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-7,10.128.0.24' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 30.633197] ================================================================== [ 30.640629] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 30.647610] Write of size 8 at addr ffff8801ccb636c8 by task syzkaller799059/3036 [ 30.655199] [ 30.656799] CPU: 1 PID: 3036 Comm: syzkaller799059 Not tainted 4.13.0+ #70 [ 30.663781] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.673106] Call Trace: [ 30.675669] dump_stack+0x194/0x257 [ 30.679273] ? arch_local_irq_restore+0x53/0x53 [ 30.683913] ? show_regs_print_info+0x65/0x65 [ 30.688385] ? __kernel_text_address+0xae/0xe0 [ 30.692948] ? __internal_add_timer+0x275/0x2d0 [ 30.697592] print_address_description+0x73/0x250 [ 30.702415] ? __internal_add_timer+0x275/0x2d0 [ 30.707058] kasan_report+0x24e/0x340 [ 30.710835] __asan_report_store8_noabort+0x17/0x20 [ 30.715834] __internal_add_timer+0x275/0x2d0 [ 30.720306] ? calc_wheel_index+0x200/0x200 [ 30.724611] mod_timer+0x622/0x15b0 [ 30.728220] ? mod_timer_pending+0x14e0/0x14e0 [ 30.732778] ? __lock_is_held+0xbc/0x140 [ 30.736828] ? __lock_is_held+0xbc/0x140 [ 30.740880] ? __lockdep_init_map+0xe4/0x650 [ 30.745262] ? lockdep_init_map+0x3d/0x70 [ 30.749383] ? rcu_read_lock_sched_held+0x108/0x120 [ 30.754372] ? init_timer_key+0x126/0x3b0 [ 30.758492] ? try_to_del_timer_sync+0x120/0x120 [ 30.763221] ? round_jiffies_up+0xce/0x100 [ 30.767445] ? __round_jiffies_up_relative+0x150/0x150 [ 30.772707] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 30.777607] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 30.783125] __tun_chr_ioctl+0x1b2c/0x3d70 [ 30.787341] ? tun_select_queue+0x580/0x580 [ 30.791646] ? lock_downgrade+0x990/0x990 [ 30.795797] ? check_same_owner+0x320/0x320 [ 30.800093] ? __handle_mm_fault+0x3840/0x3840 [ 30.804642] ? vmacache_find+0x61/0x270 [ 30.808592] ? tun_chr_compat_ioctl+0x30/0x30 [ 30.813057] tun_chr_ioctl+0x2a/0x40 [ 30.816738] ? tun_chr_ioctl+0x2a/0x40 [ 30.820599] do_vfs_ioctl+0x1b1/0x1530 [ 30.824467] ? ioctl_preallocate+0x2b0/0x2b0 [ 30.828847] ? selinux_capable+0x40/0x40 [ 30.832881] ? putname+0xf3/0x130 [ 30.836320] ? do_sys_open+0x320/0x6d0 [ 30.840232] ? security_file_ioctl+0x7d/0xb0 [ 30.844607] ? security_file_ioctl+0x89/0xb0 [ 30.848987] SyS_ioctl+0x8f/0xc0 [ 30.852332] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 30.857058] RIP: 0033:0x443db9 [ 30.860218] RSP: 002b:00007ffd74f9e968 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 30.867897] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443db9 [ 30.875136] RDX: 0000000020115000 RSI: 00000000400454ca RDI: 0000000000000004 [ 30.882377] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 30.889616] R10: 0000000000000000 R11: 0000000000000206 R12: fdb4a8e95425e60d [ 30.896855] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 30.904150] [ 30.905782] Allocated by task 3036: [ 30.909380] save_stack_trace+0x16/0x20 [ 30.913323] save_stack+0x43/0xd0 [ 30.916744] kasan_kmalloc+0xad/0xe0 [ 30.920425] __kmalloc_node+0x47/0x70 [ 30.924194] kvmalloc_node+0x64/0xd0 [ 30.927878] alloc_netdev_mqs+0x16e/0xed0 [ 30.931995] __tun_chr_ioctl+0x12be/0x3d70 [ 30.936197] tun_chr_ioctl+0x2a/0x40 [ 30.939877] do_vfs_ioctl+0x1b1/0x1530 [ 30.943733] SyS_ioctl+0x8f/0xc0 [ 30.947112] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 30.951831] [ 30.953428] Freed by task 3036: [ 30.956693] save_stack_trace+0x16/0x20 [ 30.960634] save_stack+0x43/0xd0 [ 30.964061] kasan_slab_free+0x71/0xc0 [ 30.967917] kfree+0xca/0x250 [ 30.970989] kvfree+0x36/0x60 [ 30.974060] free_netdev+0x2cf/0x360 [ 30.977741] __tun_chr_ioctl+0x2d30/0x3d70 [ 30.981942] tun_chr_ioctl+0x2a/0x40 [ 30.985623] do_vfs_ioctl+0x1b1/0x1530 [ 30.989478] SyS_ioctl+0x8f/0xc0 [ 30.992815] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 30.997536] [ 30.999138] The buggy address belongs to the object at ffff8801ccb602c0 [ 30.999138] which belongs to the cache kmalloc-16384 of size 16384 [ 31.012108] The buggy address is located 13320 bytes inside of [ 31.012108] 16384-byte region [ffff8801ccb602c0, ffff8801ccb642c0) [ 31.024294] The buggy address belongs to the page: [ 31.029198] page:ffffea000732d800 count:1 mapcount:0 mapping:ffff8801ccb602c0 index:0x0 compound_mapcount: 0 [ 31.039145] flags: 0x200000000008100(slab|head) [ 31.043784] raw: 0200000000008100 ffff8801ccb602c0 0000000000000000 0000000100000001 [ 31.051641] raw: ffffea00074f3620 ffffea000732c620 ffff8801dac02200 0000000000000000 [ 31.059486] page dumped because: kasan: bad access detected [ 31.065162] [ 31.066760] Memory state around the buggy address: [ 31.071664] ffff8801ccb63580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.079008] ffff8801ccb63600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.086339] >ffff8801ccb63680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.093665] ^ [ 31.099344] ffff8801ccb63700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.106672] ffff8801ccb63780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.113998] ================================================================== [ 31.121324] Disabling lock debugging due to kernel taint [ 31.126745] Kernel panic - not syncing: panic_on_warn set ... [ 31.126745] [ 31.134069] CPU: 1 PID: 3036 Comm: syzkaller799059 Tainted: G B 4.13.0+ #70 [ 31.142260] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.151575] Call Trace: [ 31.154128] dump_stack+0x194/0x257 [ 31.157722] ? arch_local_irq_restore+0x53/0x53 [ 31.162356] ? vprintk_default+0x28/0x30 [ 31.166386] ? __internal_add_timer+0x1a0/0x2d0 [ 31.171035] panic+0x1e4/0x417 [ 31.174204] ? __warn+0x1d9/0x1d9 [ 31.177625] ? __internal_add_timer+0x275/0x2d0 [ 31.182261] kasan_end_report+0x50/0x50 [ 31.186196] kasan_report+0x137/0x340 [ 31.189961] __asan_report_store8_noabort+0x17/0x20 [ 31.194942] __internal_add_timer+0x275/0x2d0 [ 31.199402] ? calc_wheel_index+0x200/0x200 [ 31.203693] mod_timer+0x622/0x15b0 [ 31.207288] ? mod_timer_pending+0x14e0/0x14e0 [ 31.211835] ? __lock_is_held+0xbc/0x140 [ 31.215875] ? __lock_is_held+0xbc/0x140 [ 31.219904] ? __lockdep_init_map+0xe4/0x650 [ 31.224280] ? lockdep_init_map+0x3d/0x70 [ 31.228393] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.233385] ? init_timer_key+0x126/0x3b0 [ 31.237498] ? try_to_del_timer_sync+0x120/0x120 [ 31.242223] ? round_jiffies_up+0xce/0x100 [ 31.246423] ? __round_jiffies_up_relative+0x150/0x150 [ 31.251680] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 31.256573] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 31.262081] __tun_chr_ioctl+0x1b2c/0x3d70 [ 31.266283] ? tun_select_queue+0x580/0x580 [ 31.270573] ? lock_downgrade+0x990/0x990 [ 31.274700] ? check_same_owner+0x320/0x320 [ 31.278987] ? __handle_mm_fault+0x3840/0x3840 [ 31.283532] ? vmacache_find+0x61/0x270 [ 31.287470] ? tun_chr_compat_ioctl+0x30/0x30 [ 31.291934] tun_chr_ioctl+0x2a/0x40 [ 31.295615] ? tun_chr_ioctl+0x2a/0x40 [ 31.299467] do_vfs_ioctl+0x1b1/0x1530 [ 31.303318] ? ioctl_preallocate+0x2b0/0x2b0 [ 31.307690] ? selinux_capable+0x40/0x40 [ 31.311718] ? putname+0xf3/0x130 [ 31.315135] ? do_sys_open+0x320/0x6d0 [ 31.318988] ? security_file_ioctl+0x7d/0xb0 [ 31.323366] ? security_file_ioctl+0x89/0xb0 [ 31.327742] SyS_ioctl+0x8f/0xc0 [ 31.331074] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 31.335911] RIP: 0033:0x443db9 [ 31.339066] RSP: 002b:00007ffd74f9e968 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 31.346735] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443db9 [ 31.353968] RDX: 0000000020115000 RSI: 00000000400454ca RDI: 0000000000000004 [ 31.361201] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 31.368435] R10: 0000000000000000 R11: 0000000000000206 R12: fdb4a8e95425e60d [ 31.375668] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 31.383232] Dumping ftrace buffer: [ 31.386739] (ftrace buffer empty) [ 31.390412] Kernel Offset: disabled [ 31.394003] Rebooting in 86400 seconds..