[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   29.461130] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   30.950877] random: sshd: uninitialized urandom read (32 bytes read)
[   31.373842] random: sshd: uninitialized urandom read (32 bytes read)
[   32.500523] random: sshd: uninitialized urandom read (32 bytes read)
[  214.492428] random: sshd: uninitialized urandom read (32 bytes read)
[  220.002621] random: sshd: uninitialized urandom read (32 bytes read)
[  220.026025] Not allocated shadow for addr ffff8801d3b24000 (page ffffea000af62d80)
[  220.033756] Attempted to access 782 bytes
[  220.037910] ------------[ cut here ]------------
[  220.042646] kernel BUG at mm/kmsan/kmsan.c:1344!
[  220.047836] invalid opcode: 0000 [#1] SMP PTI
[  220.052304] Dumping ftrace buffer:
[  220.055830]    (ftrace buffer empty)
[  220.059523] Modules linked in:
[  220.063823] CPU: 0 PID: 4466 Comm: sshd Not tainted 4.17.0-rc5+ #102
[  220.070295] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  220.079635] RIP: 0010:kmsan_get_shadow_address+0x1ce/0x1f0
[  220.085233] RSP: 0018:ffff88019756e6f0 EFLAGS: 00010082
[  220.090568] RAX: 000000000000001d RBX: 0000000000000740 RCX: 0000000000000000
[  220.097821] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
[  220.105067] RBP: ffff88019756e708 R08: 0000000000000000 R09: 0000000000000001
[  220.112320] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d3b24000
[  220.119580] R13: 000000000000030e R14: 0000000000000001 R15: 000000000000030e
[  220.126837] FS:  00007f32b7f4d7c0(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
[  220.135058] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  220.140913] CR2: 00007f32b7700fb0 CR3: 000000019749c000 CR4: 00000000001406f0
[  220.148161] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  220.155407] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  220.162659] Call Trace:
[  220.165239]  kmsan_internal_unpoison_shadow+0x5c/0xe0
[  220.170412]  kmsan_unpoison_shadow+0x66/0xb0
[  220.174799]  virtqueue_get_buf_ctx+0x73f/0xa20
[  220.179369]  virtqueue_get_buf+0x72/0x90
[  220.183407]  start_xmit+0x293/0x29b0
[  220.187099]  ? packet_rcv+0x21a0/0x21a0
[  220.191050]  ? virtnet_close+0x2c0/0x2c0
[  220.195102]  dev_hard_start_xmit+0x5f1/0xc70
[  220.199491]  sch_direct_xmit+0x578/0x8f0
[  220.203529]  __qdisc_run+0x1785/0x3730
[  220.207399]  __dev_queue_xmit+0x1d50/0x3510
[  220.211701]  dev_queue_xmit+0x4b/0x60
[  220.215476]  ip_finish_output2+0x12bf/0x1490
[  220.219874]  ip_finish_output+0xcaf/0xff0
[  220.224002]  ip_output+0x505/0x5d0
[  220.227517]  ? ip_mc_finish_output+0x3b0/0x3b0
[  220.232093]  ? ip_finish_output+0xff0/0xff0
[  220.236388]  ip_queue_xmit+0x1a1d/0x1d10
[  220.240447]  ? __msan_metadata_ptr_for_store_1+0x13/0x20
[  220.245876]  ? __skb_clone+0x6ec/0x990
[  220.249742]  ? kmsan_set_origin+0x9e/0x160
[  220.253953]  ? ip_output+0x5d0/0x5d0
[  220.257649]  tcp_transmit_skb+0x3d6d/0x53b0
[  220.261951]  tcp_write_xmit+0x2d71/0xb1f0
[  220.266087]  __tcp_push_pending_frames+0x124/0x400
[  220.270993]  tcp_push+0x803/0x8f0
[  220.274424]  tcp_sendmsg_locked+0x4eb1/0x6610
[  220.278901]  tcp_sendmsg+0xb2/0x100
[  220.282502]  ? tcp_sendmsg_locked+0x6610/0x6610
[  220.287149]  inet_sendmsg+0x3f7/0x750
[  220.290925]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[  220.296263]  ? inet_getname+0x4a0/0x4a0
[  220.300212]  sock_write_iter+0x3b7/0x470
[  220.304261]  ? sock_read_iter+0x480/0x480
[  220.308387]  __vfs_write+0x7fb/0x9f0
[  220.312077]  vfs_write+0x467/0x8c0
[  220.315775]  __x64_sys_write+0x1bf/0x3e0
[  220.319813]  do_syscall_64+0x152/0x230
[  220.323678]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  220.328843] RIP: 0033:0x7f32b62e8370
[  220.332527] RSP: 002b:00007ffd9bee0b08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  220.340222] RAX: ffffffffffffffda RBX: 0000000000000138 RCX: 00007f32b62e8370
[  220.347477] RDX: 0000000000000138 RSI: 0000559c5cf9e440 RDI: 0000000000000003
[  220.354722] RBP: 0000559c5cf9e440 R08: 0000559c5cf9a8f0 R09: 0000559c5b74f820
[  220.361969] R10: 000000000aa47d83 R11: 0000000000000246 R12: 00007ffd9bee0b6c
[  220.369216] R13: 0000000000000001 R14: 0000559c5cfa44a0 R15: 0000000000000000
[  220.376463] 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 
[  220.395546] RIP: kmsan_get_shadow_address+0x1ce/0x1f0 RSP: ffff88019756e6f0
[  220.402625] ---[ end trace a906618419ed90ba ]---
[  220.407353] Kernel panic - not syncing: Fatal exception in interrupt
[  220.414305] Dumping ftrace buffer:
[  220.417838]    (ftrace buffer empty)
[  220.421522] Kernel Offset: disabled
[  220.425121] Rebooting in 86400 seconds..