[ 16.424020] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.125844] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.479517] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.215067] random: sshd: uninitialized urandom read (32 bytes read, 83 bits of entropy available) [ 22.387171] random: sshd: uninitialized urandom read (32 bytes read, 87 bits of entropy available) Warning: Permanently added '10.128.0.47' (ECDSA) to the list of known hosts. [ 27.782955] random: sshd: uninitialized urandom read (32 bytes read, 95 bits of entropy available) executing program [ 27.875151] kasan: CONFIG_KASAN_INLINE enabled [ 27.880079] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN [ 27.892875] Dumping ftrace buffer: [ 27.896379] (ftrace buffer empty) [ 27.900064] Modules linked in: [ 27.903335] CPU: 1 PID: 3311 Comm: syzkaller717382 Not tainted 4.4.107-g610c835 #4 [ 27.911022] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.920344] task: ffff8800b57caf80 task.stack: ffff8801d5798000 [ 27.926365] RIP: 0010:[] [] __free_pages+0x21/0x90 [ 27.934593] RSP: 0018:ffff8801d579fa40 EFLAGS: 00010a07 [ 27.940006] RAX: dffffc0000000000 RBX: dead4ead00000000 RCX: ffffffff825b8ccb [ 27.947252] RDX: 1bd5a9d5a0000003 RSI: 0000000000000001 RDI: dead4ead0000001c [ 27.954488] RBP: ffff8801d579fa50 R08: 0000000000000001 R09: 0000000000000000 [ 27.961725] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000004 [ 27.968961] R13: 0000000000000020 R14: ffff8801d5500000 R15: dffffc0000000000 [ 27.976199] FS: 0000000000000000(0000) GS:ffff8801db300000(0063) knlGS:0000000009cab840 [ 27.984389] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 27.990236] CR2: 000000002068cfc0 CR3: 00000001d50a4000 CR4: 00000000001406e0 [ 27.997483] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 28.004719] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 28.011956] Stack: [ 28.014069] 0000000000000000 ffff8801d5500158 ffff8801d579fab0 ffffffff825b8cf1 [ 28.022014] ffff8801d5500170 ffffed003aaa002b ffffed003aaa002e ffff8801d5500168 [ 28.029963] dead4ead00000000 ffff8801d5500140 0000000000000000 0000000000000000 [ 28.037916] Call Trace: [ 28.040472] [] sg_remove_scat.isra.17+0x1c1/0x2d0 [ 28.046939] [] sg_finish_rem_req+0x2b5/0x340 [ 28.052964] [] sg_new_read.isra.18+0x39/0x3c0 [ 28.059074] [] ? sg_get_rq_mark+0x142/0x190 [ 28.065018] [] sg_read+0x8c2/0x1490 [ 28.070269] [] ? __alloc_pages_direct_compact+0x250/0x250 [ 28.077426] [] ? sg_proc_seq_show_debug+0xd30/0xd30 [ 28.084059] [] ? __lock_is_held+0xa1/0xf0 [ 28.089833] [] ? sg_proc_seq_show_debug+0xd30/0xd30 [ 28.096472] [] __vfs_read+0x103/0x440 [ 28.101895] [] ? vfs_iter_write+0x2d0/0x2d0 [ 28.107842] [] ? fsnotify+0x5ad/0xee0 [ 28.113259] [] ? fsnotify+0xee0/0xee0 [ 28.118674] [] ? _raw_spin_unlock+0x2c/0x50 [ 28.124614] [] ? avc_policy_seqno+0x9/0x20 [ 28.130467] [] ? selinux_file_permission+0x348/0x460 [ 28.137187] [] ? security_file_permission+0x89/0x1e0 [ 28.143907] [] ? rw_verify_area+0x100/0x2f0 [ 28.149846] [] vfs_read+0x123/0x3a0 [ 28.155098] [] SyS_read+0xd9/0x1b0 [ 28.160254] [] ? do_sendfile+0xd30/0xd30 [ 28.165932] [] ? do_fast_syscall_32+0xd7/0x890 [ 28.172127] [] ? do_sendfile+0xd30/0xd30 [ 28.177807] [] do_fast_syscall_32+0x314/0x890 [ 28.183918] [] sysenter_flags_fixed+0xd/0x17 [ 28.189943] Code: 76 ae 0c 00 e9 78 fd ff ff 90 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 53 48 89 fb 48 83 c7 1c 48 89 fa 48 83 ec 08 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 49 [ 28.216330] RIP [] __free_pages+0x21/0x90 [ 28.222214] RSP [ 28.229887] ---[ end trace 081839b3b20b407b ]--- [ 28.234628] Kernel panic - not syncing: Fatal exception [ 28.240414] Dumping ftrace buffer: [ 28.243919] (ftrace buffer empty) [ 28.247595] Kernel Offset: disabled [ 28.251188] Rebooting in 86400 seconds..