Starting mcstransd: [ 20.019164] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.507087] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [ 21.828201] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [ 22.806687] random: nonblocking pool is initialized Warning: Permanently added '10.128.0.51' (ECDSA) to the list of known hosts. executing program [ 28.542014] ================================================================== [ 28.549486] BUG: KASAN: use-after-free in ip6_xmit+0x1a2c/0x1a70 [ 28.555600] Read of size 8 at addr ffff8801d49d1658 by task syzkaller677477/3741 [ 28.563099] [ 28.564709] CPU: 0 PID: 3741 Comm: syzkaller677477 Not tainted 4.4.120-gd63fdf6 #28 [ 28.572468] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.581791] 0000000000000000 997781c320663151 ffff8801cacb76a8 ffffffff81d0408d [ 28.589754] ffffea0007527440 ffff8801d49d1658 0000000000000000 ffff8801d49d1658 [ 28.597716] 0000000000000040 ffff8801cacb76e0 ffffffff814fe143 ffff8801d49d1658 [ 28.605682] Call Trace: [ 28.608239] [] dump_stack+0xc1/0x124 [ 28.613570] [] print_address_description+0x73/0x260 [ 28.620201] [] kasan_report+0x285/0x370 [ 28.625794] [] ? ip6_xmit+0x1a2c/0x1a70 [ 28.631388] [] __asan_report_load8_noabort+0x14/0x20 [ 28.638529] [] ip6_xmit+0x1a2c/0x1a70 [ 28.643949] [] ? kfree+0xfc/0x300 [ 28.649021] [] ? pskb_expand_head+0x28b/0x980 [ 28.655136] [] ? l2tp_xmit_skb+0xa5e/0xea0 [ 28.660990] [] ? ip6_finish_output2+0x1c60/0x1c60 [ 28.667449] [] ? __lock_is_held+0xa1/0xf0 [ 28.673215] [] ? ipv4_dst_check+0x111/0x160 [ 28.679153] [] ? __sk_dst_check+0x148/0x260 [ 28.685700] [] inet6_csk_xmit+0x246/0x480 [ 28.691465] [] ? inet6_csk_xmit+0x100/0x480 [ 28.697402] [] ? inet6_csk_update_pmtu+0x160/0x160 [ 28.703951] [] ? udp6_set_csum+0x336/0xa80 [ 28.709801] [] l2tp_xmit_skb+0xc2f/0xea0 [ 28.715481] [] pppol2tp_sendmsg+0x584/0x7f0 [ 28.721422] [] ? selinux_socket_sendmsg+0x3f/0x50 [ 28.727881] [] ? pppol2tp_release+0x310/0x310 [ 28.733993] [] sock_sendmsg+0xca/0x110 [ 28.739498] [] ___sys_sendmsg+0x6c1/0x7c0 [ 28.745263] [] ? copy_msghdr_from_user+0x550/0x550 [ 28.751813] [] ? check_preemption_disabled+0x3b/0x200 [ 28.758620] [] ? do_huge_pmd_anonymous_page+0x549/0xa10 [ 28.765599] [] ? _raw_spin_unlock+0x2c/0x50 [ 28.771539] [] ? do_huge_pmd_anonymous_page+0x3dd/0xa10 [ 28.778520] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 28.785238] [] ? __fget_light+0xa3/0x1e0 [ 28.790917] [] ? __fdget+0x18/0x20 [ 28.796073] [] __sys_sendmsg+0xd3/0x190 [ 28.801664] [] ? SyS_shutdown+0x1b0/0x1b0 [ 28.807428] [] ? __do_page_fault+0x380/0xa00 [ 28.813456] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 28.820262] [] SyS_sendmsg+0x2d/0x50 [ 28.825594] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 28.832136] [ 28.833732] Allocated by task 3739: [ 28.837323] [] save_stack_trace+0x26/0x50 [ 28.843209] [] save_stack+0x43/0xd0 [ 28.849185] [] kasan_kmalloc+0xad/0xe0 [ 28.854803] [] kasan_slab_alloc+0x12/0x20 [ 28.860679] [] kmem_cache_alloc+0xba/0x290 [ 28.866664] [] dst_alloc+0x11f/0x1a0 [ 28.872119] [] rt_dst_alloc+0x78/0x430 [ 28.877746] [] __ip_route_output_key_hash+0xa4e/0x2390 [ 28.884761] [] __ip4_datagram_connect+0xa15/0x1150 [ 28.891424] [] __ip6_datagram_connect+0x4d9/0x1950 [ 28.898093] [] ip6_datagram_connect+0x2f/0x50 [ 28.904321] [] inet_dgram_connect+0x16b/0x1f0 [ 28.910550] [] SYSC_connect+0x1b6/0x310 [ 28.916257] [] SyS_connect+0x24/0x30 [ 28.921703] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 28.928366] [ 28.929961] Freed by task 0: [ 28.932945] [] save_stack_trace+0x26/0x50 [ 28.938828] [] save_stack+0x43/0xd0 [ 28.944188] [] kasan_slab_free+0x72/0xc0 [ 28.949981] [] kmem_cache_free+0xc7/0x320 [ 28.955861] [] dst_destroy+0x20e/0x330 [ 28.961479] [] dst_destroy_rcu+0x15/0x40 [ 28.967272] [] rcu_process_callbacks+0x7f4/0x14a0 [ 28.973847] [] __do_softirq+0x227/0xa38 [ 28.979570] [ 28.981169] The buggy address belongs to the object at ffff8801d49d1640 [ 28.981169] which belongs to the cache ip_dst_cache of size 208 [ 28.993880] The buggy address is located 24 bytes inside of [ 28.993880] 208-byte region [ffff8801d49d1640, ffff8801d49d1710) [ 29.005633] The buggy address belongs to the page: [ 29.020804] kasan: CONFIG_KASAN_INLINE enabled [ 29.025212] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN [ 29.038133] Dumping ftrace buffer: [ 29.041658] (ftrace buffer empty) [ 29.045352] Modules linked in: [ 29.048662] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.120-gd63fdf6 #28 [ 29.055656] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.064994] task: ffff8801d9b49800 task.stack: ffff8801d9b58000 [ 29.071036] RIP: 0010:[] [] rb_insert_color+0x7b/0xcb0 [ 29.079650] RSP: 0018:ffff8801db307d18 EFLAGS: 00010002 [ 29.085080] RAX: 0000000000000008 RBX: 0000000000000000 RCX: 0000000000000000 [ 29.092333] RDX: 0000000000000001 RSI: ffff8801db319710 RDI: ffff8801db319c40 [ 29.099588] RBP: ffff8801db307d60 R08: ffffffff857d3748 R09: 0000000000000001 [ 29.106844] R10: 0000000000000000 R11: 1ffff1003b660f62 R12: ffff8801c8667df8 [ 29.114098] R13: 0000000000000000 R14: ffff8801db319c40 R15: dffffc0000000000 [ 29.121353] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.129566] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.135433] CR2: 0000562055ddb110 CR3: 00000001d9880000 CR4: 0000000000160670 [ 29.142693] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.149957] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.157223] Stack: [ 29.159380] ffffffff842bdb60 ffff8801d9b4a0d0 0000000000000000 ffff8801db307d70 [ 29.167428] ffff8801db319c40 dffffc0000000000 0000000000000000 ffff8801db319710 [ 29.175486] ffff8801c8667e00 ffff8801db307db0 ffffffff81d21967 ffff8801db319c58 [ 29.183525] Call Trace: [ 29.186093] [ 29.188152] [] timerqueue_add+0x157/0x2a0 [ 29.194244] [] enqueue_hrtimer+0x168/0x450 [ 29.200124] [] __hrtimer_run_queues+0x732/0xfe0 [ 29.206435] [] ? hrtimer_fixup_init+0x70/0x70 [ 29.212572] [] ? hrtimer_interrupt+0x131/0x440 [ 29.218796] [] hrtimer_interrupt+0x1a6/0x440 [ 29.224846] [] local_apic_timer_interrupt+0x6a/0xb0 [ 29.231504] [] smp_apic_timer_interrupt+0x76/0xa0 [ 29.237983] [] apic_timer_interrupt+0xa0/0xb0 [ 29.244107] [ 29.246161] [] ? native_safe_halt+0x6/0x10 [ 29.252337] [] ? trace_hardirqs_on+0xd/0x10 [ 29.258297] [] default_idle+0x55/0x3c0 [ 29.263825] [] arch_cpu_idle+0xa/0x10 [ 29.269262] [] default_idle_call+0x48/0x70 [ 29.275135] [] cpu_startup_entry+0x5fd/0x8f0 [ 29.281186] [] ? call_cpuidle+0xe0/0xe0 [ 29.286799] [] ? clockevents_register_device+0x122/0x230 [ 29.293884] [] start_secondary+0x304/0x3e0 [ 29.299756] [] ? set_cpu_sibling_map+0x1080/0x1080 [ 29.306318] Code: 0f 85 06 0a 00 00 49 bf 00 00 00 00 00 fc ff df 49 8b 1c 24 f6 c3 01 0f 85 9a 01 00 00 48 8d 43 08 48 89 d9 48 89 c2 48 c1 ea 03 <42> 80 3c 3a 00 0f 85 94 09 00 00 4c 8b 6b 08 4d 39 e5 0f 84 b0 [ 29.333842] RIP [] rb_insert_color+0x7b/0xcb0 [ 29.340118] RSP [ 29.343733] ---[ end trace eb7d2fc07caffc51 ]--- [ 29.348474] Kernel panic - not syncing: Fatal exception in interrupt [ 30.465808] Shutting down cpus with NMI [ 30.470712] Dumping ftrace buffer: [ 30.474229] (ftrace buffer empty) [ 30.477917] Kernel Offset: disabled [ 30.481512] Rebooting in 86400 seconds..