100 RCX: 1ffff110168a45bf RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000010 RBP: ffff8880b4b3e990 R08: 0000000000000000 R09: ffffed1017464552 R10: ffffed1017464552 R11: ffff8880ba322a93 R12: ffff8880b4a8cbc0 R13: 00000000000005dc R14: 0000000000000000 R15: ffffffff88fed220 FS: 00007f19150bf700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000017b8708 CR3: 0000000098659000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __dev_set_mtu net/core/dev.c:7755 [inline] dev_set_mtu_ext+0x257/0x530 net/core/dev.c:7808 dev_set_mtu+0x87/0xe0 net/core/dev.c:7832 bond_enslave+0x679/0x4c90 drivers/net/bonding/bond_main.c:1530 do_set_master net/core/rtnetlink.c:2321 [inline] do_set_master+0x171/0x200 net/core/rtnetlink.c:2295 do_setlink+0x94c/0x2ec0 net/core/rtnetlink.c:2455 rtnl_newlink+0x975/0x1360 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+0x667/0xc60 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: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f19150bf188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000020000600 RDI: 0000000000000005 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007ffd86b6564f R14: 00007f19150bf300 R15: 0000000000022000 Modules linked in: ---[ end trace 40db23aef2627a71 ]--- RIP: 0010:hsr_dev_change_mtu+0x87/0xb0 net/hsr/hsr_device.c:149 Code: 02 00 00 31 c0 5b 41 5c 41 5d 41 5e 5d c3 e8 e0 76 12 fa eb e7 49 8d 7e 10 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 1c 49 8b 7e 10 ba 06 00 00 00 48 c7 c6 40 d0 fe 88 RSP: 0018:ffff8880b4b3e970 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8880b4a8c100 RCX: 1ffff110168a45bf RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000010 RBP: ffff8880b4b3e990 R08: 0000000000000000 R09: ffffed1017464552 R10: ffffed1017464552 R11: ffff8880ba322a93 R12: ffff8880b4a8cbc0 R13: 00000000000005dc R14: 0000000000000000 R15: ffffffff88fed220 FS: 00007f19150bf700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000017b8708 CR3: 0000000098659000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400