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-386-1,10.128.0.58' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 42.296288] ================================================================== [ 42.297383] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 42.298330] Write of size 8 at addr ffff8801d219b500 by task syzkaller637302/2985 [ 42.299377] [ 42.299621] CPU: 1 PID: 2985 Comm: syzkaller637302 Not tainted 4.14.0-rc5+ #51 [ 42.300596] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.301826] Call Trace: [ 42.302188] dump_stack+0x194/0x257 [ 42.302685] ? arch_local_irq_restore+0x53/0x53 [ 42.303311] ? show_regs_print_info+0x65/0x65 [ 42.303953] ? __kernel_text_address+0xd/0x40 [ 42.304562] ? __internal_add_timer+0x275/0x2d0 [ 42.305194] print_address_description+0x73/0x250 [ 42.305864] ? __internal_add_timer+0x275/0x2d0 [ 42.306498] kasan_report+0x25b/0x340 [ 42.307020] __asan_report_store8_noabort+0x17/0x20 [ 42.307715] __internal_add_timer+0x275/0x2d0 [ 42.308323] ? calc_wheel_index+0x200/0x200 [ 42.308931] mod_timer+0x622/0x15b0 [ 42.309440] ? mod_timer_pending+0x14e0/0x14e0 [ 42.310079] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 42.310748] ? trace_hardirqs_on+0xd/0x10 [ 42.311310] ? _crng_backtrack_protect+0xd9/0x130 [ 42.311966] ? __lock_is_held+0xb6/0x140 [ 42.312519] ? __lockdep_init_map+0xe4/0x650 [ 42.313116] ? lockdep_init_map+0x9/0x10 [ 42.313667] ? init_timer_key+0x126/0x3b0 [ 42.314235] ? try_to_del_timer_sync+0x120/0x120 [ 42.314896] ? round_jiffies_up+0xce/0x100 [ 42.315469] ? __round_jiffies_up_relative+0x150/0x150 [ 42.316193] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 42.317026] __tun_chr_ioctl+0x1b17/0x3d20 [ 42.321240] ? tun_chr_read_iter+0x1e0/0x1e0 [ 42.325627] ? find_held_lock+0x35/0x1d0 [ 42.329689] ? __might_sleep+0x95/0x190 [ 42.333641] ? handle_mm_fault+0x248/0x8d0 [ 42.337860] ? selinux_file_ioctl+0x444/0x690 [ 42.342325] ? __fget_light+0x297/0x380 [ 42.346275] ? selinux_capable+0x40/0x40 [ 42.350318] ? handle_mm_fault+0x410/0x8d0 [ 42.354541] tun_chr_compat_ioctl+0x29/0x30 [ 42.358845] ? tun_chr_compat_ioctl+0x29/0x30 [ 42.363320] compat_SyS_ioctl+0x1d7/0x3290 [ 42.367530] ? up_read+0x1a/0x40 [ 42.370877] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 42.375265] ? do_ioctl+0x60/0x60 [ 42.378697] ? do_fast_syscall_32+0x158/0xf05 [ 42.383172] ? do_ioctl+0x60/0x60 [ 42.386601] do_fast_syscall_32+0x3f2/0xf05 [ 42.390906] ? do_int80_syscall_32+0x940/0x940 [ 42.395462] ? kasan_check_read+0x11/0x20 [ 42.399585] ? syscall_return_slowpath+0x510/0x510 [ 42.404492] ? SyS_rt_sigaction+0x94/0x1b0 [ 42.408721] ? SyS_sigprocmask+0x4b0/0x4b0 [ 42.412938] ? SyS_read+0x184/0x220 [ 42.416547] ? retint_user+0x18/0x20 [ 42.420244] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.425066] entry_SYSENTER_compat+0x51/0x60 [ 42.429447] RIP: 0023:0xf7f56c79 [ 42.432786] RSP: 002b:00000000ff857dec EFLAGS: 00000286 ORIG_RAX: 0000000000000036 [ 42.440470] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000400454ca [ 42.447716] RDX: 0000000020511fd8 RSI: 00000000080ef00c RDI: 000000000000003f [ 42.454958] RBP: 0000000000001000 R08: 0000000000000000 R09: 0000000000000000 [ 42.462198] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 42.469442] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 42.476709] [ 42.478305] Allocated by task 2985: [ 42.481902] save_stack_trace+0x16/0x20 [ 42.485843] save_stack+0x43/0xd0 [ 42.489263] kasan_kmalloc+0xad/0xe0 [ 42.492943] __kmalloc_node+0x47/0x70 [ 42.496711] kvmalloc_node+0x64/0xd0 [ 42.500391] alloc_netdev_mqs+0x16e/0xed0 [ 42.504507] __tun_chr_ioctl+0x12b2/0x3d20 [ 42.508706] tun_chr_compat_ioctl+0x29/0x30 [ 42.512994] compat_SyS_ioctl+0x1d7/0x3290 [ 42.517197] do_fast_syscall_32+0x3f2/0xf05 [ 42.521483] entry_SYSENTER_compat+0x51/0x60 [ 42.525853] [ 42.527447] Freed by task 2985: [ 42.530692] save_stack_trace+0x16/0x20 [ 42.534631] save_stack+0x43/0xd0 [ 42.538051] kasan_slab_free+0x71/0xc0 [ 42.541904] kfree+0xca/0x250 [ 42.544973] kvfree+0x36/0x60 [ 42.548043] free_netdev+0x2cf/0x360 [ 42.551720] __tun_chr_ioctl+0x2cea/0x3d20 [ 42.555917] tun_chr_compat_ioctl+0x29/0x30 [ 42.560203] compat_SyS_ioctl+0x1d7/0x3290 [ 42.564403] do_fast_syscall_32+0x3f2/0xf05 [ 42.568690] entry_SYSENTER_compat+0x51/0x60 [ 42.573059] [ 42.574652] The buggy address belongs to the object at ffff8801d21981c0 [ 42.574652] which belongs to the cache kmalloc-16384 of size 16384 [ 42.587622] The buggy address is located 13120 bytes inside of [ 42.587622] 16384-byte region [ffff8801d21981c0, ffff8801d219c1c0) [ 42.599805] The buggy address belongs to the page: [ 42.604700] page:ffffea0007486600 count:1 mapcount:0 mapping:ffff8801d21981c0 index:0x0 compound_mapcount: 0 [ 42.614636] flags: 0x200000000008100(slab|head) [ 42.619269] raw: 0200000000008100 ffff8801d21981c0 0000000000000000 0000000100000001 [ 42.627115] raw: ffffea0007653e20 ffffea0007029220 ffff8801dac02200 0000000000000000 [ 42.634962] page dumped because: kasan: bad access detected [ 42.640636] [ 42.642230] Memory state around the buggy address: [ 42.647124] ffff8801d219b400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.654447] ffff8801d219b480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.661769] >ffff8801d219b500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.669091] ^ [ 42.672425] ffff8801d219b580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.679746] ffff8801d219b600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.687068] ================================================================== [ 42.694392] Disabling lock debugging due to kernel taint [ 42.699805] Kernel panic - not syncing: panic_on_warn set ... [ 42.699805] [ 42.707130] CPU: 1 PID: 2985 Comm: syzkaller637302 Tainted: G B 4.14.0-rc5+ #51 [ 42.715665] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.724983] Call Trace: [ 42.727542] dump_stack+0x194/0x257 [ 42.731136] ? arch_local_irq_restore+0x53/0x53 [ 42.735770] ? kasan_end_report+0x32/0x50 [ 42.739882] ? lock_downgrade+0x990/0x990 [ 42.743995] ? __internal_add_timer+0x1f0/0x2d0 [ 42.748632] panic+0x1e4/0x417 [ 42.751788] ? __warn+0x1d9/0x1d9 [ 42.755210] ? __internal_add_timer+0x275/0x2d0 [ 42.759842] kasan_end_report+0x50/0x50 [ 42.763779] kasan_report+0x144/0x340 [ 42.767546] __asan_report_store8_noabort+0x17/0x20 [ 42.772526] __internal_add_timer+0x275/0x2d0 [ 42.776985] ? calc_wheel_index+0x200/0x200 [ 42.781275] mod_timer+0x622/0x15b0 [ 42.784869] ? mod_timer_pending+0x14e0/0x14e0 [ 42.789414] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 42.794397] ? trace_hardirqs_on+0xd/0x10 [ 42.798511] ? _crng_backtrack_protect+0xd9/0x130 [ 42.803323] ? __lock_is_held+0xb6/0x140 [ 42.807351] ? __lockdep_init_map+0xe4/0x650 [ 42.811723] ? lockdep_init_map+0x9/0x10 [ 42.815749] ? init_timer_key+0x126/0x3b0 [ 42.819862] ? try_to_del_timer_sync+0x120/0x120 [ 42.824584] ? round_jiffies_up+0xce/0x100 [ 42.828783] ? __round_jiffies_up_relative+0x150/0x150 [ 42.834024] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 42.838924] __tun_chr_ioctl+0x1b17/0x3d20 [ 42.843129] ? tun_chr_read_iter+0x1e0/0x1e0 [ 42.847503] ? find_held_lock+0x35/0x1d0 [ 42.851533] ? __might_sleep+0x95/0x190 [ 42.855471] ? handle_mm_fault+0x248/0x8d0 [ 42.859673] ? selinux_file_ioctl+0x444/0x690 [ 42.864132] ? __fget_light+0x297/0x380 [ 42.868072] ? selinux_capable+0x40/0x40 [ 42.872101] ? handle_mm_fault+0x410/0x8d0 [ 42.876303] tun_chr_compat_ioctl+0x29/0x30 [ 42.880588] ? tun_chr_compat_ioctl+0x29/0x30 [ 42.885049] compat_SyS_ioctl+0x1d7/0x3290 [ 42.889246] ? up_read+0x1a/0x40 [ 42.892577] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 42.896950] ? do_ioctl+0x60/0x60 [ 42.900369] ? do_fast_syscall_32+0x158/0xf05 [ 42.904831] ? do_ioctl+0x60/0x60 [ 42.908251] do_fast_syscall_32+0x3f2/0xf05 [ 42.912540] ? do_int80_syscall_32+0x940/0x940 [ 42.917087] ? kasan_check_read+0x11/0x20 [ 42.921204] ? syscall_return_slowpath+0x510/0x510 [ 42.926097] ? SyS_rt_sigaction+0x94/0x1b0 [ 42.930299] ? SyS_sigprocmask+0x4b0/0x4b0 [ 42.934498] ? SyS_read+0x184/0x220 [ 42.938268] ? retint_user+0x18/0x20 [ 42.941948] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.946756] entry_SYSENTER_compat+0x51/0x60 [ 42.951128] RIP: 0023:0xf7f56c79 [ 42.954456] RSP: 002b:00000000ff857dec EFLAGS: 00000286 ORIG_RAX: 0000000000000036 [ 42.962135] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000400454ca [ 42.969369] RDX: 0000000020511fd8 RSI: 00000000080ef00c RDI: 000000000000003f [ 42.976603] RBP: 0000000000001000 R08: 0000000000000000 R09: 0000000000000000 [ 42.983847] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 42.991093] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 42.998372] Dumping ftrace buffer: [ 43.001878] (ftrace buffer empty) [ 43.005555] Kernel Offset: disabled [ 43.009149] Rebooting in 86400 seconds..