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-2,10.128.0.3' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 38.547907] ================================================================== [ 38.555319] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 38.562303] Write of size 8 at addr ffff8801ce55b6c8 by task syzkaller469057/2981 [ 38.569889] [ 38.571488] CPU: 1 PID: 2981 Comm: syzkaller469057 Not tainted 4.13.0-next-20170913+ #21 [ 38.579680] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.589004] Call Trace: [ 38.591561] dump_stack+0x194/0x257 [ 38.595166] ? arch_local_irq_restore+0x53/0x53 [ 38.599804] ? show_regs_print_info+0x65/0x65 [ 38.604274] ? __internal_add_timer+0x275/0x2d0 [ 38.608916] print_address_description+0x73/0x250 [ 38.613727] ? __internal_add_timer+0x275/0x2d0 [ 38.618371] kasan_report+0x24e/0x340 [ 38.622156] __asan_report_store8_noabort+0x17/0x20 [ 38.627141] __internal_add_timer+0x275/0x2d0 [ 38.631607] ? calc_wheel_index+0x200/0x200 [ 38.635908] mod_timer+0x622/0x15b0 [ 38.639513] ? mod_timer_pending+0x14e0/0x14e0 [ 38.644064] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 38.649050] ? trace_hardirqs_on+0xd/0x10 [ 38.653170] ? _crng_backtrack_protect+0xd9/0x130 [ 38.657990] ? __lock_is_held+0xbc/0x140 [ 38.662021] ? __lockdep_init_map+0xe4/0x650 [ 38.666402] ? lockdep_init_map+0x3d/0x70 [ 38.670518] ? rcu_read_lock_sched_held+0x108/0x120 [ 38.675506] ? init_timer_key+0x126/0x3b0 [ 38.679623] ? try_to_del_timer_sync+0x120/0x120 [ 38.684357] ? round_jiffies_up+0xce/0x100 [ 38.688601] ? __round_jiffies_up_relative+0x150/0x150 [ 38.693855] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 38.698765] __tun_chr_ioctl+0x1b23/0x3d20 [ 38.702978] ? tun_chr_read_iter+0x1e0/0x1e0 [ 38.707366] ? lock_downgrade+0x990/0x990 [ 38.711507] ? check_same_owner+0x320/0x320 [ 38.715799] ? __handle_mm_fault+0x39c0/0x39c0 [ 38.720348] ? vmacache_find+0x61/0x270 [ 38.724305] ? tun_chr_compat_ioctl+0x30/0x30 [ 38.728769] tun_chr_ioctl+0x2a/0x40 [ 38.732450] ? tun_chr_ioctl+0x2a/0x40 [ 38.736310] do_vfs_ioctl+0x1b1/0x1530 [ 38.740179] ? ioctl_preallocate+0x2b0/0x2b0 [ 38.744558] ? selinux_capable+0x40/0x40 [ 38.748592] ? putname+0xf3/0x130 [ 38.752018] ? do_sys_open+0x320/0x6d0 [ 38.755883] ? security_file_ioctl+0x7d/0xb0 [ 38.760260] ? security_file_ioctl+0x89/0xb0 [ 38.764640] SyS_ioctl+0x8f/0xc0 [ 38.767983] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 38.772706] RIP: 0033:0x443db9 [ 38.775863] RSP: 002b:00007ffd030192c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 38.783541] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443db9 [ 38.790785] RDX: 0000000020521fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 38.798024] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 38.805262] R10: 0000000000000000 R11: 0000000000000202 R12: 4f2c96c3699c0cef [ 38.812502] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 38.819757] [ 38.821353] Allocated by task 2981: [ 38.824952] save_stack_trace+0x16/0x20 [ 38.828898] save_stack+0x43/0xd0 [ 38.832319] kasan_kmalloc+0xad/0xe0 [ 38.836001] __kmalloc_node+0x47/0x70 [ 38.839773] kvmalloc_node+0x64/0xd0 [ 38.843457] alloc_netdev_mqs+0x16e/0xed0 [ 38.847572] __tun_chr_ioctl+0x12be/0x3d20 [ 38.851773] tun_chr_ioctl+0x2a/0x40 [ 38.855453] do_vfs_ioctl+0x1b1/0x1530 [ 38.859308] SyS_ioctl+0x8f/0xc0 [ 38.862643] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 38.867364] [ 38.868960] Freed by task 2981: [ 38.872209] save_stack_trace+0x16/0x20 [ 38.876148] save_stack+0x43/0xd0 [ 38.879569] kasan_slab_free+0x71/0xc0 [ 38.883426] kfree+0xca/0x250 [ 38.886502] kvfree+0x36/0x60 [ 38.889577] free_netdev+0x2cf/0x360 [ 38.893259] __tun_chr_ioctl+0x2cf6/0x3d20 [ 38.897464] tun_chr_ioctl+0x2a/0x40 [ 38.901148] do_vfs_ioctl+0x1b1/0x1530 [ 38.905000] SyS_ioctl+0x8f/0xc0 [ 38.908336] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 38.913056] [ 38.914653] The buggy address belongs to the object at ffff8801ce5582c0 [ 38.914653] which belongs to the cache kmalloc-16384 of size 16384 [ 38.927621] The buggy address is located 13320 bytes inside of [ 38.927621] 16384-byte region [ffff8801ce5582c0, ffff8801ce55c2c0) [ 38.939813] The buggy address belongs to the page: [ 38.944708] page:ffffea0007395600 count:1 mapcount:0 mapping:ffff8801ce5582c0 index:0x0 compound_mapcount: 0 [ 38.954648] flags: 0x200000000008100(slab|head) [ 38.959286] raw: 0200000000008100 ffff8801ce5582c0 0000000000000000 0000000100000001 [ 38.967133] raw: ffffea0007554220 ffffea000739da20 ffff8801dac02200 0000000000000000 [ 38.974978] page dumped because: kasan: bad access detected [ 38.980652] [ 38.982249] Memory state around the buggy address: [ 38.987147] ffff8801ce55b580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.994473] ffff8801ce55b600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 39.001799] >ffff8801ce55b680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 39.009122] ^ [ 39.014798] ffff8801ce55b700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 39.022123] ffff8801ce55b780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 39.029446] ================================================================== [ 39.036770] Disabling lock debugging due to kernel taint [ 39.042179] Kernel panic - not syncing: panic_on_warn set ... [ 39.042179] [ 39.049503] CPU: 1 PID: 2981 Comm: syzkaller469057 Tainted: G B 4.13.0-next-20170913+ #21 [ 39.058905] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 39.068222] Call Trace: [ 39.070775] dump_stack+0x194/0x257 [ 39.074367] ? arch_local_irq_restore+0x53/0x53 [ 39.079000] ? vprintk_default+0x28/0x30 [ 39.083027] ? __internal_add_timer+0x1f0/0x2d0 [ 39.087658] panic+0x1e4/0x417 [ 39.090813] ? __warn+0x1d9/0x1d9 [ 39.094235] ? __internal_add_timer+0x275/0x2d0 [ 39.098869] kasan_end_report+0x50/0x50 [ 39.102805] kasan_report+0x137/0x340 [ 39.106574] __asan_report_store8_noabort+0x17/0x20 [ 39.111552] __internal_add_timer+0x275/0x2d0 [ 39.116011] ? calc_wheel_index+0x200/0x200 [ 39.120303] mod_timer+0x622/0x15b0 [ 39.123898] ? mod_timer_pending+0x14e0/0x14e0 [ 39.128443] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 39.133424] ? trace_hardirqs_on+0xd/0x10 [ 39.137539] ? _crng_backtrack_protect+0xd9/0x130 [ 39.142349] ? __lock_is_held+0xbc/0x140 [ 39.146375] ? __lockdep_init_map+0xe4/0x650 [ 39.150748] ? lockdep_init_map+0x3d/0x70 [ 39.154860] ? rcu_read_lock_sched_held+0x108/0x120 [ 39.159839] ? init_timer_key+0x126/0x3b0 [ 39.163950] ? try_to_del_timer_sync+0x120/0x120 [ 39.168673] ? round_jiffies_up+0xce/0x100 [ 39.172870] ? __round_jiffies_up_relative+0x150/0x150 [ 39.178109] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 39.183008] __tun_chr_ioctl+0x1b23/0x3d20 [ 39.187212] ? tun_chr_read_iter+0x1e0/0x1e0 [ 39.191598] ? lock_downgrade+0x990/0x990 [ 39.195723] ? check_same_owner+0x320/0x320 [ 39.200007] ? __handle_mm_fault+0x39c0/0x39c0 [ 39.204552] ? vmacache_find+0x61/0x270 [ 39.208490] ? tun_chr_compat_ioctl+0x30/0x30 [ 39.212949] tun_chr_ioctl+0x2a/0x40 [ 39.216624] ? tun_chr_ioctl+0x2a/0x40 [ 39.220474] do_vfs_ioctl+0x1b1/0x1530 [ 39.224329] ? ioctl_preallocate+0x2b0/0x2b0 [ 39.228703] ? selinux_capable+0x40/0x40 [ 39.232726] ? putname+0xf3/0x130 [ 39.236147] ? do_sys_open+0x320/0x6d0 [ 39.240001] ? security_file_ioctl+0x7d/0xb0 [ 39.244371] ? security_file_ioctl+0x89/0xb0 [ 39.248744] SyS_ioctl+0x8f/0xc0 [ 39.252078] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 39.256795] RIP: 0033:0x443db9 [ 39.259947] RSP: 002b:00007ffd030192c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 39.267616] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443db9 [ 39.274851] RDX: 0000000020521fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 39.282087] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 39.289327] R10: 0000000000000000 R11: 0000000000000202 R12: 4f2c96c3699c0cef [ 39.296559] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 39.303836] Dumping ftrace buffer: [ 39.307341] (ftrace buffer empty) [ 39.311015] Kernel Offset: disabled [ 39.314605] Rebooting in 86400 seconds..