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-386-3,10.128.15.204' (ECDSA) to the list of known hosts. executing program executing program executing program syzkaller login: [ 76.962481] ================================================================== [ 76.963649] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 76.964628] Write of size 8 at addr ffff8801c0ecb640 by task syzkaller154453/2980 [ 76.965623] [ 76.965872] CPU: 0 PID: 2980 Comm: syzkaller154453 Not tainted 4.14.0-rc5+ #47 [ 76.966851] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 76.968081] Call Trace: [ 76.968440] dump_stack+0x194/0x257 [ 76.968949] ? arch_local_irq_restore+0x53/0x53 [ 76.969676] ? show_regs_print_info+0x65/0x65 [ 76.970328] ? __kernel_text_address+0xd/0x40 [ 76.970927] ? __internal_add_timer+0x275/0x2d0 [ 76.971550] print_address_description+0x73/0x250 [ 76.972211] ? __internal_add_timer+0x275/0x2d0 [ 76.972870] kasan_report+0x25b/0x340 [ 76.973395] __asan_report_store8_noabort+0x17/0x20 [ 76.974061] __internal_add_timer+0x275/0x2d0 [ 76.974664] ? calc_wheel_index+0x200/0x200 [ 76.975254] mod_timer+0x622/0x15b0 [ 76.975751] ? mod_timer_pending+0x14e0/0x14e0 [ 76.976366] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 76.977144] ? trace_hardirqs_on+0xd/0x10 [ 76.977707] ? _crng_backtrack_protect+0xd9/0x130 [ 76.978391] ? __lock_is_held+0xb6/0x140 [ 76.978964] ? __lockdep_init_map+0xe4/0x650 [ 76.979814] ? lockdep_init_map+0x9/0x10 [ 76.980359] ? init_timer_key+0x126/0x3b0 [ 76.980929] ? try_to_del_timer_sync+0x120/0x120 [ 76.981564] ? round_jiffies_up+0xce/0x100 [ 76.982131] ? __round_jiffies_up_relative+0x150/0x150 [ 76.982833] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 76.987739] __tun_chr_ioctl+0x1b17/0x3d20 [ 76.991949] ? tun_chr_read_iter+0x1e0/0x1e0 [ 76.996327] ? find_held_lock+0x35/0x1d0 [ 77.000365] ? __might_sleep+0x95/0x190 [ 77.004303] ? handle_mm_fault+0x248/0x8d0 [ 77.008511] ? selinux_file_ioctl+0x444/0x690 [ 77.012976] ? __fget_light+0x297/0x380 [ 77.016920] ? selinux_capable+0x40/0x40 [ 77.020956] ? handle_mm_fault+0x410/0x8d0 [ 77.025165] tun_chr_compat_ioctl+0x29/0x30 [ 77.029455] ? tun_chr_compat_ioctl+0x29/0x30 [ 77.033923] compat_SyS_ioctl+0x1d7/0x3290 [ 77.038124] ? up_read+0x1a/0x40 [ 77.041458] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 77.045837] ? do_ioctl+0x60/0x60 [ 77.049262] ? do_fast_syscall_32+0x158/0xf05 [ 77.053728] ? do_ioctl+0x60/0x60 [ 77.057151] do_fast_syscall_32+0x3f2/0xf05 [ 77.061448] ? do_int80_syscall_32+0x940/0x940 [ 77.066000] ? kasan_check_read+0x11/0x20 [ 77.070117] ? syscall_return_slowpath+0x510/0x510 [ 77.075020] ? SyS_rt_sigaction+0x94/0x1b0 [ 77.079222] ? SyS_sigprocmask+0x4b0/0x4b0 [ 77.083424] ? SyS_read+0x184/0x220 [ 77.087021] ? retint_user+0x18/0x20 [ 77.090709] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 77.095526] entry_SYSENTER_compat+0x51/0x60 [ 77.099898] RIP: 0023:0xf7feec79 [ 77.103228] RSP: 002b:00000000ffc5bb6c EFLAGS: 00000282 ORIG_RAX: 0000000000000036 [ 77.110905] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000400454ca [ 77.118141] RDX: 0000000020927fd8 RSI: 00000000080ef00c RDI: 000000000000003f [ 77.125381] RBP: 0000000000001000 R08: 0000000000000000 R09: 0000000000000000 [ 77.132620] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 77.139860] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 77.147116] [ 77.148713] Allocated by task 2980: [ 77.152313] save_stack_trace+0x16/0x20 [ 77.156253] save_stack+0x43/0xd0 [ 77.159671] kasan_kmalloc+0xad/0xe0 [ 77.163364] __kmalloc_node+0x47/0x70 [ 77.167150] kvmalloc_node+0x64/0xd0 [ 77.170837] alloc_netdev_mqs+0x16e/0xed0 [ 77.174951] __tun_chr_ioctl+0x12b2/0x3d20 [ 77.179150] tun_chr_compat_ioctl+0x29/0x30 [ 77.183440] compat_SyS_ioctl+0x1d7/0x3290 [ 77.187640] do_fast_syscall_32+0x3f2/0xf05 [ 77.191926] entry_SYSENTER_compat+0x51/0x60 [ 77.196296] [ 77.197888] Freed by task 2980: [ 77.201132] save_stack_trace+0x16/0x20 [ 77.205076] save_stack+0x43/0xd0 [ 77.208499] kasan_slab_free+0x71/0xc0 [ 77.212352] kfree+0xca/0x250 [ 77.215423] kvfree+0x36/0x60 [ 77.218494] free_netdev+0x2cf/0x360 [ 77.222173] __tun_chr_ioctl+0x2cea/0x3d20 [ 77.226371] tun_chr_compat_ioctl+0x29/0x30 [ 77.230660] compat_SyS_ioctl+0x1d7/0x3290 [ 77.234876] do_fast_syscall_32+0x3f2/0xf05 [ 77.239313] entry_SYSENTER_compat+0x51/0x60 [ 77.243708] [ 77.245303] The buggy address belongs to the object at ffff8801c0ec8300 [ 77.245303] which belongs to the cache kmalloc-16384 of size 16384 [ 77.258270] The buggy address is located 13120 bytes inside of [ 77.258270] 16384-byte region [ffff8801c0ec8300, ffff8801c0ecc300) [ 77.270454] The buggy address belongs to the page: [ 77.275351] page:ffffea000703b200 count:1 mapcount:0 mapping:ffff8801c0ec8300 index:0x0 compound_mapcount: 0 [ 77.285285] flags: 0x200000000008100(slab|head) [ 77.289919] raw: 0200000000008100 ffff8801c0ec8300 0000000000000000 0000000100000001 [ 77.297765] raw: ffffea000748d820 ffffea000748be20 ffff8801dac02200 0000000000000000 [ 77.305610] page dumped because: kasan: bad access detected [ 77.311282] [ 77.312873] Memory state around the buggy address: [ 77.317768] ffff8801c0ecb500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.325092] ffff8801c0ecb580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.332414] >ffff8801c0ecb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.339737] ^ [ 77.345151] ffff8801c0ecb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.352567] ffff8801c0ecb700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.359889] ================================================================== [ 77.367211] Disabling lock debugging due to kernel taint [ 77.372622] Kernel panic - not syncing: panic_on_warn set ... [ 77.372622] [ 77.379950] CPU: 0 PID: 2980 Comm: syzkaller154453 Tainted: G B 4.14.0-rc5+ #47 [ 77.388487] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 77.397803] Call Trace: [ 77.400358] dump_stack+0x194/0x257 [ 77.403950] ? arch_local_irq_restore+0x53/0x53 [ 77.408584] ? kasan_end_report+0x32/0x50 [ 77.412784] ? lock_downgrade+0x990/0x990 [ 77.416897] ? __internal_add_timer+0x1c0/0x2d0 [ 77.421533] panic+0x1e4/0x417 [ 77.424691] ? __warn+0x1d9/0x1d9 [ 77.428116] ? __internal_add_timer+0x275/0x2d0 [ 77.432749] kasan_end_report+0x50/0x50 [ 77.436686] kasan_report+0x144/0x340 [ 77.440453] __asan_report_store8_noabort+0x17/0x20 [ 77.445431] __internal_add_timer+0x275/0x2d0 [ 77.449889] ? calc_wheel_index+0x200/0x200 [ 77.454181] mod_timer+0x622/0x15b0 [ 77.457776] ? mod_timer_pending+0x14e0/0x14e0 [ 77.462323] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 77.467304] ? trace_hardirqs_on+0xd/0x10 [ 77.471418] ? _crng_backtrack_protect+0xd9/0x130 [ 77.476227] ? __lock_is_held+0xb6/0x140 [ 77.480262] ? __lockdep_init_map+0xe4/0x650 [ 77.484641] ? lockdep_init_map+0x9/0x10 [ 77.488666] ? init_timer_key+0x126/0x3b0 [ 77.492782] ? try_to_del_timer_sync+0x120/0x120 [ 77.497503] ? round_jiffies_up+0xce/0x100 [ 77.501701] ? __round_jiffies_up_relative+0x150/0x150 [ 77.506942] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 77.511840] __tun_chr_ioctl+0x1b17/0x3d20 [ 77.516045] ? tun_chr_read_iter+0x1e0/0x1e0 [ 77.520415] ? find_held_lock+0x35/0x1d0 [ 77.524447] ? __might_sleep+0x95/0x190 [ 77.528385] ? handle_mm_fault+0x248/0x8d0 [ 77.532591] ? selinux_file_ioctl+0x444/0x690 [ 77.537053] ? __fget_light+0x297/0x380 [ 77.540992] ? selinux_capable+0x40/0x40 [ 77.545023] ? handle_mm_fault+0x410/0x8d0 [ 77.549223] tun_chr_compat_ioctl+0x29/0x30 [ 77.553507] ? tun_chr_compat_ioctl+0x29/0x30 [ 77.557969] compat_SyS_ioctl+0x1d7/0x3290 [ 77.562166] ? up_read+0x1a/0x40 [ 77.565499] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 77.569874] ? do_ioctl+0x60/0x60 [ 77.573295] ? do_fast_syscall_32+0x158/0xf05 [ 77.577754] ? do_ioctl+0x60/0x60 [ 77.581171] do_fast_syscall_32+0x3f2/0xf05 [ 77.585462] ? do_int80_syscall_32+0x940/0x940 [ 77.590008] ? kasan_check_read+0x11/0x20 [ 77.594118] ? syscall_return_slowpath+0x510/0x510 [ 77.599014] ? SyS_rt_sigaction+0x94/0x1b0 [ 77.603215] ? SyS_sigprocmask+0x4b0/0x4b0 [ 77.607415] ? SyS_read+0x184/0x220 [ 77.611009] ? retint_user+0x18/0x20 [ 77.614690] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 77.619501] entry_SYSENTER_compat+0x51/0x60 [ 77.623870] RIP: 0023:0xf7feec79 [ 77.627197] RSP: 002b:00000000ffc5bb6c EFLAGS: 00000282 ORIG_RAX: 0000000000000036 [ 77.634868] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000400454ca [ 77.642104] RDX: 0000000020927fd8 RSI: 00000000080ef00c RDI: 000000000000003f [ 77.649338] RBP: 0000000000001000 R08: 0000000000000000 R09: 0000000000000000 [ 77.656573] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 77.663807] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 77.671081] Dumping ftrace buffer: [ 77.674583] (ftrace buffer empty) [ 77.678259] Kernel Offset: disabled [ 77.681853] Rebooting in 86400 seconds..