[ 15.926390] random: sshd: uninitialized urandom read (32 bytes read, 32 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: [ 21.294666] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.625224] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 22.400125] random: sshd: uninitialized urandom read (32 bytes read, 82 bits of entropy available) [ 28.528843] random: sshd: uninitialized urandom read (32 bytes read, 92 bits of entropy available) Warning: Permanently added '10.128.0.63' (ECDSA) to the list of known hosts. [ 33.870033] random: sshd: uninitialized urandom read (32 bytes read, 94 bits of entropy available) 2018/01/15 21:56:05 parsed 1 programs 2018/01/15 21:56:05 executed programs: 0 [ 34.166875] IPVS: Creating netns size=2552 id=1 [ 34.203076] IPVS: Creating netns size=2552 id=2 [ 34.237978] IPVS: Creating netns size=2552 id=3 [ 34.263563] IPVS: Creating netns size=2552 id=4 [ 34.301018] IPVS: Creating netns size=2552 id=5 [ 34.338125] IPVS: Creating netns size=2552 id=6 [ 34.374919] IPVS: Creating netns size=2552 id=7 [ 34.404367] IPVS: Creating netns size=2552 id=8 2018/01/15 21:56:10 executed programs: 288 [ 41.867120] ================================================================== [ 41.874566] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 41.881210] Read of size 8 at addr ffff8800b209ef20 by task syz-executor1/4998 [ 41.888535] [ 41.890134] CPU: 0 PID: 4998 Comm: syz-executor1 Not tainted 4.4.111-gc2f631b #20 [ 41.897719] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.907041] 0000000000000000 be3092bea7ef5290 ffff8801ce12f550 ffffffff81d0513d [ 41.914999] ffffea0002c82600 ffff8800b209ef20 0000000000000000 ffff8800b209ef20 [ 41.922949] 0000000000000000 ffff8801ce12f588 ffffffff814fd433 ffff8800b209ef20 [ 41.930899] Call Trace: [ 41.933459] [] dump_stack+0xc1/0x124 [ 41.938792] [] print_address_description+0x73/0x260 [ 41.945425] [] kasan_report+0x285/0x370 [ 41.951017] [] ? __lock_acquire+0x387e/0x4b50 [ 41.957129] [] __asan_report_load8_noabort+0x14/0x20 [ 41.963849] [] __lock_acquire+0x387e/0x4b50 [ 41.969788] [] ? dump_trace+0x14c/0x350 [ 41.975380] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 41.982362] [] ? free_fs_struct+0x4f/0x60 [ 41.988137] [] ? save_stack+0xa3/0xd0 [ 41.993563] [] ? do_exit+0x84a/0x2a20 [ 41.998982] [] ? do_group_exit+0x108/0x320 [ 42.004838] [] ? get_signal+0x565/0x1660 [ 42.010524] [] ? do_signal+0x8b/0x1d40 [ 42.016028] [] ? exit_to_usermode_loop+0x122/0x170 [ 42.022581] [] ? sysenter_flags_fixed+0xd/0x17 [ 42.028782] [] lock_acquire+0x15e/0x460 [ 42.034380] [] ? lock_sock_nested+0x43/0x120 [ 42.040418] [] ? get_parent_ip+0xd/0x50 [ 42.046029] [] ? sock_release+0x1e0/0x1e0 [ 42.051798] [] _raw_spin_lock_bh+0x3a/0x50 [ 42.057661] [] ? lock_sock_nested+0x43/0x120 [ 42.063688] [] lock_sock_nested+0x43/0x120 [ 42.069542] [] pppol2tp_release+0x50/0x310 [ 42.075451] [] sock_release+0x8d/0x1e0 [ 42.080979] [] sock_close+0x16/0x20 [ 42.086234] [] __fput+0x233/0x6d0 [ 42.091315] [] ____fput+0x15/0x20 [ 42.096389] [] task_work_run+0x104/0x180 [ 42.102069] [] do_exit+0x871/0x2a20 [ 42.107529] [] ? release_task+0x1240/0x1240 [ 42.113479] [] ? save_stack+0xa3/0xd0 [ 42.118897] [] ? recalc_sigpending+0x76/0xa0 [ 42.124922] [] do_group_exit+0x108/0x320 [ 42.130597] [] get_signal+0x565/0x1660 [ 42.136104] [] ? quarantine_put+0xab/0x180 [ 42.141956] [] do_signal+0x8b/0x1d40 [ 42.147286] [] ? mntput_no_expire+0xca/0x680 [ 42.153311] [] ? setup_sigcontext+0x780/0x780 [ 42.159425] [] ? sock_release+0x1e0/0x1e0 [ 42.165191] [] ? mntput_no_expire+0xf6/0x680 [ 42.171221] [] ? mnt_get_count+0x190/0x190 [ 42.177075] [] ? dput.part.19+0x16d/0x760 [ 42.182842] [] ? dput.part.19+0x2a/0x760 [ 42.188525] [] ? sock_release+0x1e0/0x1e0 [ 42.194303] [] ? exit_to_usermode_loop+0xec/0x170 [ 42.200764] [] exit_to_usermode_loop+0x122/0x170 [ 42.207141] [] do_fast_syscall_32+0x607/0x890 [ 42.213270] [] sysenter_flags_fixed+0xd/0x17 [ 42.219290] [ 42.220885] Allocated by task 5006: [ 42.224481] [] save_stack_trace+0x26/0x50 [ 42.230365] [] save_stack+0x43/0xd0 [ 42.235723] [] kasan_kmalloc+0xad/0xe0 [ 42.241353] [] __kmalloc+0x124/0x320 [ 42.246815] [] sk_prot_alloc+0x18c/0x310 [ 42.252615] [] sk_alloc+0x3a/0x3a0 [ 42.257896] [] pppol2tp_create+0x33/0x1f0 [ 42.263776] [] pppox_create+0xf1/0x200 [ 42.269395] [] __sock_create+0x3ac/0x640 [ 42.275206] [] SyS_socket+0xf0/0x1b0 [ 42.280654] [] do_fast_syscall_32+0x314/0x890 [ 42.286885] [] sysenter_flags_fixed+0xd/0x17 [ 42.293024] [ 42.294623] Freed by task 4998: [ 42.297881] [] save_stack_trace+0x26/0x50 [ 42.303761] [] save_stack+0x43/0xd0 [ 42.309128] [] kasan_slab_free+0x72/0xc0 [ 42.314915] [] kfree+0xfc/0x300 [ 42.319928] [] sk_destruct+0x3f7/0x4c0 [ 42.325547] [] __sk_free+0x57/0x230 [ 42.330911] [] sk_free+0x30/0x40 [ 42.336008] [] pppol2tp_session_sock_put+0x5f/0x70 [ 42.342667] [] l2tp_tunnel_closeall+0x254/0x3b0 [ 42.349079] [] l2tp_udp_encap_destroy+0x8b/0xf0 [ 42.355479] [] udpv6_destroy_sock+0xb1/0xd0 [ 42.361542] [] sk_common_release+0x6b/0x300 [ 42.367595] [] udp_lib_close+0x15/0x20 [ 42.373212] [] inet_release+0xfa/0x1d0 [ 42.378852] [] inet6_release+0x50/0x70 [ 42.384472] [] sock_release+0x8d/0x1e0 [ 42.390089] [] sock_close+0x16/0x20 [ 42.395542] [] __fput+0x233/0x6d0 [ 42.400726] [] ____fput+0x15/0x20 [ 42.405926] [] task_work_run+0x104/0x180 [ 42.411737] [] exit_to_usermode_loop+0x145/0x170 [ 42.418243] [] do_fast_syscall_32+0x607/0x890 [ 42.424491] [] sysenter_flags_fixed+0xd/0x17 [ 42.430657] [ 42.432256] The buggy address belongs to the object at ffff8800b209ee80 [ 42.432256] which belongs to the cache kmalloc-2048 of size 2048 [ 42.445067] The buggy address is located 160 bytes inside of [ 42.445067] 2048-byte region [ffff8800b209ee80, ffff8800b209f680) [ 42.457011] The buggy address belongs to the page: [ 43.886766] PANIC: double fault, error_code: 0x0 [ 43.891547] CPU: 0 PID: 4998 Comm: syz-executor1 Not tainted 4.4.111-gc2f631b #20 [ 43.899130] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.908450] task: ffff8800b22217c0 task.stack: ffff8801ce128000 [ 43.914469] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 43.923304] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 43.928720] RAX: ffff8800b22217c0 RBX: ffffea0002c82600 RCX: ffffffff8148f980 [ 43.935954] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea0002c82600 [ 43.943189] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 43.950425] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 43.957666] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 43.964904] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 43.973268] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 43.979118] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 43.986356] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 43.993592] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 44.000825] Stack: [ 44.002936] [ 44.004527] Call Trace: [ 44.007081] [ 44.009109] Code: e2 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 61 06 ed ff 48 8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 [ 44.035705] Kernel panic - not syncing: Machine halted. [ 44.041034] CPU: 0 PID: 4998 Comm: syz-executor1 Not tainted 4.4.111-gc2f631b #20 [ 44.048790] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.058115] 0000000000000000 be3092bea7ef5290 ffff8801db20ce38 ffffffff81d0513d [ 44.066088] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 44.074042] 0000000000000000 ffff8801db20cf00 ffffffff81419a3a 0000000041b58ab3 [ 44.081996] Call Trace: [ 44.084559] <#DF> [] dump_stack+0xc1/0x124 [ 44.090622] [] panic+0x1aa/0x388 [ 44.095604] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 44.102502] [] ? vprintk_emit+0x242/0x850 [ 44.108265] [] ? dump_page_badflags+0x2f/0x250 [ 44.114465] [] ? vprintk_emit+0x242/0x850 [ 44.120230] [] df_debug+0x2d/0x30 [ 44.125303] [] do_double_fault+0x10b/0x210 [ 44.131158] [] double_fault+0x2d/0x40 [ 44.136576] [] ? dump_page_badflags+0x180/0x250 [ 44.142865] [] ? dump_page_badflags+0x1a/0x250 [ 44.149057] <> [ 44.152406] Dumping ftrace buffer: [ 44.156204] (ftrace buffer empty) [ 44.159878] Kernel Offset: disabled [ 44.163469] Rebooting in 86400 seconds..