[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   29.392837] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   33.663914] random: sshd: uninitialized urandom read (32 bytes read)
[   34.181302] random: sshd: uninitialized urandom read (32 bytes read)
[   35.297603] random: sshd: uninitialized urandom read (32 bytes read)
[   47.997990] random: sshd: uninitialized urandom read (32 bytes read)
[   53.518606] random: sshd: uninitialized urandom read (32 bytes read)
[   53.540630] Not allocated shadow for addr ffff8801bc1f0000 (page ffffea000a68ba00)
[   53.548362] Attempted to access 270 bytes
[   53.552543] ------------[ cut here ]------------
[   53.557275] kernel BUG at mm/kmsan/kmsan.c:1344!
[   53.562015] invalid opcode: 0000 [#1] SMP PTI
[   53.566504] Dumping ftrace buffer:
[   53.570019]    (ftrace buffer empty)
[   53.573712] Modules linked in:
[   53.576886] CPU: 0 PID: 4513 Comm: sshd Not tainted 4.17.0-rc5+ #103
[   53.583352] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   53.592696] RIP: 0010:kmsan_get_shadow_address+0x1ce/0x1f0
[   53.598295] RSP: 0018:ffff88019a64e6f0 EFLAGS: 00010082
[   53.603634] RAX: 000000000000001d RBX: 00000000000006e0 RCX: 0000000000000000
[   53.610883] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
[   53.618131] RBP: ffff88019a64e708 R08: 0000000000000000 R09: 0000000000000001
[   53.625392] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801bc1f0000
[   53.632642] R13: 000000000000010e R14: 0000000000000001 R15: 000000000000010e
[   53.639893] FS:  00007f4121cd87c0(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
[   53.648096] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   53.653957] CR2: 00007f412112bf70 CR3: 0000000199e50000 CR4: 00000000001406f0
[   53.661209] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   53.668457] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   53.675705] Call Trace:
[   53.678282]  kmsan_internal_unpoison_shadow+0x5c/0xe0
[   53.683458]  kmsan_unpoison_shadow+0x66/0xb0
[   53.687848]  virtqueue_get_buf_ctx+0x73f/0xa20
[   53.692413]  virtqueue_get_buf+0x72/0x90
[   53.696451]  start_xmit+0x293/0x29b0
[   53.700147]  ? packet_rcv+0x21a0/0x21a0
[   53.704114]  ? virtnet_close+0x2c0/0x2c0
[   53.708159]  dev_hard_start_xmit+0x5f1/0xc70
[   53.712551]  sch_direct_xmit+0x578/0x8f0
[   53.716594]  __qdisc_run+0x1785/0x3730
[   53.720466]  __dev_queue_xmit+0x1d50/0x3510
[   53.724769]  dev_queue_xmit+0x4b/0x60
[   53.728548]  ip_finish_output2+0x12bf/0x1490
[   53.732940]  ip_finish_output+0xcaf/0xff0
[   53.737075]  ip_output+0x505/0x5d0
[   53.740599]  ? ip_mc_finish_output+0x3b0/0x3b0
[   53.745163]  ? ip_finish_output+0xff0/0xff0
[   53.749464]  ip_queue_xmit+0x1a1d/0x1d10
[   53.753517]  ? __msan_metadata_ptr_for_store_1+0x13/0x20
[   53.758948]  ? __skb_clone+0x6ec/0x990
[   53.762823]  ? kmsan_set_origin+0x9e/0x160
[   53.767054]  ? ip_output+0x5d0/0x5d0
[   53.770758]  tcp_transmit_skb+0x3d6d/0x53b0
[   53.775081]  tcp_write_xmit+0x2d71/0xb1f0
[   53.779228]  __tcp_push_pending_frames+0x124/0x400
[   53.784138]  tcp_push+0x803/0x8f0
[   53.787572]  tcp_sendmsg_locked+0x4eb1/0x6610
[   53.792058]  tcp_sendmsg+0xb2/0x100
[   53.795663]  ? tcp_sendmsg_locked+0x6610/0x6610
[   53.800312]  inet_sendmsg+0x3f7/0x750
[   53.804093]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[   53.809436]  ? inet_getname+0x4a0/0x4a0
[   53.813388]  sock_write_iter+0x3b7/0x470
[   53.817428]  ? sock_read_iter+0x480/0x480
[   53.821554]  __vfs_write+0x7fb/0x9f0
[   53.825247]  vfs_write+0x467/0x8c0
[   53.828768]  __x64_sys_write+0x1bf/0x3e0
[   53.832810]  do_syscall_64+0x152/0x230
[   53.836680]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   53.841847] RIP: 0033:0x7f4120073370
[   53.845557] RSP: 002b:00007ffe03fb1d58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   53.853243] RAX: ffffffffffffffda RBX: 0000000000000138 RCX: 00007f4120073370
[   53.860491] RDX: 0000000000000138 RSI: 00005580bbd21440 RDI: 0000000000000003
[   53.867740] RBP: 00005580bbd21440 R08: 00005580bbd1f590 R09: 00005580ba392820
[   53.874989] R10: 0000000041477289 R11: 0000000000000246 R12: 00007ffe03fb1dbc
[   53.882241] R13: 0000000000000001 R14: 00005580bbd274a0 R15: 0000000000000000
[   53.889493] 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 
[   53.908584] RIP: kmsan_get_shadow_address+0x1ce/0x1f0 RSP: ffff88019a64e6f0
[   53.915666] ---[ end trace 466331df613180d7 ]---
[   53.920398] Kernel panic - not syncing: Fatal exception in interrupt
[   53.927380] Dumping ftrace buffer:
[   53.930910]    (ftrace buffer empty)
[   53.934596] Kernel Offset: disabled
[   53.938211] Rebooting in 86400 seconds..