[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.792040] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.234638] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.559150] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 22.518943] random: sshd: uninitialized urandom read (32 bytes read, 112 bits of entropy available) [ 22.684621] random: sshd: uninitialized urandom read (32 bytes read, 116 bits of entropy available) Warning: Permanently added '10.128.15.194' (ECDSA) to the list of known hosts. [ 28.070972] random: sshd: uninitialized urandom read (32 bytes read, 124 bits of entropy available) executing program [ 28.167326] ================================================================== [ 28.174721] BUG: KASAN: use-after-free in ip6_xmit+0x193a/0x1ad0 [ 28.180836] Read of size 8 at addr ffff8801d4255518 by task syzkaller271047/3323 [ 28.188336] [ 28.189934] CPU: 0 PID: 3323 Comm: syzkaller271047 Not tainted 4.4.113-gef588ef #26 [ 28.197704] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.207029] 0000000000000000 2f3c8bc7595f5d61 ffff8801d024f768 ffffffff81d0278d [ 28.214994] ffffea0007509540 ffff8801d4255518 0000000000000000 ffff8801d4255518 [ 28.222965] 0000000000000040 ffff8801d024f7a0 ffffffff814fd053 ffff8801d4255518 [ 28.230932] Call Trace: [ 28.233490] [] dump_stack+0xc1/0x124 [ 28.238823] [] print_address_description+0x73/0x260 [ 28.245471] [] kasan_report+0x285/0x370 [ 28.251075] [] ? ip6_xmit+0x193a/0x1ad0 [ 28.256669] [] __asan_report_load8_noabort+0x14/0x20 [ 28.263392] [] ip6_xmit+0x193a/0x1ad0 [ 28.268810] [] ? kfree+0xfc/0x300 [ 28.273883] [] ? pskb_expand_head+0x28b/0x980 [ 28.280000] [] ? l2tp_xmit_skb+0xa5e/0xea0 [ 28.285853] [] ? ip6_finish_output2+0x1c60/0x1c60 [ 28.292315] [] ? __lock_is_held+0xa1/0xf0 [ 28.298086] [] ? ipv4_dst_check+0x111/0x160 [ 28.304027] [] ? __sk_dst_check+0x148/0x260 [ 28.309969] [] inet6_csk_xmit+0x246/0x480 [ 28.315736] [] ? inet6_csk_xmit+0x100/0x480 [ 28.321684] [] ? inet6_csk_update_pmtu+0x160/0x160 [ 28.328231] [] ? udp6_set_csum+0x336/0xa80 [ 28.334086] [] l2tp_xmit_skb+0xc2f/0xea0 [ 28.339765] [] pppol2tp_sendmsg+0x584/0x7f0 [ 28.345707] [] ? selinux_socket_sendmsg+0x3f/0x50 [ 28.352168] [] ? pppol2tp_release+0x310/0x310 [ 28.358286] [] sock_sendmsg+0xca/0x110 [ 28.363791] [] SYSC_sendto+0x2c8/0x340 [ 28.369301] [] ? SYSC_connect+0x310/0x310 [ 28.375072] [] ? do_huge_pmd_anonymous_page+0x549/0xa10 [ 28.382057] [] ? _raw_spin_unlock+0x2c/0x50 [ 28.388000] [] SyS_sendto+0x40/0x50 [ 28.393246] [] ? SyS_getpeername+0x30/0x30 [ 28.399102] [] do_fast_syscall_32+0x314/0x890 [ 28.405217] [] sysenter_flags_fixed+0xd/0x17 [ 28.411239] [ 28.412835] Allocated by task 3304: [ 28.416429] [] save_stack_trace+0x26/0x50 [ 28.422314] [] save_stack+0x43/0xd0 [ 28.427678] [] kasan_kmalloc+0xad/0xe0 [ 28.433302] [] kasan_slab_alloc+0x12/0x20 [ 28.439185] [] kmem_cache_alloc+0xba/0x290 [ 28.445156] [] dst_alloc+0x11f/0x1a0 [ 28.450606] [] rt_dst_alloc+0x78/0x430 [ 28.456229] [] __ip_route_output_key_hash+0xa4e/0x2390 [ 28.463244] [] __ip4_datagram_connect+0xa15/0x1150 [ 28.469909] [] __ip6_datagram_connect+0x4d9/0x1950 [ 28.476583] [] ip6_datagram_connect+0x2f/0x50 [ 28.482809] [] inet_dgram_connect+0x16b/0x1f0 [ 28.489036] [] SYSC_connect+0x1b6/0x310 [ 28.494747] [] SyS_connect+0x24/0x30 [ 28.500197] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 28.506859] [ 28.508455] Freed by task 0: [ 28.511441] [] save_stack_trace+0x26/0x50 [ 28.517325] [] save_stack+0x43/0xd0 [ 28.522690] [] kasan_slab_free+0x72/0xc0 [ 28.528486] [] kmem_cache_free+0xc7/0x320 [ 28.534371] [] dst_destroy+0x20e/0x330 [ 28.540000] [] dst_destroy_rcu+0x15/0x40 [ 28.545798] [] rcu_process_callbacks+0x7f4/0x14a0 [ 28.552380] [] __do_softirq+0x227/0xa38 [ 28.558103] [ 28.559701] The buggy address belongs to the object at ffff8801d4255500 [ 28.559701] which belongs to the cache ip_dst_cache of size 208 [ 28.572413] The buggy address is located 24 bytes inside of [ 28.572413] 208-byte region [ffff8801d4255500, ffff8801d42555d0) [ 28.584167] The buggy address belongs to the page: [ 29.215656] kasan: CONFIG_KASAN_INLINE enabled [ 29.220107] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN [ 29.233112] Dumping ftrace buffer: [ 29.236642] (ftrace buffer empty) [ 29.240339] Modules linked in: [ 29.243662] CPU: 1 PID: 3324 Comm: modprobe Not tainted 4.4.113-gef588ef #26 [ 29.250836] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.260192] task: ffff8801d04297c0 task.stack: ffff8801d0018000 [ 29.266246] RIP: 0010:[] [] __list_del_entry+0x86/0x1d0 [ 29.274971] RSP: 0018:ffff8801d001fcc8 EFLAGS: 00010246 [ 29.280424] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff8801ccc485e0 [ 29.287689] RDX: 0000000000000000 RSI: 0000000000000028 RDI: ffff8801ccc485e8 [ 29.294955] RBP: ffff8801d001fce0 R08: 0000000000000001 R09: ffffffff838591e0 [ 29.302220] R10: 0000000000000001 R11: 1ffff1003a003f66 R12: ffffea0007509540 [ 29.309507] R13: ffff8801ccc48618 R14: ffffffff8156c940 R15: ffff8801ccc484a0 [ 29.316777] FS: 00007fb14d223700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.324996] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.330881] CR2: 00007fb14d228000 CR3: 00000001d008c000 CR4: 0000000000160670 [ 29.338176] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.345449] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.352711] Stack: [ 29.354855] ffffffff83770cce ffff8801ccc485e0 ffff8801da26c240 ffff8801d001fd00 [ 29.362916] ffffffff8148e22a ffff8801ccc48458 ffff8801ccc485e0 ffff8801d001fd60 [ 29.370972] ffffffff81571160 ffff8801d04297c0 ffff8801ccc48480 ffffffff838c8820 [ 29.379036] Call Trace: [ 29.381614] [] ? _raw_spin_lock+0x3e/0x50 [ 29.387419] [] list_lru_del+0x6a/0x170 [ 29.392953] [] iput+0x480/0x960 [ 29.397882] [] __dentry_kill+0x51c/0x620 [ 29.403598] [] ? dput.part.19+0x2a/0x760 [ 29.409313] [] dput.part.19+0x4c1/0x760 [ 29.414941] [] ? dput.part.19+0x2a/0x760 [ 29.420659] [] ? close_pdeo+0x230/0x230 [ 29.426292] [] dput+0x1f/0x30 [ 29.431055] [] __fput+0x411/0x6d0 [ 29.436162] [] ____fput+0x15/0x20 [ 29.441271] [] task_work_run+0x104/0x180 [ 29.446988] [] exit_to_usermode_loop+0x13d/0x160 [ 29.453410] [] syscall_return_slowpath+0x1b5/0x1f0 [ 29.459990] [] int_ret_from_sys_call+0x25/0xa3 [ 29.466211] Code: c4 0f 84 94 00 00 00 48 b8 00 02 00 00 00 00 ad de 48 39 c3 0f 84 a5 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 e8 00 00 00 4c 8b 03 49 39 c8 0f 85 9b 00 00 [ 29.493790] RIP [] __list_del_entry+0x86/0x1d0 [ 29.500157] RSP [ 29.503817] BUG: unable to handle kernel paging request at fffffffb8ec67c08 [ 29.511171] IP: [] cpuacct_charge+0x155/0x390 [ 29.517363] PGD 420f067 PUD 0 [ 29.520816] Oops: 0000 [#2] PREEMPT SMP KASAN [ 29.525818] Dumping ftrace buffer: [ 29.529350] (ftrace buffer empty) [ 29.533052] Modules linked in: [ 29.536371] CPU: 1 PID: 3324 Comm: modprobe Tainted: G D 4.4.113-gef588ef #26 [ 29.544766] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.554123] task: ffff8801d04297c0 task.stack: ffff8801d0018000 [ 29.560179] RIP: 0010:[] [] cpuacct_charge+0x155/0x390 [ 29.568823] RSP: 0018:ffff8801db307a20 EFLAGS: 00010046 [ 29.574270] RAX: 1ffffffff0854fff RBX: 0000000000018528 RCX: ffffffff847eb500 [ 29.581535] RDX: fffffbff71d8cf81 RSI: fffffffb8ec67c08 RDI: ffffffff842a7ff8 [ 29.588801] RBP: ffff8801db307a68 R08: 0000000000000000 R09: 0000000000000001 [ 29.596070] R10: ffffffff83844340 R11: 1ffff1003b660f10 R12: ffffffff842a7f20 [ 29.603342] R13: dffffc0000000000 R14: 000000004fa9a8c2 R15: ffffffff8148f8e1 [ 29.610610] FS: 00007fb14d223700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.618832] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.624717] CR2: fffffffb8ec67c08 CR3: 00000001d008c000 CR4: 0000000000160670 [ 29.631994] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.639261] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.647532] Stack: [ 29.649674] ffffffff8122a430 0000000000000046 ffff8801db307a70 ffffffff81d6253b [ 29.657730] ffff8801d0428060 ffffffff83844340 000000004fa9a8c2 ffff8801d04280b0 [ 29.665775] ffff8801d0428000 ffff8801db307ab8 ffffffff811dbea7 ffff8801db21f4c0 [ 29.673831] Call Trace: [ 29.676406] [ 29.678462] [] ? cpuacct_charge+0x60/0x390 [ 29.684645] [] ? check_preemption_disabled+0x3b/0x200 [ 29.691490] [] update_curr+0x2c7/0x6c0 [ 29.697032] [] enqueue_task_fair+0x313/0x2940 [ 29.703184] [] ? sched_clock_cpu+0x15f/0x1e0 [ 29.709243] [] activate_task+0x148/0x270 [ 29.714962] [] ttwu_do_activate.constprop.131+0xbf/0x1e0 [ 29.722072] [] try_to_wake_up+0x68d/0xf60 [ 29.727883] [] default_wake_function+0x35/0x50 [ 29.734120] [] autoremove_wake_function+0x13/0x90 [ 29.740615] [] ? check_preemption_disabled+0x3b/0x200 [ 29.747462] [] __wake_up_common+0xb4/0x150 [ 29.753352] [] __wake_up+0x34/0x50 [ 29.758550] [] wake_up_klogd_work_func+0x56/0x80 [ 29.764959] [] irq_work_run_list+0xca/0x140 [ 29.770939] [] irq_work_tick+0x10e/0x170 [ 29.776654] [] update_process_times+0x52/0x70 [ 29.782807] [] tick_sched_handle.isra.16+0x55/0xf0 [ 29.789396] [] tick_sched_timer+0x72/0x120 [ 29.795281] [] ? tick_sched_do_timer+0xa0/0xa0 [ 29.801521] [] __hrtimer_run_queues+0x306/0xfe0 [ 29.807854] [] ? hrtimer_fixup_init+0x70/0x70 [ 29.814010] [] ? hrtimer_interrupt+0x131/0x440 [ 29.820252] [] hrtimer_interrupt+0x1a6/0x440 [ 29.826318] [] local_apic_timer_interrupt+0x6a/0xb0 [ 29.832982] [] smp_apic_timer_interrupt+0x76/0xa0 [ 29.839483] [] apic_timer_interrupt+0xa0/0xb0 [ 29.845622] [ 29.847686] [] ? add_taint+0x1c/0x50 [ 29.853354] [] ? oops_end+0x64/0xc0 [ 29.858638] [] die+0x46/0x60 [ 29.863310] [] ? find_inode_nowait+0x180/0x180 [ 29.869549] [] do_general_protection+0x314/0x390 [ 29.875959] [] ? find_inode_nowait+0x180/0x180 [ 29.882195] [] general_protection+0x28/0x30 [ 29.888170] [] ? find_inode_nowait+0x180/0x180 [ 29.894419] [] ? __list_del_entry+0x86/0x1d0 [ 29.900481] [] ? _raw_spin_lock+0x3e/0x50 [ 29.906297] [] list_lru_del+0x6a/0x170 [ 29.911840] [] iput+0x480/0x960 [ 29.916775] [] __dentry_kill+0x51c/0x620 [ 29.922497] [] ? dput.part.19+0x2a/0x760 [ 29.928214] [] dput.part.19+0x4c1/0x760 [ 29.933851] [] ? dput.part.19+0x2a/0x760 [ 29.939569] [] ? close_pdeo+0x230/0x230 [ 29.945199] [] dput+0x1f/0x30 [ 29.949961] [] __fput+0x411/0x6d0 [ 29.955095] [] ____fput+0x15/0x20 [ 29.960206] [] task_work_run+0x104/0x180 [ 29.965916] [] exit_to_usermode_loop+0x13d/0x160 [ 29.972326] [] syscall_return_slowpath+0x1b5/0x1f0 [ 29.978922] [] int_ret_from_sys_call+0x25/0xa3 [ 29.985151] Code: 49 8d bc 24 d8 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f 85 9e 01 00 00 49 8b 9c 24 d8 00 00 00 80 3a 00 0f 85 0a 02 00 00 <4a> 03 1c f9 48 89 d8 48 c1 e8 03 42 80 3c 28 00 0f 85 cf 01 00 [ 30.012855] RIP [] cpuacct_charge+0x155/0x390 [ 30.019134] RSP [ 30.023358] CR2: fffffffb8ec67c08 [ 30.026798] ---[ end trace 034309c6c96f4886 ]--- [ 30.031544] Kernel panic - not syncing: Fatal exception in interrupt [ 30.270118] PANIC: double fault, error_code: 0x0 [ 30.274902] CPU: 0 PID: 3323 Comm: syzkaller271047 Tainted: G D 4.4.113-gef588ef #26 [ 30.283895] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.293221] task: ffff8801d0428000 task.stack: ffff8801d0248000 [ 30.299249] RIP: 0010:[] [] dump_page_badflags+0x6/0x250 [ 30.308013] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 30.313434] RAX: ffff8801d0428000 RBX: ffffea0007509540 RCX: ffffffff8148f8d0 [ 30.320677] RDX: 0000000000000000 RSI: ffffffff838a8de0 RDI: ffffea0007509540 [ 30.327922] RBP: ffff880100000008 R08: 0000000000000001 R09: 0000000000000000 [ 30.335179] R10: 0000000000000002 R11: fffffbfff0ad7e26 R12: 0000000000000000 [ 30.342426] R13: ffffffff838a8de0 R14: 0000000000000000 R15: 0000000000000000 [ 30.349672] FS: 0000000000000000(0000) GS:ffff8801db200000(0063) knlGS:0000000009eab840 [ 30.357874] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 30.363728] CR2: ffff8800fffffff8 CR3: 00000001d04b4000 CR4: 0000000000160670 [ 30.370975] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.378220] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.385462] Stack: [ 30.387584] [ 30.389182] Call Trace: [ 30.391737] [ 30.393771] Code: df 06 00 e9 83 fd ff ff e8 78 df 06 00 e9 50 fd ff ff e8 6e df 06 00 e9 1d fd ff ff 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 <41> 56 41 55 49 89 f5 41 54 49 89 d4 53 48 89 fb 48 83 ec 08 e8 [ 31.124277] Shutting down cpus with NMI [ 31.129138] Dumping ftrace buffer: [ 31.132652] (ftrace buffer empty) [ 31.136340] Kernel Offset: disabled [ 31.139935] Rebooting in 86400 seconds..