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-4,10.128.0.32' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 33.849719] ================================================================== [ 33.850834] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 33.851754] Write of size 8 at addr ffff8801d21b3500 by task syzkaller307360/2985 [ 33.852748] [ 33.852982] CPU: 1 PID: 2985 Comm: syzkaller307360 Not tainted 4.14.0-rc5+ #140 [ 33.853956] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.855174] Call Trace: [ 33.855531] dump_stack+0x194/0x257 [ 33.856021] ? arch_local_irq_restore+0x53/0x53 [ 33.856642] ? show_regs_print_info+0x65/0x65 [ 33.857246] ? __kernel_text_address+0xd/0x40 [ 33.857845] ? __internal_add_timer+0x275/0x2d0 [ 33.858470] print_address_description+0x73/0x250 [ 33.859114] ? __internal_add_timer+0x275/0x2d0 [ 33.859738] kasan_report+0x25b/0x340 [ 33.860251] __asan_report_store8_noabort+0x17/0x20 [ 33.860926] __internal_add_timer+0x275/0x2d0 [ 33.861528] ? calc_wheel_index+0x200/0x200 [ 33.862114] mod_timer+0x622/0x15b0 [ 33.862612] ? mod_timer_pending+0x14e0/0x14e0 [ 33.863235] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 33.863913] ? trace_hardirqs_on+0xd/0x10 [ 33.864482] ? _crng_backtrack_protect+0xd9/0x130 [ 33.865135] ? __lock_is_held+0xb6/0x140 [ 33.865683] ? __lockdep_init_map+0xe4/0x650 [ 33.866273] ? lockdep_init_map+0x9/0x10 [ 33.866816] ? init_timer_key+0x126/0x3b0 [ 33.867372] ? try_to_del_timer_sync+0x120/0x120 [ 33.868006] ? round_jiffies_up+0xce/0x100 [ 33.868574] ? __round_jiffies_up_relative+0x150/0x150 [ 33.869273] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.869936] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.874148] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.878518] ? find_held_lock+0x35/0x1d0 [ 33.882550] ? __do_page_fault+0x64c/0xd60 [ 33.886750] ? lock_downgrade+0x990/0x990 [ 33.890869] ? handle_mm_fault+0x410/0x8d0 [ 33.895082] ? check_same_owner+0x320/0x320 [ 33.899368] ? up_read+0x1a/0x40 [ 33.902698] ? __do_page_fault+0x3d6/0xd60 [ 33.906900] ? tun_chr_compat_ioctl+0x30/0x30 [ 33.911357] tun_chr_ioctl+0x2a/0x40 [ 33.915034] ? tun_chr_ioctl+0x2a/0x40 [ 33.918894] do_vfs_ioctl+0x1b1/0x1520 [ 33.922752] ? ioctl_preallocate+0x2b0/0x2b0 [ 33.927133] ? selinux_capable+0x40/0x40 [ 33.931162] ? putname+0xf3/0x130 [ 33.934584] ? do_sys_open+0x320/0x6d0 [ 33.938445] ? security_file_ioctl+0x89/0xb0 [ 33.942822] SyS_ioctl+0x8f/0xc0 [ 33.946161] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.950888] RIP: 0033:0x443d89 [ 33.954044] RSP: 002b:00007fff3ea2af18 EFLAGS: 00000207 ORIG_RAX: 0000000000000010 [ 33.961716] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d89 [ 33.968951] RDX: 0000000020927fd8 RSI: 00000000400454ca RDI: 0000000000000006 [ 33.976192] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 33.983428] R10: 0000000000000000 R11: 0000000000000207 R12: 8d35d13b99062002 [ 33.990663] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 33.997917] [ 33.999514] Allocated by task 2985: [ 34.003112] save_stack_trace+0x16/0x20 [ 34.007056] save_stack+0x43/0xd0 [ 34.010474] kasan_kmalloc+0xad/0xe0 [ 34.014151] __kmalloc_node+0x47/0x70 [ 34.017915] kvmalloc_node+0x64/0xd0 [ 34.021597] alloc_netdev_mqs+0x16e/0xed0 [ 34.025710] __tun_chr_ioctl+0x12b2/0x3d20 [ 34.029908] tun_chr_ioctl+0x2a/0x40 [ 34.033586] do_vfs_ioctl+0x1b1/0x1520 [ 34.037436] SyS_ioctl+0x8f/0xc0 [ 34.040770] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 34.045486] [ 34.047082] Freed by task 2985: [ 34.050329] save_stack_trace+0x16/0x20 [ 34.054265] save_stack+0x43/0xd0 [ 34.057680] kasan_slab_free+0x71/0xc0 [ 34.061528] kfree+0xca/0x250 [ 34.064599] kvfree+0x36/0x60 [ 34.067669] free_netdev+0x2cf/0x360 [ 34.071344] __tun_chr_ioctl+0x2cea/0x3d20 [ 34.075539] tun_chr_ioctl+0x2a/0x40 [ 34.079216] do_vfs_ioctl+0x1b1/0x1520 [ 34.083069] SyS_ioctl+0x8f/0xc0 [ 34.086398] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 34.091121] [ 34.092713] The buggy address belongs to the object at ffff8801d21b01c0 [ 34.092713] which belongs to the cache kmalloc-16384 of size 16384 [ 34.105679] The buggy address is located 13120 bytes inside of [ 34.105679] 16384-byte region [ffff8801d21b01c0, ffff8801d21b41c0) [ 34.117864] The buggy address belongs to the page: [ 34.123150] page:ffffea0007486c00 count:1 mapcount:0 mapping:ffff8801d21b01c0 index:0x0 compound_mapcount: 0 [ 34.133086] flags: 0x200000000008100(slab|head) [ 34.137722] raw: 0200000000008100 ffff8801d21b01c0 0000000000000000 0000000100000001 [ 34.145567] raw: ffffea000765d220 ffffea0007473820 ffff8801dac02200 0000000000000000 [ 34.153670] page dumped because: kasan: bad access detected [ 34.159342] [ 34.160934] Memory state around the buggy address: [ 34.165825] ffff8801d21b3400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.173146] ffff8801d21b3480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.180468] >ffff8801d21b3500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.187789] ^ [ 34.191120] ffff8801d21b3580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.198441] ffff8801d21b3600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.205760] ================================================================== [ 34.213081] Disabling lock debugging due to kernel taint [ 34.218752] Kernel panic - not syncing: panic_on_warn set ... [ 34.218752] [ 34.226077] CPU: 1 PID: 2985 Comm: syzkaller307360 Tainted: G B 4.14.0-rc5+ #140 [ 34.234698] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.244014] Call Trace: [ 34.246572] dump_stack+0x194/0x257 [ 34.250163] ? arch_local_irq_restore+0x53/0x53 [ 34.254794] ? kasan_end_report+0x32/0x50 [ 34.258907] ? lock_downgrade+0x990/0x990 [ 34.263023] ? __internal_add_timer+0x1d0/0x2d0 [ 34.267657] panic+0x1e4/0x417 [ 34.270811] ? __warn+0x1d9/0x1d9 [ 34.274233] ? __internal_add_timer+0x275/0x2d0 [ 34.278866] kasan_end_report+0x50/0x50 [ 34.282801] kasan_report+0x144/0x340 [ 34.286565] __asan_report_store8_noabort+0x17/0x20 [ 34.291542] __internal_add_timer+0x275/0x2d0 [ 34.296002] ? calc_wheel_index+0x200/0x200 [ 34.300290] mod_timer+0x622/0x15b0 [ 34.303885] ? mod_timer_pending+0x14e0/0x14e0 [ 34.308430] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.313412] ? trace_hardirqs_on+0xd/0x10 [ 34.317527] ? _crng_backtrack_protect+0xd9/0x130 [ 34.322338] ? __lock_is_held+0xb6/0x140 [ 34.326365] ? __lockdep_init_map+0xe4/0x650 [ 34.330739] ? lockdep_init_map+0x9/0x10 [ 34.334763] ? init_timer_key+0x126/0x3b0 [ 34.338874] ? try_to_del_timer_sync+0x120/0x120 [ 34.343592] ? round_jiffies_up+0xce/0x100 [ 34.347789] ? __round_jiffies_up_relative+0x150/0x150 [ 34.353031] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 34.357928] __tun_chr_ioctl+0x1b17/0x3d20 [ 34.362131] ? tun_chr_read_iter+0x1e0/0x1e0 [ 34.366500] ? find_held_lock+0x35/0x1d0 [ 34.370532] ? __do_page_fault+0x64c/0xd60 [ 34.374734] ? lock_downgrade+0x990/0x990 [ 34.378849] ? handle_mm_fault+0x410/0x8d0 [ 34.383056] ? check_same_owner+0x320/0x320 [ 34.387340] ? up_read+0x1a/0x40 [ 34.390670] ? __do_page_fault+0x3d6/0xd60 [ 34.394870] ? tun_chr_compat_ioctl+0x30/0x30 [ 34.399326] tun_chr_ioctl+0x2a/0x40 [ 34.403002] ? tun_chr_ioctl+0x2a/0x40 [ 34.406853] do_vfs_ioctl+0x1b1/0x1520 [ 34.410706] ? ioctl_preallocate+0x2b0/0x2b0 [ 34.415081] ? selinux_capable+0x40/0x40 [ 34.419111] ? putname+0xf3/0x130 [ 34.422529] ? do_sys_open+0x320/0x6d0 [ 34.426383] ? security_file_ioctl+0x89/0xb0 [ 34.430755] SyS_ioctl+0x8f/0xc0 [ 34.434092] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 34.438813] RIP: 0033:0x443d89 [ 34.441966] RSP: 002b:00007fff3ea2af18 EFLAGS: 00000207 ORIG_RAX: 0000000000000010 [ 34.449637] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d89 [ 34.456870] RDX: 0000000020927fd8 RSI: 00000000400454ca RDI: 0000000000000006 [ 34.464103] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 34.471333] R10: 0000000000000000 R11: 0000000000000207 R12: 8d35d13b99062002 [ 34.478564] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000