[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   29.644632] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   32.914830] random: sshd: uninitialized urandom read (32 bytes read)
[   33.246586] random: sshd: uninitialized urandom read (32 bytes read)
[   34.292820] random: sshd: uninitialized urandom read (32 bytes read)
[   49.199701] random: sshd: uninitialized urandom read (32 bytes read)
[   54.631488] random: sshd: uninitialized urandom read (32 bytes read)
[   54.652449] Not allocated shadow for addr ffff8801d34b4000 (page ffffea000af3c380)
[   54.660176] Attempted to access 270 bytes
[   54.664327] ------------[ cut here ]------------
[   54.669074] kernel BUG at mm/kmsan/kmsan.c:1326!
[   54.673818] invalid opcode: 0000 [#1] SMP PTI
[   54.678377] Dumping ftrace buffer:
[   54.681889]    (ftrace buffer empty)
[   54.685660] Modules linked in:
[   54.689465] CPU: 1 PID: 4464 Comm: sshd Not tainted 4.17.0-rc3+ #90
[   54.695862] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   54.705240] RIP: 0010:kmsan_get_shadow_address+0x1ce/0x1f0
[   54.710941] RSP: 0018:ffff8801c420e700 EFLAGS: 00010082
[   54.716285] RAX: 000000000000001d RBX: 0000000000000740 RCX: 0000000000000000
[   54.723529] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
[   54.730775] RBP: ffff8801c420e718 R08: 0000000000000000 R09: 0000000000000001
[   54.738106] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d34b4000
[   54.745351] R13: 000000000000010e R14: 0000000000000001 R15: 000000000000010e
[   54.752607] FS:  00007f6631f957c0(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
[   54.760811] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   54.766973] CR2: 00007f66313e8f70 CR3: 0000000198c56000 CR4: 00000000001406e0
[   54.774225] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   54.781561] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   54.788824] Call Trace:
[   54.791400]  kmsan_internal_unpoison_shadow+0x5c/0xe0
[   54.796567]  kmsan_unpoison_shadow+0x66/0xb0
[   54.800955]  virtqueue_get_buf_ctx+0x742/0xa20
[   54.805518]  virtqueue_get_buf+0x72/0x90
[   54.809554]  start_xmit+0x293/0x29a0
[   54.813247]  ? packet_rcv+0x21a0/0x21a0
[   54.817217]  ? virtnet_close+0x2c0/0x2c0
[   54.821279]  dev_hard_start_xmit+0x5f1/0xc70
[   54.825787]  sch_direct_xmit+0x540/0x8f0
[   54.829836]  __qdisc_run+0x1785/0x3730
[   54.833708]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[   54.839061]  __dev_queue_xmit+0x1d50/0x3520
[   54.843359]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[   54.848703]  dev_queue_xmit+0x4b/0x60
[   54.852479]  ip_finish_output2+0x12a1/0x1470
[   54.857057]  ip_finish_output+0xcb2/0xff0
[   54.861193]  ip_output+0x505/0x5d0
[   54.864717]  ? ip_mc_finish_output+0x3b0/0x3b0
[   54.869306]  ? ip_finish_output+0xff0/0xff0
[   54.873619]  ip_queue_xmit+0x1a1e/0x1d10
[   54.877661]  ? __msan_metadata_ptr_for_store_1+0x13/0x20
[   54.883097]  ? __skb_clone+0x6ec/0x990
[   54.886971]  ? kmsan_set_origin+0x9e/0x160
[   54.891187]  ? ip_output+0x5d0/0x5d0
[   54.894888]  tcp_transmit_skb+0x3d81/0x53d0
[   54.899192]  tcp_write_xmit+0x2d71/0xb290
[   54.903334]  __tcp_push_pending_frames+0x124/0x3f0
[   54.908248]  tcp_push+0x8b6/0x9c0
[   54.911679]  tcp_sendmsg_locked+0x4e74/0x65a0
[   54.916158]  tcp_sendmsg+0xb2/0x100
[   54.919758]  ? tcp_sendmsg_locked+0x65a0/0x65a0
[   54.924400]  inet_sendmsg+0x48d/0x740
[   54.928185]  ? security_socket_sendmsg+0x91/0x1f0
[   54.933001]  ? inet_getname+0x4a0/0x4a0
[   54.936951]  sock_write_iter+0x3b9/0x470
[   54.940997]  ? sock_read_iter+0x480/0x480
[   54.945123]  __vfs_write+0x7fb/0x9f0
[   54.948816]  vfs_write+0x463/0x8d0
[   54.952342]  __x64_sys_write+0x1bf/0x3e0
[   54.956388]  do_syscall_64+0x154/0x220
[   54.960254]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   54.965424] RIP: 0033:0x7f6630330370
[   54.969116] RSP: 002b:00007ffd9ae891c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   54.976800] RAX: ffffffffffffffda RBX: 0000000000000138 RCX: 00007f6630330370
[   54.984134] RDX: 0000000000000138 RSI: 00005569922a0440 RDI: 0000000000000003
[   54.991376] RBP: 00005569922a0440 R08: 000055699229e4e0 R09: 0000556991802820
[   54.998627] R10: 000000003c91ab37 R11: 0000000000000246 R12: 00007ffd9ae8922c
[   55.005972] R13: 0000000000000001 R14: 00005569922a64a0 R15: 0000000000000000
[   55.013219] Code: 75 29 48 c7 c7 84 fe 9f 8a 31 c0 e8 4d 2a 83 ff 80 3c 25 f8 73 53 8b 00 75 11 48 c7 c7 b4 fe 9f 8a 31 c0 4c 89 fe e8 32 2a 83 ff <0f> 0b eb fe 48 3d ff ff ff 1f 0f 87 a2 fe ff ff 48 8b 1c 25 10 
[   55.032845] RIP: kmsan_get_shadow_address+0x1ce/0x1f0 RSP: ffff8801c420e700
[   55.039930] ---[ end trace 223e932f4a161acf ]---
[   55.044663] Kernel panic - not syncing: Fatal exception in interrupt
[   55.051559] Dumping ftrace buffer:
[   55.055080]    (ftrace buffer empty)
[   55.058766] Kernel Offset: disabled
[   55.062374] Rebooting in 86400 seconds..