bisecting fixing commit since 4707d8e5727387e36ea99c74d5ff0ad227700fd0 building syzkaller on c3e9afb345d6b479ca401f18ceba6f7ae43e45ab testing commit 4707d8e5727387e36ea99c74d5ff0ad227700fd0 with gcc (GCC) 8.1.0 kernel signature: 0ea1749103c76742eecc01a33e7b2d08dc55ae362f4eacd1d46d81b98f0c70b3 all runs: crashed: general protection fault in nfnetlink_parse_nat_setup testing current HEAD 399849e4654ea496a6217ba4e5ee3d304c995ab4 testing commit 399849e4654ea496a6217ba4e5ee3d304c995ab4 with gcc (GCC) 8.1.0 kernel signature: 13cdd2c1652a81f6baf6b03125d510f70c173a430021e6b4b278f4bd91196a1c all runs: crashed: general protection fault in nfnetlink_parse_nat_setup revisions tested: 2, total time: 25m14.074397416s (build: 18m26.388717111s, test: 6m3.545888381s) the crash still happens on HEAD commit msg: Linux 4.19.131 crash: general protection fault in nfnetlink_parse_nat_setup IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready netlink: 20 bytes leftover after parsing attributes in process `syz-executor.2'. 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: 7913 Comm: syz-executor.2 Not tainted 4.19.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:nfnetlink_parse_nat net/netfilter/nf_nat_core.c:847 [inline] RIP: 0010:nfnetlink_parse_nat_setup+0x1dd/0x350 net/netfilter/nf_nat_core.c:884 Code: 00 00 4c 89 e7 83 e9 04 e8 b0 e4 ab fd 85 c0 0f 88 05 01 00 00 49 8d 7e 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 56 01 00 00 48 8b b5 e0 fe ff ff 4c 89 e7 41 ff RSP: 0018:ffff88808201eff0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000060000007 RSI: ffffffff87677d20 RDI: 000000030000003b RBP: ffff88808201f118 R08: ffffed1015d65081 R09: ffffed1015d65080 R10: ffffed1015d65080 R11: ffff8880aeb28407 R12: ffff88808201f090 R13: ffff8880a072a680 R14: 0000000300000003 R15: ffff88808201f0f0 FS: 00007f976526d700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe1580bf78 CR3: 00000000a85b5000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ctnetlink_parse_nat_setup+0x7c/0x430 net/netfilter/nf_conntrack_netlink.c:1521 ctnetlink_setup_nat net/netfilter/nf_conntrack_netlink.c:1596 [inline] ctnetlink_create_conntrack+0x3be/0xfd0 net/netfilter/nf_conntrack_netlink.c:1984 ctnetlink_new_conntrack+0x46c/0xe4e net/netfilter/nf_conntrack_netlink.c:2114 nfnetlink_rcv_msg+0x930/0xc00 net/netfilter/nfnetlink.c:228 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2455 nfnetlink_rcv+0x163/0x3b0 net/netfilter/nfnetlink.c:560 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 kernel_sendmsg+0x26/0x30 net/socket.c:640 sock_no_sendpage+0xfd/0x140 net/core/sock.c:2647 kernel_sendpage+0x60/0xd0 net/socket.c:3378 sock_sendpage+0x6d/0xd0 net/socket.c:847 pipe_to_sendpage+0x212/0x430 fs/splice.c:452 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x2cb/0x720 fs/splice.c:627 splice_from_pipe+0xbb/0x120 fs/splice.c:662 generic_splice_sendpage+0x10/0x20 fs/splice.c:833 do_splice_from fs/splice.c:852 [inline] do_splice fs/splice.c:1154 [inline] __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice+0x716/0x17d0 fs/splice.c:1408 __x64_sys_splice+0xdc/0x1a0 fs/splice.c:1408 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ca69 Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f976526cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000507a00 RCX: 000000000045ca69 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000078bfa0 R08: 000000000004ffe0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000bae R14: 00000000004cea37 R15: 00007f976526d6d4 Modules linked in: ---[ end trace c3000dc0d6036573 ]--- RIP: 0010:nfnetlink_parse_nat net/netfilter/nf_nat_core.c:847 [inline] RIP: 0010:nfnetlink_parse_nat_setup+0x1dd/0x350 net/netfilter/nf_nat_core.c:884 Code: 00 00 4c 89 e7 83 e9 04 e8 b0 e4 ab fd 85 c0 0f 88 05 01 00 00 49 8d 7e 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 56 01 00 00 48 8b b5 e0 fe ff ff 4c 89 e7 41 ff RSP: 0018:ffff88808201eff0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000060000007 RSI: ffffffff87677d20 RDI: 000000030000003b RBP: ffff88808201f118 R08: ffffed1015d65081 R09: ffffed1015d65080 R10: ffffed1015d65080 R11: ffff8880aeb28407 R12: ffff88808201f090 R13: ffff8880a072a680 R14: 0000000300000003 R15: ffff88808201f0f0 FS: 00007f976526d700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000078c000 CR3: 00000000a85b5000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400