[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   29.304488] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   35.074917] random: sshd: uninitialized urandom read (32 bytes read)
[   35.642919] random: sshd: uninitialized urandom read (32 bytes read)
[   36.740172] random: sshd: uninitialized urandom read (32 bytes read)
[  810.289445] random: sshd: uninitialized urandom read (32 bytes read)
[  815.824744] random: sshd: uninitialized urandom read (32 bytes read)
[  815.846704] Not allocated shadow for addr ffff8801d3e64000 (page ffffea000af76580)
[  815.854440] Attempted to access 270 bytes
[  815.858585] ------------[ cut here ]------------
[  815.863333] kernel BUG at mm/kmsan/kmsan.c:1344!
[  815.868115] invalid opcode: 0000 [#1] SMP PTI
[  815.872587] Dumping ftrace buffer:
[  815.876103]    (ftrace buffer empty)
[  815.879788] Modules linked in:
[  815.882995] CPU: 1 PID: 4536 Comm: sshd Not tainted 4.17.0-rc5+ #102
[  815.889459] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  815.898847] RIP: 0010:kmsan_get_shadow_address+0x1ce/0x1f0
[  815.904443] RSP: 0018:ffff8801d780e6f0 EFLAGS: 00010082
[  815.909782] RAX: 000000000000001d RBX: 0000000000000740 RCX: 0000000000000000
[  815.917033] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
[  815.924288] RBP: ffff8801d780e708 R08: 0000000000000000 R09: 0000000000000001
[  815.931545] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d3e64000
[  815.938792] R13: 000000000000010e R14: 0000000000000001 R15: 000000000000010e
[  815.946042] FS:  00007f5c08d837c0(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
[  815.954262] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  815.960121] CR2: 00007f5c081d6f70 CR3: 00000001ca410000 CR4: 00000000001406e0
[  815.967546] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  815.974804] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  815.982050] Call Trace:
[  815.984625]  kmsan_internal_unpoison_shadow+0x5c/0xe0
[  815.989796]  kmsan_unpoison_shadow+0x66/0xb0
[  815.994244]  virtqueue_get_buf_ctx+0x73f/0xa20
[  815.998808]  virtqueue_get_buf+0x72/0x90
[  816.002877]  start_xmit+0x293/0x29b0
[  816.006600]  ? packet_rcv+0x21a0/0x21a0
[  816.010556]  ? virtnet_close+0x2c0/0x2c0
[  816.014628]  dev_hard_start_xmit+0x5f1/0xc70
[  816.019065]  sch_direct_xmit+0x578/0x8f0
[  816.023108]  __qdisc_run+0x1785/0x3730
[  816.026978]  __dev_queue_xmit+0x1d50/0x3510
[  816.031281]  dev_queue_xmit+0x4b/0x60
[  816.035069]  ip_finish_output2+0x12bf/0x1490
[  816.039480]  ip_finish_output+0xcaf/0xff0
[  816.043610]  ip_output+0x505/0x5d0
[  816.047125]  ? ip_mc_finish_output+0x3b0/0x3b0
[  816.051689]  ? ip_finish_output+0xff0/0xff0
[  816.055984]  ip_queue_xmit+0x1a1d/0x1d10
[  816.060024]  ? __msan_metadata_ptr_for_store_1+0x13/0x20
[  816.065453]  ? __skb_clone+0x6ec/0x990
[  816.069320]  ? kmsan_set_origin+0x9e/0x160
[  816.073542]  ? ip_output+0x5d0/0x5d0
[  816.077233]  tcp_transmit_skb+0x3d6d/0x53b0
[  816.081541]  tcp_write_xmit+0x2d71/0xb1f0
[  816.085677]  __tcp_push_pending_frames+0x124/0x400
[  816.090585]  tcp_push+0x803/0x8f0
[  816.094033]  tcp_sendmsg_locked+0x4eb1/0x6610
[  816.098513]  tcp_sendmsg+0xb2/0x100
[  816.102115]  ? tcp_sendmsg_locked+0x6610/0x6610
[  816.106797]  inet_sendmsg+0x3f7/0x750
[  816.110588]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[  816.115936]  ? inet_getname+0x4a0/0x4a0
[  816.119896]  sock_write_iter+0x3b7/0x470
[  816.123936]  ? sock_read_iter+0x480/0x480
[  816.128069]  __vfs_write+0x7fb/0x9f0
[  816.131766]  vfs_write+0x467/0x8c0
[  816.135285]  __x64_sys_write+0x1bf/0x3e0
[  816.139329]  do_syscall_64+0x152/0x230
[  816.143232]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  816.148398] RIP: 0033:0x7f5c0711e370
[  816.152085] RSP: 002b:00007ffe00a85698 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  816.159776] RAX: ffffffffffffffda RBX: 0000000000000138 RCX: 00007f5c0711e370
[  816.167021] RDX: 0000000000000138 RSI: 000055e7de97d440 RDI: 0000000000000003
[  816.174268] RBP: 000055e7de97d440 R08: 000055e7de97b4e0 R09: 000055e7ddcc7820
[  816.181514] R10: 000000003d33ed55 R11: 0000000000000246 R12: 00007ffe00a856fc
[  816.188760] R13: 0000000000000001 R14: 000055e7de9834a0 R15: 0000000000000000
[  816.196017] 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 
[  816.215104] RIP: kmsan_get_shadow_address+0x1ce/0x1f0 RSP: ffff8801d780e6f0
[  816.222193] ---[ end trace dc8cbaab39a4d699 ]---
[  816.226922] Kernel panic - not syncing: Fatal exception in interrupt
[  816.233819] Dumping ftrace buffer:
[  816.237342]    (ftrace buffer empty)
[  816.241086] Kernel Offset: disabled
[  816.244691] Rebooting in 86400 seconds..