[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   30.562707] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   46.438711] random: sshd: uninitialized urandom read (32 bytes read)
[   46.932634] random: sshd: uninitialized urandom read (32 bytes read)
[   47.778140] random: sshd: uninitialized urandom read (32 bytes read)
[  121.176080] random: sshd: uninitialized urandom read (32 bytes read)
[  126.648094] random: sshd: uninitialized urandom read (32 bytes read)
[  126.669389] Not allocated shadow for addr ffff8801a1600000 (page ffffea0009c84000)
[  126.677113] Attempted to access 782 bytes
[  126.681251] ------------[ cut here ]------------
[  126.685989] kernel BUG at mm/kmsan/kmsan.c:1344!
[  126.690738] invalid opcode: 0000 [#1] SMP PTI
[  126.695205] Dumping ftrace buffer:
[  126.698727]    (ftrace buffer empty)
[  126.702412] Modules linked in:
[  126.705582] CPU: 0 PID: 4535 Comm: sshd Not tainted 4.17.0-rc5+ #102
[  126.712047] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  126.721394] RIP: 0010:kmsan_get_shadow_address+0x1ce/0x1f0
[  126.727006] RSP: 0018:ffff8801c9b3e6f0 EFLAGS: 00010082
[  126.732343] RAX: 000000000000001d RBX: 0000000000000680 RCX: 0000000000000000
[  126.739588] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
[  126.746831] RBP: ffff8801c9b3e708 R08: 0000000000000000 R09: 0000000000000001
[  126.754075] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801a1600000
[  126.761319] R13: 000000000000030e R14: 0000000000000001 R15: 000000000000030e
[  126.768565] FS:  00007fa488b107c0(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
[  126.776773] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  126.782628] CR2: 00007fa487f63f70 CR3: 00000001a5b98000 CR4: 00000000001406f0
[  126.789874] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  126.797119] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  126.804361] Call Trace:
[  126.806926]  kmsan_internal_unpoison_shadow+0x5c/0xe0
[  126.812092]  kmsan_unpoison_shadow+0x66/0xb0
[  126.816479]  virtqueue_get_buf_ctx+0x73f/0xa20
[  126.821043]  virtqueue_get_buf+0x72/0x90
[  126.825078]  start_xmit+0x293/0x29b0
[  126.828772]  ? packet_rcv+0x21a0/0x21a0
[  126.832723]  ? virtnet_close+0x2c0/0x2c0
[  126.836771]  dev_hard_start_xmit+0x5f1/0xc70
[  126.841163]  sch_direct_xmit+0x578/0x8f0
[  126.845203]  __qdisc_run+0x1785/0x3730
[  126.849074]  __dev_queue_xmit+0x1d50/0x3510
[  126.853376]  dev_queue_xmit+0x4b/0x60
[  126.857151]  ip_finish_output2+0x12bf/0x1490
[  126.861551]  ip_finish_output+0xcaf/0xff0
[  126.865676]  ip_output+0x505/0x5d0
[  126.869194]  ? ip_mc_finish_output+0x3b0/0x3b0
[  126.873752]  ? ip_finish_output+0xff0/0xff0
[  126.878058]  ip_queue_xmit+0x1a1d/0x1d10
[  126.882116]  ? __msan_metadata_ptr_for_store_1+0x13/0x20
[  126.887544]  ? __skb_clone+0x6ec/0x990
[  126.891408]  ? kmsan_set_origin+0x9e/0x160
[  126.895618]  ? ip_output+0x5d0/0x5d0
[  126.899307]  tcp_transmit_skb+0x3d6d/0x53b0
[  126.903608]  tcp_write_xmit+0x2d71/0xb1f0
[  126.907742]  __tcp_push_pending_frames+0x124/0x400
[  126.912655]  tcp_push+0x803/0x8f0
[  126.916084]  tcp_sendmsg_locked+0x4eb1/0x6610
[  126.920564]  tcp_sendmsg+0xb2/0x100
[  126.924167]  ? tcp_sendmsg_locked+0x6610/0x6610
[  126.928811]  inet_sendmsg+0x3f7/0x750
[  126.932586]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[  126.937924]  ? inet_getname+0x4a0/0x4a0
[  126.941870]  sock_write_iter+0x3b7/0x470
[  126.945908]  ? sock_read_iter+0x480/0x480
[  126.950031]  __vfs_write+0x7fb/0x9f0
[  126.953723]  vfs_write+0x467/0x8c0
[  126.957241]  __x64_sys_write+0x1bf/0x3e0
[  126.961277]  do_syscall_64+0x152/0x230
[  126.965153]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  126.970317] RIP: 0033:0x7fa486eab370
[  126.974008] RSP: 002b:00007ffe58777868 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  126.981698] RAX: ffffffffffffffda RBX: 0000000000000138 RCX: 00007fa486eab370
[  126.988942] RDX: 0000000000000138 RSI: 0000558544512440 RDI: 0000000000000003
[  126.996186] RBP: 0000558544512440 R08: 0000558544510240 R09: 0000558542565820
[  127.003434] R10: 00000000b0e933ad R11: 0000000000000246 R12: 00007ffe587778cc
[  127.010678] R13: 0000000000000001 R14: 00005585445184a0 R15: 0000000000000000
[  127.017927] Code: 75 29 48 c7 c7 83 00 a0 8a 31 c0 e8 7d 14 83 ff 80 3c 25 f8 73 53 8b 00 75 11 48 c7 c7 b3 00 a0 8a 31 c0 4c 89 fe e8 62 14 83 ff <0f> 0b eb fe 48 3d ff ff ff 1f 0f 87 a2 fe ff ff 48 8b 1c 25 10 
[  127.037017] RIP: kmsan_get_shadow_address+0x1ce/0x1f0 RSP: ffff8801c9b3e6f0
[  127.044099] ---[ end trace 08ff0b45faec878c ]---
[  127.049420] Kernel panic - not syncing: Fatal exception in interrupt
[  127.056431] Dumping ftrace buffer:
[  127.059951]    (ftrace buffer empty)
[  127.063636] Kernel Offset: disabled
[  127.067239] Rebooting in 86400 seconds..