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-9,10.128.15.197' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 27.516280] ================================================================== [ 27.517478] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 27.518414] Write of size 8 at addr ffff8801d219b500 by task syzkaller437827/2989 [ 27.519425] [ 27.519671] CPU: 1 PID: 2989 Comm: syzkaller437827 Not tainted 4.14.0-rc5+ #141 [ 27.520645] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.521864] Call Trace: [ 27.522219] dump_stack+0x194/0x257 [ 27.522711] ? arch_local_irq_restore+0x53/0x53 [ 27.523332] ? show_regs_print_info+0x65/0x65 [ 27.523934] ? __kernel_text_address+0xd/0x40 [ 27.524532] ? __internal_add_timer+0x275/0x2d0 [ 27.525157] print_address_description+0x73/0x250 [ 27.525801] ? __internal_add_timer+0x275/0x2d0 [ 27.526423] kasan_report+0x25b/0x340 [ 27.526938] __asan_report_store8_noabort+0x17/0x20 [ 27.527606] __internal_add_timer+0x275/0x2d0 [ 27.528206] ? calc_wheel_index+0x200/0x200 [ 27.528853] mod_timer+0x622/0x15b0 [ 27.529399] ? mod_timer_pending+0x14e0/0x14e0 [ 27.530016] ? __lock_is_held+0xb6/0x140 [ 27.530573] ? __lock_is_held+0xb6/0x140 [ 27.531164] ? __lockdep_init_map+0xe4/0x650 [ 27.531805] ? lockdep_init_map+0x9/0x10 [ 27.532354] ? init_timer_key+0x126/0x3b0 [ 27.532949] ? try_to_del_timer_sync+0x120/0x120 [ 27.533614] ? round_jiffies_up+0xce/0x100 [ 27.534183] ? __round_jiffies_up_relative+0x150/0x150 [ 27.534899] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 27.535557] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 27.536300] __tun_chr_ioctl+0x1b17/0x3d20 [ 27.536912] ? tun_chr_read_iter+0x1e0/0x1e0 [ 27.541288] ? lock_release+0x51c/0xa40 [ 27.545232] ? __do_page_fault+0x64c/0xd60 [ 27.549433] ? lock_downgrade+0x990/0x990 [ 27.553555] ? handle_mm_fault+0x410/0x8d0 [ 27.557771] ? check_same_owner+0x320/0x320 [ 27.562056] ? up_read+0x1a/0x40 [ 27.565388] ? __do_page_fault+0x3d6/0xd60 [ 27.569599] ? tun_chr_compat_ioctl+0x30/0x30 [ 27.574066] tun_chr_ioctl+0x2a/0x40 [ 27.577760] ? tun_chr_ioctl+0x2a/0x40 [ 27.581617] do_vfs_ioctl+0x1b1/0x1520 [ 27.585476] ? ioctl_preallocate+0x2b0/0x2b0 [ 27.589860] ? selinux_capable+0x40/0x40 [ 27.593893] ? putname+0xf3/0x130 [ 27.597320] ? do_sys_open+0x320/0x6d0 [ 27.601191] ? security_file_ioctl+0x89/0xb0 [ 27.605574] SyS_ioctl+0x8f/0xc0 [ 27.608911] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 27.613631] RIP: 0033:0x443db9 [ 27.616786] RSP: 002b:00007ffd60175618 EFLAGS: 00000207 ORIG_RAX: 0000000000000010 [ 27.624461] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443db9 [ 27.631696] RDX: 0000000020136fd8 RSI: 00000000400454ca RDI: 0000000000000006 [ 27.638932] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 27.646167] R10: 0000000000000000 R11: 0000000000000207 R12: 0000000000401aa0 [ 27.653407] R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000 [ 27.660667] [ 27.662264] Allocated by task 2989: [ 27.665857] save_stack_trace+0x16/0x20 [ 27.669799] save_stack+0x43/0xd0 [ 27.673219] kasan_kmalloc+0xad/0xe0 [ 27.676902] __kmalloc_node+0x47/0x70 [ 27.680667] kvmalloc_node+0x64/0xd0 [ 27.684347] alloc_netdev_mqs+0x16e/0xed0 [ 27.688458] __tun_chr_ioctl+0x12b2/0x3d20 [ 27.692657] tun_chr_ioctl+0x2a/0x40 [ 27.696336] do_vfs_ioctl+0x1b1/0x1520 [ 27.700187] SyS_ioctl+0x8f/0xc0 [ 27.703520] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 27.708238] [ 27.709831] Freed by task 2989: [ 27.713074] save_stack_trace+0x16/0x20 [ 27.717012] save_stack+0x43/0xd0 [ 27.720429] kasan_slab_free+0x71/0xc0 [ 27.724280] kfree+0xca/0x250 [ 27.727349] kvfree+0x36/0x60 [ 27.730418] free_netdev+0x2cf/0x360 [ 27.734094] __tun_chr_ioctl+0x2cea/0x3d20 [ 27.738294] tun_chr_ioctl+0x2a/0x40 [ 27.741974] do_vfs_ioctl+0x1b1/0x1520 [ 27.745828] SyS_ioctl+0x8f/0xc0 [ 27.749167] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 27.753901] [ 27.755495] The buggy address belongs to the object at ffff8801d21981c0 [ 27.755495] which belongs to the cache kmalloc-16384 of size 16384 [ 27.768464] The buggy address is located 13120 bytes inside of [ 27.768464] 16384-byte region [ffff8801d21981c0, ffff8801d219c1c0) [ 27.780650] The buggy address belongs to the page: [ 27.785554] page:ffffea0007486600 count:1 mapcount:0 mapping:ffff8801d21981c0 index:0x0 compound_mapcount: 0 [ 27.795495] flags: 0x200000000008100(slab|head) [ 27.800136] raw: 0200000000008100 ffff8801d21981c0 0000000000000000 0000000100000001 [ 27.807984] raw: ffffea000750d620 ffffea0007051820 ffff8801dac02200 0000000000000000 [ 27.815826] page dumped because: kasan: bad access detected [ 27.821498] [ 27.823088] Memory state around the buggy address: [ 27.827982] ffff8801d219b400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.835303] ffff8801d219b480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.842624] >ffff8801d219b500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.849943] ^ [ 27.853271] ffff8801d219b580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.860600] ffff8801d219b600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 27.867922] ================================================================== [ 27.875245] Disabling lock debugging due to kernel taint [ 27.880657] Kernel panic - not syncing: panic_on_warn set ... [ 27.880657] [ 27.887981] CPU: 1 PID: 2989 Comm: syzkaller437827 Tainted: G B 4.14.0-rc5+ #141 [ 27.896603] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.905920] Call Trace: [ 27.908477] dump_stack+0x194/0x257 [ 27.912073] ? arch_local_irq_restore+0x53/0x53 [ 27.916706] ? kasan_end_report+0x32/0x50 [ 27.920818] ? lock_downgrade+0x990/0x990 [ 27.924936] ? __internal_add_timer+0x1f0/0x2d0 [ 27.929568] panic+0x1e4/0x417 [ 27.932724] ? __warn+0x1d9/0x1d9 [ 27.936150] ? __internal_add_timer+0x275/0x2d0 [ 27.940783] kasan_end_report+0x50/0x50 [ 27.944719] kasan_report+0x144/0x340 [ 27.948486] __asan_report_store8_noabort+0x17/0x20 [ 27.953465] __internal_add_timer+0x275/0x2d0 [ 27.957924] ? calc_wheel_index+0x200/0x200 [ 27.962213] mod_timer+0x622/0x15b0 [ 27.965806] ? mod_timer_pending+0x14e0/0x14e0 [ 27.970360] ? __lock_is_held+0xb6/0x140 [ 27.974393] ? __lock_is_held+0xb6/0x140 [ 27.978422] ? __lockdep_init_map+0xe4/0x650 [ 27.982794] ? lockdep_init_map+0x9/0x10 [ 27.986819] ? init_timer_key+0x126/0x3b0 [ 27.990931] ? try_to_del_timer_sync+0x120/0x120 [ 27.995651] ? round_jiffies_up+0xce/0x100 [ 27.999850] ? __round_jiffies_up_relative+0x150/0x150 [ 28.005088] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 28.009983] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 28.015488] __tun_chr_ioctl+0x1b17/0x3d20 [ 28.019692] ? tun_chr_read_iter+0x1e0/0x1e0 [ 28.024066] ? lock_release+0x51c/0xa40 [ 28.028006] ? __do_page_fault+0x64c/0xd60 [ 28.032203] ? lock_downgrade+0x990/0x990 [ 28.036318] ? handle_mm_fault+0x410/0x8d0 [ 28.040522] ? check_same_owner+0x320/0x320 [ 28.044807] ? up_read+0x1a/0x40 [ 28.048140] ? __do_page_fault+0x3d6/0xd60 [ 28.052341] ? tun_chr_compat_ioctl+0x30/0x30 [ 28.056797] tun_chr_ioctl+0x2a/0x40 [ 28.060472] ? tun_chr_ioctl+0x2a/0x40 [ 28.064325] do_vfs_ioctl+0x1b1/0x1520 [ 28.068179] ? ioctl_preallocate+0x2b0/0x2b0 [ 28.072554] ? selinux_capable+0x40/0x40 [ 28.076580] ? putname+0xf3/0x130 [ 28.080009] ? do_sys_open+0x320/0x6d0 [ 28.083878] ? security_file_ioctl+0x89/0xb0 [ 28.088251] SyS_ioctl+0x8f/0xc0 [ 28.091584] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 28.096300] RIP: 0033:0x443db9 [ 28.099454] RSP: 002b:00007ffd60175618 EFLAGS: 00000207 ORIG_RAX: 0000000000000010 [ 28.107126] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443db9 [ 28.114361] RDX: 0000000020136fd8 RSI: 00000000400454ca RDI: 0000000000000006 [ 28.121595] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 28.128828] R10: 0000000000000000 R11: 0000000000000207 R12: 0000000000401aa0 [ 28.136060] R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000 [ 28.143338] Dumping ftrace buffer: [ 28.146842] (ftrace buffer empty) [ 28.150516] Kernel Offset: disabled [ 28.154107] Rebooting in 86400 seconds..