INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added 'ci-upstream-next-kasan-gce-0,10.128.0.53' (ECDSA) to the list of known hosts. 2017/08/15 09:52:18 parsed 1 programs 2017/08/15 09:52:18 executed programs: 0 syzkaller login: [ 42.837005] ================================================================== [ 42.838168] BUG: KASAN: use-after-free in skb_release_data+0x5cf/0x790 [ 42.839042] Read of size 1 at addr ffff8801cab9fd42 by task syz-executor0/3729 [ 42.840002] [ 42.840233] CPU: 1 PID: 3729 Comm: syz-executor0 Not tainted 4.13.0-rc5-next-20170815+ #3 [ 42.841363] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.842595] Call Trace: [ 42.842948] dump_stack+0x194/0x257 [ 42.843443] ? arch_local_irq_restore+0x53/0x53 [ 42.844075] ? show_regs_print_info+0x65/0x65 [ 42.844679] ? skb_release_data+0x5cf/0x790 [ 42.845254] print_address_description+0x73/0x250 [ 42.845908] ? skb_release_data+0x5cf/0x790 [ 42.846547] kasan_report+0x24e/0x340 [ 42.847106] __asan_report_load1_noabort+0x14/0x20 [ 42.847757] skb_release_data+0x5cf/0x790 [ 42.848327] ? lock_downgrade+0x990/0x990 [ 42.848878] ? ip_route_input_rcu+0x1193/0x3210 [ 42.849569] ? do_raw_spin_trylock+0x190/0x190 [ 42.850177] ? skb_tx_error+0x2c0/0x2c0 [ 42.850713] ? __lock_is_held+0xb6/0x140 [ 42.851266] skb_release_all+0x4a/0x60 [ 42.851785] kfree_skb+0x15d/0x4c0 [ 42.852258] ? ip_defrag+0xc69/0x4000 [ 42.852767] ? __kfree_skb+0x20/0x20 [ 42.853311] ? lock_release+0xa40/0xa40 [ 42.853889] ? check_noncircular+0x20/0x20 [ 42.854481] ? ipqhashfn+0xb7/0x180 [ 42.854969] ? ip4_frag_match+0x370/0x370 [ 42.855525] ? percpu_counter_add_batch+0xce/0x130 [ 42.856197] ip_defrag+0xc69/0x4000 [ 42.856687] ? find_held_lock+0x3/0x1d0 [ 42.857701] ? ip_expire+0x6d0/0x6d0 [ 42.861377] ? lock_downgrade+0x990/0x990 [ 42.865498] ? lock_release+0xa40/0xa40 [ 42.869446] ip_local_deliver+0x174/0x6d0 [ 42.873560] ? ip_call_ra_chain+0x6d0/0x6d0 [ 42.877849] ? ip_route_input_noref+0x13c/0x1e0 [ 42.882484] ? ip_route_input_rcu+0x3210/0x3210 [ 42.887115] ? print_usage_bug+0x480/0x480 [ 42.891312] ? print_usage_bug+0x480/0x480 [ 42.895516] ? check_noncircular+0x20/0x20 [ 42.899721] ip_rcv_finish+0x8db/0x19c0 [ 42.903672] ? ip_local_deliver_finish+0xba0/0xba0 [ 42.908572] ? ip_rcv+0xf05/0x17d0 [ 42.912075] ? lock_downgrade+0x990/0x990 [ 42.916198] ? lock_release+0xa40/0xa40 [ 42.920138] ? __lock_is_held+0xb6/0x140 [ 42.924174] ip_rcv+0xc3f/0x17d0 [ 42.927510] ? ip_local_deliver+0x6d0/0x6d0 [ 42.931794] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 42.936951] ? __lock_acquire+0x6aa/0x3bc0 [ 42.941153] ? __lock_is_held+0xb6/0x140 [ 42.945183] ? ip_local_deliver+0x6d0/0x6d0 [ 42.949476] __netif_receive_skb_core+0x19af/0x33d0 [ 42.954465] ? unwind_get_return_address+0x61/0xa0 [ 42.959367] ? nf_ingress+0x9f0/0x9f0 [ 42.963136] ? save_stack+0xa3/0xd0 [ 42.966727] ? save_stack_trace+0x16/0x20 [ 42.970836] ? save_stack+0x43/0xd0 [ 42.974424] ? kasan_kmalloc+0xad/0xe0 [ 42.978272] ? kasan_slab_alloc+0x12/0x20 [ 42.982380] ? kmem_cache_alloc+0x12e/0x760 [ 42.986664] ? __build_skb+0x9d/0x450 [ 42.990428] ? build_skb+0x6f/0x260 [ 42.994022] ? tun_get_user+0x1db7/0x2150 [ 42.998133] ? tun_chr_write_iter+0xd8/0x190 [ 43.002508] ? __vfs_write+0x684/0x970 [ 43.006367] ? vfs_write+0x189/0x510 [ 43.010088] ? SyS_write+0xef/0x220 [ 43.013706] ? entry_SYSCALL_64_fastpath+0x1f/0xbe [ 43.018929] ? check_preempt_wakeup+0x1320/0x1320 [ 43.023745] ? check_noncircular+0x20/0x20 [ 43.027948] ? check_noncircular+0x20/0x20 [ 43.032148] ? update_load_avg+0x1231/0x2a90 [ 43.036527] ? __skb_flow_dissect+0xfa1/0x3ae0 [ 43.041082] ? __lock_acquire+0x5d0/0x3bc0 [ 43.045289] ? __skb_flow_get_ports+0x400/0x400 [ 43.049938] ? find_held_lock+0x35/0x1d0 [ 43.053998] ? netif_receive_skb_internal+0x1d7/0x5e0 [ 43.059179] ? lock_downgrade+0x990/0x990 [ 43.063333] ? pvclock_read_flags+0x160/0x160 [ 43.067823] ? lock_acquire+0x1d5/0x580 [ 43.071795] ? lock_acquire+0x1d5/0x580 [ 43.075757] ? netif_receive_skb_internal+0x93/0x5e0 [ 43.080843] ? ktime_get_with_offset+0x2c1/0x420 [ 43.085584] ? lock_release+0xa40/0xa40 [ 43.089523] ? do_gettimeofday+0x190/0x190 [ 43.093737] __netif_receive_skb+0x2c/0x1b0 [ 43.098033] ? __netif_receive_skb+0x2c/0x1b0 [ 43.102506] netif_receive_skb_internal+0x10b/0x5e0 [ 43.107489] ? dev_cpu_dead+0xb00/0xb00 [ 43.111439] ? tun_device_event+0xca0/0xca0 [ 43.115728] ? check_noncircular+0x20/0x20 [ 43.119929] ? rcu_pm_notify+0xc0/0xc0 [ 43.123793] netif_receive_skb+0xae/0x390 [ 43.127907] ? netif_receive_skb_internal+0x5e0/0x5e0 [ 43.133063] ? find_held_lock+0x35/0x1d0 [ 43.137098] ? tun_rx_batched.isra.43+0x5bd/0x860 [ 43.141911] tun_rx_batched.isra.43+0x5e7/0x860 [ 43.146548] ? skb_get_hash_perturb+0x9d0/0x9d0 [ 43.151184] ? tun_sock_write_space+0x370/0x370 [ 43.155818] ? compat_start_thread+0x80/0x80 [ 43.160192] ? tun_free_netdev+0x1b0/0x1b0 [ 43.164405] ? check_noncircular+0x20/0x20 [ 43.168610] tun_get_user+0x11dd/0x2150 [ 43.172564] ? tun_flow_update+0xf70/0xf70 [ 43.176771] ? __tun_get+0x1ab/0x2e0 [ 43.180457] ? lock_downgrade+0x990/0x990 [ 43.184575] ? lock_release+0xa40/0xa40 [ 43.188520] ? __lock_is_held+0xb6/0x140 [ 43.192559] ? __tun_get+0x1d4/0x2e0 [ 43.196239] ? tun_chr_close+0x60/0x60 [ 43.200118] tun_chr_write_iter+0xd8/0x190 [ 43.204325] __vfs_write+0x684/0x970 [ 43.208016] ? default_llseek+0x290/0x290 [ 43.212155] ? _cond_resched+0x14/0x30 [ 43.216018] ? avc_policy_seqno+0x9/0x20 [ 43.220058] ? selinux_file_permission+0x82/0x460 [ 43.224878] ? rw_verify_area+0xe5/0x2b0 [ 43.228906] ? __fdget_raw+0x20/0x20 [ 43.232589] vfs_write+0x189/0x510 [ 43.236099] SyS_write+0xef/0x220 [ 43.239522] ? SyS_read+0x220/0x220 [ 43.243117] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.248101] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 43.252832] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 43.257553] RIP: 0033:0x40b751 [ 43.260706] RSP: 002b:00007f1a76bbac10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 [ 43.268379] RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 000000000040b751 [ 43.275614] RDX: 000000000000002a RSI: 0000000020a71fd0 RDI: 0000000000000003 [ 43.282853] RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 [ 43.290091] R10: 00000000000f4246 R11: 0000000000000293 R12: 00000000004be638 [ 43.297326] R13: 00000000ffffffff R14: 0000000000000009 R15: 0000000000000000 [ 43.304581] [ 43.306174] The buggy address belongs to the page: [ 43.311070] page:ffffea00072ae7c0 count:0 mapcount:0 mapping: (null) index:0x0 [ 43.319176] flags: 0x200000000000000() [ 43.323032] raw: 0200000000000000 0000000000000000 0000000000000000 00000000ffffffff [ 43.330879] raw: 0000000000000000 0000000100000001 0000000000000000 0000000000000000 [ 43.338720] page dumped because: kasan: bad access detected [ 43.344392] [ 43.345982] Memory state around the buggy address: [ 43.350880] ffff8801cab9fc00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 43.358204] ffff8801cab9fc80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 43.365525] >ffff8801cab9fd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 43.372850] ^ [ 43.378265] ffff8801cab9fd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 43.385588] ffff8801cab9fe00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 43.392908] ================================================================== [ 43.400237] Disabling lock debugging due to kernel taint [ 43.405736] Kernel panic - not syncing: panic_on_warn set ... [ 43.405736] [ 43.413085] CPU: 1 PID: 3729 Comm: syz-executor0 Tainted: G B 4.13.0-rc5-next-20170815+ #3 [ 43.422593] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.431926] Call Trace: [ 43.434505] dump_stack+0x194/0x257 [ 43.438119] ? arch_local_irq_restore+0x53/0x53 [ 43.442774] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 43.447520] ? skb_release_data+0x520/0x790 [ 43.451808] panic+0x1e4/0x417 [ 43.454965] ? __warn+0x1d9/0x1d9 [ 43.458385] ? skb_release_data+0x5cf/0x790 [ 43.462672] kasan_end_report+0x50/0x50 [ 43.466610] kasan_report+0x137/0x340 [ 43.470378] __asan_report_load1_noabort+0x14/0x20 [ 43.475273] skb_release_data+0x5cf/0x790 [ 43.479397] ? lock_downgrade+0x990/0x990 [ 43.483511] ? ip_route_input_rcu+0x1193/0x3210 [ 43.488145] ? do_raw_spin_trylock+0x190/0x190 [ 43.492692] ? skb_tx_error+0x2c0/0x2c0 [ 43.496636] ? __lock_is_held+0xb6/0x140 [ 43.500668] skb_release_all+0x4a/0x60 [ 43.504519] kfree_skb+0x15d/0x4c0 [ 43.508028] ? ip_defrag+0xc69/0x4000 [ 43.511799] ? __kfree_skb+0x20/0x20 [ 43.515477] ? lock_release+0xa40/0xa40 [ 43.519419] ? check_noncircular+0x20/0x20 [ 43.523621] ? ipqhashfn+0xb7/0x180 [ 43.527212] ? ip4_frag_match+0x370/0x370 [ 43.531325] ? percpu_counter_add_batch+0xce/0x130 [ 43.536221] ip_defrag+0xc69/0x4000 [ 43.539814] ? find_held_lock+0x3/0x1d0 [ 43.543758] ? ip_expire+0x6d0/0x6d0 [ 43.547439] ? lock_downgrade+0x990/0x990 [ 43.551555] ? lock_release+0xa40/0xa40 [ 43.555504] ip_local_deliver+0x174/0x6d0 [ 43.559617] ? ip_call_ra_chain+0x6d0/0x6d0 [ 43.563903] ? ip_route_input_noref+0x13c/0x1e0 [ 43.568534] ? ip_route_input_rcu+0x3210/0x3210 [ 43.573166] ? print_usage_bug+0x480/0x480 [ 43.577364] ? print_usage_bug+0x480/0x480 [ 43.581564] ? check_noncircular+0x20/0x20 [ 43.585763] ip_rcv_finish+0x8db/0x19c0 [ 43.589703] ? ip_local_deliver_finish+0xba0/0xba0 [ 43.594598] ? ip_rcv+0xf05/0x17d0 [ 43.598102] ? lock_downgrade+0x990/0x990 [ 43.602220] ? lock_release+0xa40/0xa40 [ 43.606159] ? __lock_is_held+0xb6/0x140 [ 43.610189] ip_rcv+0xc3f/0x17d0 [ 43.613523] ? ip_local_deliver+0x6d0/0x6d0 [ 43.617808] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 43.622962] ? __lock_acquire+0x6aa/0x3bc0 [ 43.627166] ? __lock_is_held+0xb6/0x140 [ 43.631194] ? ip_local_deliver+0x6d0/0x6d0 [ 43.635486] __netif_receive_skb_core+0x19af/0x33d0 [ 43.640468] ? unwind_get_return_address+0x61/0xa0 [ 43.645364] ? nf_ingress+0x9f0/0x9f0 [ 43.649130] ? save_stack+0xa3/0xd0 [ 43.652753] ? save_stack_trace+0x16/0x20 [ 43.656865] ? save_stack+0x43/0xd0 [ 43.660452] ? kasan_kmalloc+0xad/0xe0 [ 43.664300] ? kasan_slab_alloc+0x12/0x20 [ 43.668411] ? kmem_cache_alloc+0x12e/0x760 [ 43.672697] ? __build_skb+0x9d/0x450 [ 43.676461] ? build_skb+0x6f/0x260 [ 43.680052] ? tun_get_user+0x1db7/0x2150 [ 43.684161] ? tun_chr_write_iter+0xd8/0x190 [ 43.688534] ? __vfs_write+0x684/0x970 [ 43.692382] ? vfs_write+0x189/0x510 [ 43.696058] ? SyS_write+0xef/0x220 [ 43.699649] ? entry_SYSCALL_64_fastpath+0x1f/0xbe [ 43.704544] ? check_preempt_wakeup+0x1320/0x1320 [ 43.709354] ? check_noncircular+0x20/0x20 [ 43.713553] ? check_noncircular+0x20/0x20 [ 43.717750] ? update_load_avg+0x1231/0x2a90 [ 43.722123] ? __skb_flow_dissect+0xfa1/0x3ae0 [ 43.726671] ? __lock_acquire+0x5d0/0x3bc0 [ 43.730872] ? __skb_flow_get_ports+0x400/0x400 [ 43.735506] ? find_held_lock+0x35/0x1d0 [ 43.739535] ? netif_receive_skb_internal+0x1d7/0x5e0 [ 43.744687] ? lock_downgrade+0x990/0x990 [ 43.748803] ? pvclock_read_flags+0x160/0x160 [ 43.753269] ? lock_acquire+0x1d5/0x580 [ 43.757208] ? lock_acquire+0x1d5/0x580 [ 43.761147] ? netif_receive_skb_internal+0x93/0x5e0 [ 43.766217] ? ktime_get_with_offset+0x2c1/0x420 [ 43.770939] ? lock_release+0xa40/0xa40 [ 43.774876] ? do_gettimeofday+0x190/0x190 [ 43.779081] __netif_receive_skb+0x2c/0x1b0 [ 43.783376] ? __netif_receive_skb+0x2c/0x1b0 [ 43.787836] netif_receive_skb_internal+0x10b/0x5e0 [ 43.792816] ? dev_cpu_dead+0xb00/0xb00 [ 43.796757] ? tun_device_event+0xca0/0xca0 [ 43.801043] ? check_noncircular+0x20/0x20 [ 43.805244] ? rcu_pm_notify+0xc0/0xc0 [ 43.809108] netif_receive_skb+0xae/0x390 [ 43.813222] ? netif_receive_skb_internal+0x5e0/0x5e0 [ 43.818376] ? find_held_lock+0x35/0x1d0 [ 43.822405] ? tun_rx_batched.isra.43+0x5bd/0x860 [ 43.827214] tun_rx_batched.isra.43+0x5e7/0x860 [ 43.831849] ? skb_get_hash_perturb+0x9d0/0x9d0 [ 43.836483] ? tun_sock_write_space+0x370/0x370