==================================================================
BUG: KMSAN: uninit-value in do_error_trap+0x39b/0x600 arch/x86/kernel/traps.c:297
CPU: 0 PID: 4553 Comm: syz-executor266 Not tainted 4.16.0+ #87
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
 do_error_trap+0x39b/0x600 arch/x86/kernel/traps.c:297
 do_invalid_op+0x46/0x50 arch/x86/kernel/traps.c:316
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986
RIP: 0010:tcp_sacktag_write_queue+0x453b/0x4610 net/ipv4/tcp_input.c:1804
RSP: 0018:ffff88019a35f1a0 EFLAGS: 00010293
RAX: ffffffff88519d4b RBX: 0000000000000000 RCX: ffff8801ca588000
RDX: 0000000000000000 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff88019a35f358 R08: 0000000000000000 R09: 000077ff80000000
R10: 0000000000000001 R11: ffff88019a350000 R12: 0000000000000009
R13: 0000000000000000 R14: 0000000000000000 R15: 000000000000000a
 tcp_ack+0x20e8/0x8800 net/ipv4/tcp_input.c:3582
 tcp_rcv_established+0xfc1/0x2bb0 net/ipv4/tcp_input.c:5457
 tcp_v4_do_rcv+0x6cd/0xd90 net/ipv4/tcp_ipv4.c:1469
 sk_backlog_rcv include/net/sock.h:908 [inline]
 __release_sock+0x2d6/0x680 net/core/sock.c:2271
 release_sock+0x97/0x2a0 net/core/sock.c:2786
 tcp_sendmsg+0xd6/0x100 net/ipv4/tcp.c:1464
 inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg net/socket.c:640 [inline]
 sock_write_iter+0x3b9/0x470 net/socket.c:909
 do_iter_readv_writev+0x84d/0xa00 include/linux/fs.h:1776
 do_iter_write+0x30d/0xd40 fs/read_write.c:932
 vfs_writev fs/read_write.c:977 [inline]
 do_writev+0x3c9/0x830 fs/read_write.c:1012
 SYSC_writev+0x9b/0xb0 fs/read_write.c:1085
 SyS_writev+0x56/0x80 fs/read_write.c:1082
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x440419
RSP: 002b:00007ffd837374b8 EFLAGS: 00000217 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440419
RDX: 0000000000000001 RSI: 00000000200006c0 RDI: 0000000000000003
RBP: 00000000006cb018 R08: 0000000000000010 R09: 0000000000000010
R10: 0000000000000182 R11: 0000000000000217 R12: 0000000000401d40
R13: 0000000000401dd0 R14: 0000000000000000 R15: 0000000000000000

Local variable description: ----flags.i.i.i.i.i.i@__kmalloc
Variable was created at:
 __kmalloc+0x3c/0x350 mm/slub.c:3772
 kmalloc include/linux/slab.h:517 [inline]
 tcpm_new net/ipv4/tcp_metrics.c:182 [inline]
 tcp_get_metrics+0x1869/0x2c70 net/ipv4/tcp_metrics.c:309
==================================================================