[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   33.357179] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   37.732967] random: sshd: uninitialized urandom read (32 bytes read)
[   38.230491] random: sshd: uninitialized urandom read (32 bytes read)
[   39.483480] random: sshd: uninitialized urandom read (32 bytes read)
[ 1087.899113] random: sshd: uninitialized urandom read (32 bytes read)
[ 1093.313383] random: sshd: uninitialized urandom read (32 bytes read)
[ 1093.335615] Not allocated shadow for addr ffff8801d39e8000 (page ffffea000af5b700)
[ 1093.343353] Attempted to access 782 bytes
[ 1093.347505] ------------[ cut here ]------------
[ 1093.352237] kernel BUG at mm/kmsan/kmsan.c:1326!
[ 1093.356979] invalid opcode: 0000 [#1] SMP PTI
[ 1093.361448] Dumping ftrace buffer:
[ 1093.364959]    (ftrace buffer empty)
[ 1093.368656] Modules linked in:
[ 1093.371828] CPU: 1 PID: 4523 Comm: sshd Not tainted 4.17.0-rc3+ #88
[ 1093.378204] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 1093.387544] RIP: 0010:kmsan_get_shadow_address+0x1ce/0x1f0
[ 1093.393140] RSP: 0018:ffff8801ce4ae700 EFLAGS: 00010082
[ 1093.398482] RAX: 000000000000001d RBX: 0000000000000740 RCX: 0000000000000000
[ 1093.405725] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
[ 1093.412967] RBP: ffff8801ce4ae718 R08: 0000000000000000 R09: 0000000000000001
[ 1093.420212] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d39e8000
[ 1093.427453] R13: 000000000000030e R14: 0000000000000001 R15: 000000000000030e
[ 1093.434698] FS:  00007fa09effd7c0(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
[ 1093.442896] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1093.448760] CR2: 00007fa09e7b0fb0 CR3: 00000001cb508000 CR4: 00000000001406e0
[ 1093.456016] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1093.463262] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1093.470505] Call Trace:
[ 1093.473069]  kmsan_internal_unpoison_shadow+0x5c/0xe0
[ 1093.478232]  kmsan_unpoison_shadow+0x66/0xb0
[ 1093.482627]  virtqueue_get_buf_ctx+0x742/0xa20
[ 1093.487188]  virtqueue_get_buf+0x72/0x90
[ 1093.491224]  start_xmit+0x293/0x29a0
[ 1093.494915]  ? packet_rcv+0x21a0/0x21a0
[ 1093.498865]  ? virtnet_close+0x2c0/0x2c0
[ 1093.502900]  dev_hard_start_xmit+0x5f1/0xc70
[ 1093.507286]  sch_direct_xmit+0x540/0x8f0
[ 1093.511322]  __qdisc_run+0x1785/0x3730
[ 1093.515187]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[ 1093.520528]  __dev_queue_xmit+0x1d50/0x3520
[ 1093.524825]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[ 1093.530167]  dev_queue_xmit+0x4b/0x60
[ 1093.533943]  ip_finish_output2+0x12a1/0x1470
[ 1093.538336]  ip_finish_output+0xcb2/0xff0
[ 1093.542461]  ip_output+0x505/0x5d0
[ 1093.545977]  ? ip_mc_finish_output+0x3b0/0x3b0
[ 1093.550534]  ? ip_finish_output+0xff0/0xff0
[ 1093.554829]  ip_queue_xmit+0x1a1e/0x1d10
[ 1093.558867]  ? __msan_metadata_ptr_for_store_1+0x13/0x20
[ 1093.564292]  ? __skb_clone+0x6ec/0x990
[ 1093.568159]  ? kmsan_set_origin+0x9e/0x160
[ 1093.572368]  ? ip_output+0x5d0/0x5d0
[ 1093.576066]  tcp_transmit_skb+0x3d81/0x53d0
[ 1093.580368]  tcp_write_xmit+0x2d71/0xb290
[ 1093.584503]  __tcp_push_pending_frames+0x124/0x3f0
[ 1093.589408]  tcp_push+0x8b6/0x9c0
[ 1093.592839]  tcp_sendmsg_locked+0x4e74/0x65a0
[ 1093.597319]  tcp_sendmsg+0xb2/0x100
[ 1093.600921]  ? tcp_sendmsg_locked+0x65a0/0x65a0
[ 1093.605565]  inet_sendmsg+0x48d/0x740
[ 1093.609340]  ? security_socket_sendmsg+0x91/0x1f0
[ 1093.614159]  ? inet_getname+0x4a0/0x4a0
[ 1093.618114]  sock_write_iter+0x3b9/0x470
[ 1093.622155]  ? sock_read_iter+0x480/0x480
[ 1093.626276]  __vfs_write+0x7fb/0x9f0
[ 1093.629966]  vfs_write+0x463/0x8d0
[ 1093.633482]  __x64_sys_write+0x1bf/0x3e0
[ 1093.637521]  do_syscall_64+0x154/0x220
[ 1093.641388]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1093.646550] RIP: 0033:0x7fa09d398370
[ 1093.650233] RSP: 002b:00007ffe3a0a0b78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 1093.657924] RAX: ffffffffffffffda RBX: 0000000000000138 RCX: 00007fa09d398370
[ 1093.665167] RDX: 0000000000000138 RSI: 000055db9e579440 RDI: 0000000000000003
[ 1093.672413] RBP: 000055db9e579440 R08: 000055db9e5758f0 R09: 000055db9ca91820
[ 1093.679657] R10: 00000000c7c1e4e4 R11: 0000000000000246 R12: 00007ffe3a0a0bdc
[ 1093.686900] R13: 0000000000000001 R14: 000055db9e57f4a0 R15: 0000000000000000
[ 1093.694145] 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 
[ 1093.713220] RIP: kmsan_get_shadow_address+0x1ce/0x1f0 RSP: ffff8801ce4ae700
[ 1093.720295] ---[ end trace 640b18cd036ab56d ]---
[ 1093.725370] Kernel panic - not syncing: Fatal exception in interrupt
[ 1093.732250] Dumping ftrace buffer:
[ 1093.735773]    (ftrace buffer empty)
[ 1093.739458] Kernel Offset: disabled
[ 1093.743059] Rebooting in 86400 seconds..