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-kasan-gce-3,10.128.15.221' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 31.184680] ================================================================== [ 31.192146] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 31.199135] Write of size 8 at addr ffff8801cc4236c8 by task syzkaller777063/3042 [ 31.206728] [ 31.208334] CPU: 1 PID: 3042 Comm: syzkaller777063 Not tainted 4.13.0+ #69 [ 31.215315] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.224642] Call Trace: [ 31.227207] dump_stack+0x194/0x257 [ 31.230814] ? arch_local_irq_restore+0x53/0x53 [ 31.235457] ? show_regs_print_info+0x65/0x65 [ 31.239930] ? __kernel_text_address+0xae/0xe0 [ 31.244489] ? __internal_add_timer+0x275/0x2d0 [ 31.249134] print_address_description+0x73/0x250 [ 31.253952] ? __internal_add_timer+0x275/0x2d0 [ 31.258598] kasan_report+0x24e/0x340 [ 31.262379] __asan_report_store8_noabort+0x17/0x20 [ 31.267367] __internal_add_timer+0x275/0x2d0 [ 31.271855] ? calc_wheel_index+0x200/0x200 [ 31.276162] mod_timer+0x622/0x15b0 [ 31.279775] ? mod_timer_pending+0x14e0/0x14e0 [ 31.284331] ? __lock_is_held+0xbc/0x140 [ 31.288380] ? __lock_is_held+0xbc/0x140 [ 31.292432] ? __lockdep_init_map+0xe4/0x650 [ 31.296821] ? lockdep_init_map+0x3d/0x70 [ 31.300945] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.306022] ? init_timer_key+0x126/0x3b0 [ 31.310146] ? try_to_del_timer_sync+0x120/0x120 [ 31.314879] ? round_jiffies_up+0xce/0x100 [ 31.319085] ? __round_jiffies_up_relative+0x150/0x150 [ 31.324334] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 31.329239] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 31.334758] __tun_chr_ioctl+0x1b2c/0x3d70 [ 31.338974] ? tun_select_queue+0x580/0x580 [ 31.343281] ? lock_downgrade+0x990/0x990 [ 31.347430] ? check_same_owner+0x320/0x320 [ 31.351730] ? __handle_mm_fault+0x3840/0x3840 [ 31.356293] ? vmacache_find+0x61/0x270 [ 31.360243] ? tun_chr_compat_ioctl+0x30/0x30 [ 31.364711] tun_chr_ioctl+0x2a/0x40 [ 31.368397] ? tun_chr_ioctl+0x2a/0x40 [ 31.372259] do_vfs_ioctl+0x1b1/0x1530 [ 31.376125] ? ioctl_preallocate+0x2b0/0x2b0 [ 31.380522] ? selinux_capable+0x40/0x40 [ 31.384564] ? putname+0xf3/0x130 [ 31.388012] ? do_sys_open+0x320/0x6d0 [ 31.391885] ? security_file_ioctl+0x7d/0xb0 [ 31.396267] ? security_file_ioctl+0x89/0xb0 [ 31.400656] SyS_ioctl+0x8f/0xc0 [ 31.404024] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 31.408756] RIP: 0033:0x443d79 [ 31.411919] RSP: 002b:00007fff1ea27e58 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 31.419605] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d79 [ 31.426859] RDX: 0000000020bc5000 RSI: 00000000400454ca RDI: 0000000000000004 [ 31.434112] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 31.441356] R10: 0000000000000000 R11: 0000000000000202 R12: 36424a60a8486c28 [ 31.448599] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 31.455873] [ 31.457476] Allocated by task 3042: [ 31.461079] save_stack_trace+0x16/0x20 [ 31.465026] save_stack+0x43/0xd0 [ 31.468461] kasan_kmalloc+0xad/0xe0 [ 31.472146] __kmalloc_node+0x47/0x70 [ 31.475919] kvmalloc_node+0x64/0xd0 [ 31.479614] alloc_netdev_mqs+0x16e/0xed0 [ 31.483735] __tun_chr_ioctl+0x12be/0x3d70 [ 31.487950] tun_chr_ioctl+0x2a/0x40 [ 31.491637] do_vfs_ioctl+0x1b1/0x1530 [ 31.495506] SyS_ioctl+0x8f/0xc0 [ 31.498846] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 31.503570] [ 31.505169] Freed by task 3042: [ 31.508429] save_stack_trace+0x16/0x20 [ 31.512384] save_stack+0x43/0xd0 [ 31.515810] kasan_slab_free+0x71/0xc0 [ 31.519668] kfree+0xca/0x250 [ 31.522757] kvfree+0x36/0x60 [ 31.525837] free_netdev+0x2cf/0x360 [ 31.529521] __tun_chr_ioctl+0x2d30/0x3d70 [ 31.533726] tun_chr_ioctl+0x2a/0x40 [ 31.537412] do_vfs_ioctl+0x1b1/0x1530 [ 31.541269] SyS_ioctl+0x8f/0xc0 [ 31.544610] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 31.549337] [ 31.550938] The buggy address belongs to the object at ffff8801cc4202c0 [ 31.550938] which belongs to the cache kmalloc-16384 of size 16384 [ 31.563914] The buggy address is located 13320 bytes inside of [ 31.563914] 16384-byte region [ffff8801cc4202c0, ffff8801cc4242c0) [ 31.576386] The buggy address belongs to the page: [ 31.581289] page:ffffea0007310800 count:1 mapcount:0 mapping:ffff8801cc4202c0 index:0x0 compound_mapcount: 0 [ 31.591238] flags: 0x200000000008100(slab|head) [ 31.595880] raw: 0200000000008100 ffff8801cc4202c0 0000000000000000 0000000100000001 [ 31.603743] raw: ffffea00074ff420 ffffea000732da20 ffff8801dac02200 0000000000000000 [ 31.611610] page dumped because: kasan: bad access detected [ 31.617377] [ 31.618979] Memory state around the buggy address: [ 31.623882] ffff8801cc423580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.631228] ffff8801cc423600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.638558] >ffff8801cc423680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.645888] ^ [ 31.651580] ffff8801cc423700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.658912] ffff8801cc423780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.666252] ================================================================== [ 31.673581] Disabling lock debugging due to kernel taint [ 31.678998] Kernel panic - not syncing: panic_on_warn set ... [ 31.678998] [ 31.686326] CPU: 1 PID: 3042 Comm: syzkaller777063 Tainted: G B 4.13.0+ #69 [ 31.694517] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.703844] Call Trace: [ 31.706408] dump_stack+0x194/0x257 [ 31.710004] ? arch_local_irq_restore+0x53/0x53 [ 31.714644] ? vprintk_default+0x28/0x30 [ 31.718679] ? __internal_add_timer+0x250/0x2d0 [ 31.723320] panic+0x1e4/0x417 [ 31.726479] ? __warn+0x1d9/0x1d9 [ 31.729908] ? __internal_add_timer+0x275/0x2d0 [ 31.734564] kasan_end_report+0x50/0x50 [ 31.738506] kasan_report+0x137/0x340 [ 31.742286] __asan_report_store8_noabort+0x17/0x20 [ 31.747279] __internal_add_timer+0x275/0x2d0 [ 31.751749] ? calc_wheel_index+0x200/0x200 [ 31.756050] mod_timer+0x622/0x15b0 [ 31.759648] ? mod_timer_pending+0x14e0/0x14e0 [ 31.764198] ? __lock_is_held+0xbc/0x140 [ 31.768279] ? __lock_is_held+0xbc/0x140 [ 31.772307] ? __lockdep_init_map+0xe4/0x650 [ 31.776685] ? lockdep_init_map+0x3d/0x70 [ 31.780815] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.785800] ? init_timer_key+0x126/0x3b0 [ 31.789928] ? try_to_del_timer_sync+0x120/0x120 [ 31.794652] ? round_jiffies_up+0xce/0x100 [ 31.798853] ? __round_jiffies_up_relative+0x150/0x150 [ 31.804094] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 31.808992] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 31.814502] __tun_chr_ioctl+0x1b2c/0x3d70 [ 31.818722] ? tun_select_queue+0x580/0x580 [ 31.823017] ? lock_downgrade+0x990/0x990 [ 31.827145] ? check_same_owner+0x320/0x320 [ 31.831435] ? __handle_mm_fault+0x3840/0x3840 [ 31.835983] ? vmacache_find+0x61/0x270 [ 31.839934] ? tun_chr_compat_ioctl+0x30/0x30 [ 31.844395] tun_chr_ioctl+0x2a/0x40 [ 31.848087] ? tun_chr_ioctl+0x2a/0x40 [ 31.851956] do_vfs_ioctl+0x1b1/0x1530 [ 31.855813] ? ioctl_preallocate+0x2b0/0x2b0 [ 31.860190] ? selinux_capable+0x40/0x40 [ 31.864223] ? putname+0xf3/0x130 [ 31.867646] ? do_sys_open+0x320/0x6d0 [ 31.871505] ? security_file_ioctl+0x7d/0xb0 [ 31.875879] ? security_file_ioctl+0x89/0xb0 [ 31.880256] SyS_ioctl+0x8f/0xc0 [ 31.883594] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 31.888318] RIP: 0033:0x443d79 [ 31.891476] RSP: 002b:00007fff1ea27e58 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 31.899162] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d79 [ 31.906497] RDX: 0000000020bc5000 RSI: 00000000400454ca RDI: 0000000000000004 [ 31.913733] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 31.920971] R10: 0000000000000000 R11: 0000000000000202 R12: 36424a60a8486c28 [ 31.928220] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 31.935511] Dumping ftrace buffer: [ 31.939023] (ftrace buffer empty) [ 31.942704] Kernel Offset: disabled [ 31.946302] Rebooting in 86400 seconds..