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-386-0,10.128.15.233' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 43.662399] ================================================================== [ 43.663601] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 43.664591] Write of size 8 at addr ffff8801d1eb3600 by task syzkaller453449/2985 [ 43.665626] [ 43.665894] CPU: 1 PID: 2985 Comm: syzkaller453449 Not tainted 4.14.0-rc5+ #51 [ 43.666876] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.668161] Call Trace: [ 43.668519] dump_stack+0x194/0x257 [ 43.669032] ? arch_local_irq_restore+0x53/0x53 [ 43.669674] ? show_regs_print_info+0x65/0x65 [ 43.670277] ? __kernel_text_address+0xd/0x40 [ 43.670878] ? __internal_add_timer+0x275/0x2d0 [ 43.671531] print_address_description+0x73/0x250 [ 43.672186] ? __internal_add_timer+0x275/0x2d0 [ 43.672821] kasan_report+0x25b/0x340 [ 43.673361] __asan_report_store8_noabort+0x17/0x20 [ 43.674031] __internal_add_timer+0x275/0x2d0 [ 43.674634] ? calc_wheel_index+0x200/0x200 [ 43.675221] mod_timer+0x622/0x15b0 [ 43.675720] ? mod_timer_pending+0x14e0/0x14e0 [ 43.676467] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.677136] ? trace_hardirqs_on+0xd/0x10 [ 43.677697] ? _crng_backtrack_protect+0xd9/0x130 [ 43.678364] ? __lock_is_held+0xb6/0x140 [ 43.678914] ? __lockdep_init_map+0xe4/0x650 [ 43.679507] ? lockdep_init_map+0x9/0x10 [ 43.680050] ? init_timer_key+0x126/0x3b0 [ 43.680608] ? try_to_del_timer_sync+0x120/0x120 [ 43.681261] ? round_jiffies_up+0xce/0x100 [ 43.681827] ? __round_jiffies_up_relative+0x150/0x150 [ 43.682528] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 43.687235] __tun_chr_ioctl+0x1b17/0x3d20 [ 43.691449] ? tun_chr_read_iter+0x1e0/0x1e0 [ 43.695827] ? find_held_lock+0x35/0x1d0 [ 43.699866] ? __might_sleep+0x95/0x190 [ 43.703811] ? handle_mm_fault+0x248/0x8d0 [ 43.708026] ? selinux_file_ioctl+0x444/0x690 [ 43.712488] ? __fget_light+0x297/0x380 [ 43.716431] ? selinux_capable+0x40/0x40 [ 43.720469] ? handle_mm_fault+0x410/0x8d0 [ 43.724680] tun_chr_compat_ioctl+0x29/0x30 [ 43.728968] ? tun_chr_compat_ioctl+0x29/0x30 [ 43.733433] compat_SyS_ioctl+0x1d7/0x3290 [ 43.737635] ? up_read+0x1a/0x40 [ 43.740969] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 43.745347] ? do_ioctl+0x60/0x60 [ 43.748770] ? do_fast_syscall_32+0x158/0xf05 [ 43.753239] ? do_ioctl+0x60/0x60 [ 43.756660] do_fast_syscall_32+0x3f2/0xf05 [ 43.760954] ? do_int80_syscall_32+0x940/0x940 [ 43.765505] ? kasan_check_read+0x11/0x20 [ 43.769621] ? syscall_return_slowpath+0x510/0x510 [ 43.774520] ? SyS_rt_sigaction+0x94/0x1b0 [ 43.778723] ? SyS_sigprocmask+0x4b0/0x4b0 [ 43.782928] ? SyS_read+0x184/0x220 [ 43.786525] ? retint_user+0x18/0x20 [ 43.790214] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 43.795031] entry_SYSENTER_compat+0x51/0x60 [ 43.799407] RIP: 0023:0xf7f2ac79 [ 43.802736] RSP: 002b:00000000ff96d4dc EFLAGS: 00000286 ORIG_RAX: 0000000000000036 [ 43.810412] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000400454ca [ 43.817650] RDX: 0000000020fbcfd8 RSI: 00000000080ef00c RDI: 000000000000003f [ 43.824886] RBP: 0000000000001000 R08: 0000000000000000 R09: 0000000000000000 [ 43.832125] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 43.839361] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 43.846613] [ 43.848208] Allocated by task 2985: [ 43.851804] save_stack_trace+0x16/0x20 [ 43.855747] save_stack+0x43/0xd0 [ 43.859166] kasan_kmalloc+0xad/0xe0 [ 43.862847] __kmalloc_node+0x47/0x70 [ 43.866615] kvmalloc_node+0x64/0xd0 [ 43.870296] alloc_netdev_mqs+0x16e/0xed0 [ 43.874408] __tun_chr_ioctl+0x12b2/0x3d20 [ 43.878607] tun_chr_compat_ioctl+0x29/0x30 [ 43.882895] compat_SyS_ioctl+0x1d7/0x3290 [ 43.887096] do_fast_syscall_32+0x3f2/0xf05 [ 43.891382] entry_SYSENTER_compat+0x51/0x60 [ 43.895752] [ 43.897346] Freed by task 2985: [ 43.900590] save_stack_trace+0x16/0x20 [ 43.904530] save_stack+0x43/0xd0 [ 43.907947] kasan_slab_free+0x71/0xc0 [ 43.911798] kfree+0xca/0x250 [ 43.914867] kvfree+0x36/0x60 [ 43.917937] free_netdev+0x2cf/0x360 [ 43.921613] __tun_chr_ioctl+0x2cea/0x3d20 [ 43.925810] tun_chr_compat_ioctl+0x29/0x30 [ 43.930099] compat_SyS_ioctl+0x1d7/0x3290 [ 43.934297] do_fast_syscall_32+0x3f2/0xf05 [ 43.938583] entry_SYSENTER_compat+0x51/0x60 [ 43.942953] [ 43.944548] The buggy address belongs to the object at ffff8801d1eb02c0 [ 43.944548] which belongs to the cache kmalloc-16384 of size 16384 [ 43.957514] The buggy address is located 13120 bytes inside of [ 43.957514] 16384-byte region [ffff8801d1eb02c0, ffff8801d1eb42c0) [ 43.969701] The buggy address belongs to the page: [ 43.974598] page:ffffea000747ac00 count:1 mapcount:0 mapping:ffff8801d1eb02c0 index:0x0 compound_mapcount: 0 [ 43.984534] flags: 0x200000000008100(slab|head) [ 43.989171] raw: 0200000000008100 ffff8801d1eb02c0 0000000000000000 0000000100000001 [ 43.997018] raw: ffffea0007667820 ffffea000748e620 ffff8801dac02200 0000000000000000 [ 44.004864] page dumped because: kasan: bad access detected [ 44.010538] [ 44.012130] Memory state around the buggy address: [ 44.017026] ffff8801d1eb3500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.024350] ffff8801d1eb3580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.031675] >ffff8801d1eb3600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.039006] ^ [ 44.042339] ffff8801d1eb3680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.049664] ffff8801d1eb3700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.056986] ================================================================== [ 44.064309] Disabling lock debugging due to kernel taint [ 44.069721] Kernel panic - not syncing: panic_on_warn set ... [ 44.069721] [ 44.077047] CPU: 1 PID: 2985 Comm: syzkaller453449 Tainted: G B 4.14.0-rc5+ #51 [ 44.085587] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.094906] Call Trace: [ 44.097467] dump_stack+0x194/0x257 [ 44.101060] ? arch_local_irq_restore+0x53/0x53 [ 44.105695] ? kasan_end_report+0x32/0x50 [ 44.109811] ? lock_downgrade+0x990/0x990 [ 44.113928] ? __internal_add_timer+0x1f0/0x2d0 [ 44.118562] panic+0x1e4/0x417 [ 44.121720] ? __warn+0x1d9/0x1d9 [ 44.125144] ? __internal_add_timer+0x275/0x2d0 [ 44.129864] kasan_end_report+0x50/0x50 [ 44.133806] kasan_report+0x144/0x340 [ 44.137575] __asan_report_store8_noabort+0x17/0x20 [ 44.142556] __internal_add_timer+0x275/0x2d0 [ 44.147017] ? calc_wheel_index+0x200/0x200 [ 44.151308] mod_timer+0x622/0x15b0 [ 44.154904] ? mod_timer_pending+0x14e0/0x14e0 [ 44.159456] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 44.164439] ? trace_hardirqs_on+0xd/0x10 [ 44.168556] ? _crng_backtrack_protect+0xd9/0x130 [ 44.173365] ? __lock_is_held+0xb6/0x140 [ 44.177398] ? __lockdep_init_map+0xe4/0x650 [ 44.181773] ? lockdep_init_map+0x9/0x10 [ 44.185799] ? init_timer_key+0x126/0x3b0 [ 44.189916] ? try_to_del_timer_sync+0x120/0x120 [ 44.194639] ? round_jiffies_up+0xce/0x100 [ 44.198836] ? __round_jiffies_up_relative+0x150/0x150 [ 44.204078] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 44.208976] __tun_chr_ioctl+0x1b17/0x3d20 [ 44.213181] ? tun_chr_read_iter+0x1e0/0x1e0 [ 44.217553] ? find_held_lock+0x35/0x1d0 [ 44.221584] ? __might_sleep+0x95/0x190 [ 44.225523] ? handle_mm_fault+0x248/0x8d0 [ 44.229729] ? selinux_file_ioctl+0x444/0x690 [ 44.234188] ? __fget_light+0x297/0x380 [ 44.238127] ? selinux_capable+0x40/0x40 [ 44.242159] ? handle_mm_fault+0x410/0x8d0 [ 44.246369] tun_chr_compat_ioctl+0x29/0x30 [ 44.250654] ? tun_chr_compat_ioctl+0x29/0x30 [ 44.255119] compat_SyS_ioctl+0x1d7/0x3290 [ 44.259321] ? up_read+0x1a/0x40 [ 44.262653] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 44.267028] ? do_ioctl+0x60/0x60 [ 44.270447] ? do_fast_syscall_32+0x158/0xf05 [ 44.274914] ? do_ioctl+0x60/0x60 [ 44.278336] do_fast_syscall_32+0x3f2/0xf05 [ 44.282628] ? do_int80_syscall_32+0x940/0x940 [ 44.287174] ? kasan_check_read+0x11/0x20 [ 44.291287] ? syscall_return_slowpath+0x510/0x510 [ 44.296183] ? SyS_rt_sigaction+0x94/0x1b0 [ 44.300383] ? SyS_sigprocmask+0x4b0/0x4b0 [ 44.304582] ? SyS_read+0x184/0x220 [ 44.308179] ? retint_user+0x18/0x20 [ 44.311858] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 44.316669] entry_SYSENTER_compat+0x51/0x60 [ 44.321043] RIP: 0023:0xf7f2ac79 [ 44.324373] RSP: 002b:00000000ff96d4dc EFLAGS: 00000286 ORIG_RAX: 0000000000000036 [ 44.332044] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000400454ca [ 44.339280] RDX: 0000000020fbcfd8 RSI: 00000000080ef00c RDI: 000000000000003f [ 44.346514] RBP: 0000000000001000 R08: 0000000000000000 R09: 0000000000000000 [ 44.353752] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 44.360985] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 44.368265] Dumping ftrace buffer: [ 44.371771] (ftrace buffer empty) [ 44.375448] Kernel Offset: disabled [ 44.379043] Rebooting in 86400 seconds..