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-8,10.128.0.32' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 33.894681] ================================================================== [ 33.895785] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 33.896708] Write of size 8 at addr ffff8801d2023600 by task syzkaller256797/2985 [ 33.897721] [ 33.897955] CPU: 1 PID: 2985 Comm: syzkaller256797 Not tainted 4.14.0-rc5+ #141 [ 33.898931] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.900167] Call Trace: [ 33.900530] dump_stack+0x194/0x257 [ 33.901021] ? arch_local_irq_restore+0x53/0x53 [ 33.901643] ? show_regs_print_info+0x65/0x65 [ 33.902259] ? __kernel_text_address+0xd/0x40 [ 33.902859] ? __internal_add_timer+0x275/0x2d0 [ 33.903482] print_address_description+0x73/0x250 [ 33.904128] ? __internal_add_timer+0x275/0x2d0 [ 33.904751] kasan_report+0x25b/0x340 [ 33.905267] __asan_report_store8_noabort+0x17/0x20 [ 33.905935] __internal_add_timer+0x275/0x2d0 [ 33.906632] ? calc_wheel_index+0x200/0x200 [ 33.907223] mod_timer+0x622/0x15b0 [ 33.907770] ? mod_timer_pending+0x14e0/0x14e0 [ 33.908383] ? __lock_is_held+0xb6/0x140 [ 33.908941] ? __lock_is_held+0xb6/0x140 [ 33.909508] ? __lockdep_init_map+0xe4/0x650 [ 33.910101] ? lockdep_init_map+0x9/0x10 [ 33.910645] ? init_timer_key+0x126/0x3b0 [ 33.911292] ? try_to_del_timer_sync+0x120/0x120 [ 33.911932] ? round_jiffies_up+0xce/0x100 [ 33.912498] ? __round_jiffies_up_relative+0x150/0x150 [ 33.913198] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.913854] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 33.914595] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.915170] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.919546] ? find_held_lock+0x35/0x1d0 [ 33.923588] ? __do_page_fault+0x64c/0xd60 [ 33.927794] ? lock_downgrade+0x990/0x990 [ 33.931924] ? handle_mm_fault+0x410/0x8d0 [ 33.936143] ? check_same_owner+0x320/0x320 [ 33.940437] ? up_read+0x1a/0x40 [ 33.943773] ? __do_page_fault+0x3d6/0xd60 [ 33.947979] ? tun_chr_compat_ioctl+0x30/0x30 [ 33.952443] tun_chr_ioctl+0x2a/0x40 [ 33.956127] ? tun_chr_ioctl+0x2a/0x40 [ 33.959986] do_vfs_ioctl+0x1b1/0x1520 [ 33.963845] ? ioctl_preallocate+0x2b0/0x2b0 [ 33.968229] ? selinux_capable+0x40/0x40 [ 33.972260] ? putname+0xf3/0x130 [ 33.975685] ? do_sys_open+0x320/0x6d0 [ 33.979550] ? security_file_ioctl+0x89/0xb0 [ 33.983929] SyS_ioctl+0x8f/0xc0 [ 33.987270] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.991990] RIP: 0033:0x443d99 [ 33.995149] RSP: 002b:00007ffc852276a8 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 34.002823] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d99 [ 34.010067] RDX: 0000000020f29fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 34.017309] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 34.024546] R10: 0000000000000000 R11: 0000000000000206 R12: da33dd9dc6a0a3ad [ 34.031782] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 34.039037] [ 34.040631] Allocated by task 2985: [ 34.044230] save_stack_trace+0x16/0x20 [ 34.048174] save_stack+0x43/0xd0 [ 34.051592] kasan_kmalloc+0xad/0xe0 [ 34.055268] __kmalloc_node+0x47/0x70 [ 34.059035] kvmalloc_node+0x64/0xd0 [ 34.062717] alloc_netdev_mqs+0x16e/0xed0 [ 34.066831] __tun_chr_ioctl+0x12b2/0x3d20 [ 34.071032] tun_chr_ioctl+0x2a/0x40 [ 34.074710] do_vfs_ioctl+0x1b1/0x1520 [ 34.078561] SyS_ioctl+0x8f/0xc0 [ 34.081894] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 34.086610] [ 34.088203] Freed by task 2985: [ 34.091448] save_stack_trace+0x16/0x20 [ 34.095387] save_stack+0x43/0xd0 [ 34.098804] kasan_slab_free+0x71/0xc0 [ 34.102655] kfree+0xca/0x250 [ 34.105727] kvfree+0x36/0x60 [ 34.108797] free_netdev+0x2cf/0x360 [ 34.112477] __tun_chr_ioctl+0x2cea/0x3d20 [ 34.116681] tun_chr_ioctl+0x2a/0x40 [ 34.120363] do_vfs_ioctl+0x1b1/0x1520 [ 34.124216] SyS_ioctl+0x8f/0xc0 [ 34.127547] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 34.132265] [ 34.133859] The buggy address belongs to the object at ffff8801d20202c0 [ 34.133859] which belongs to the cache kmalloc-16384 of size 16384 [ 34.146828] The buggy address is located 13120 bytes inside of [ 34.146828] 16384-byte region [ffff8801d20202c0, ffff8801d20242c0) [ 34.159014] The buggy address belongs to the page: [ 34.163910] page:ffffea0007480800 count:1 mapcount:0 mapping:ffff8801d20202c0 index:0x0 compound_mapcount: 0 [ 34.173847] flags: 0x200000000008100(slab|head) [ 34.178482] raw: 0200000000008100 ffff8801d20202c0 0000000000000000 0000000100000001 [ 34.186330] raw: ffffea000765ca20 ffffea000748c820 ffff8801dac02200 0000000000000000 [ 34.194174] page dumped because: kasan: bad access detected [ 34.199845] [ 34.201437] Memory state around the buggy address: [ 34.206332] ffff8801d2023500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.213659] ffff8801d2023580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.220983] >ffff8801d2023600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.228311] ^ [ 34.231641] ffff8801d2023680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.238965] ffff8801d2023700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.246286] ================================================================== [ 34.253614] Disabling lock debugging due to kernel taint [ 34.259028] Kernel panic - not syncing: panic_on_warn set ... [ 34.259028] [ 34.266355] CPU: 1 PID: 2985 Comm: syzkaller256797 Tainted: G B 4.14.0-rc5+ #141 [ 34.274981] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.284303] Call Trace: [ 34.286866] dump_stack+0x194/0x257 [ 34.290460] ? arch_local_irq_restore+0x53/0x53 [ 34.295100] ? kasan_end_report+0x32/0x50 [ 34.299217] ? lock_downgrade+0x990/0x990 [ 34.303333] ? __internal_add_timer+0x1f0/0x2d0 [ 34.307968] panic+0x1e4/0x417 [ 34.311126] ? __warn+0x1d9/0x1d9 [ 34.314549] ? __internal_add_timer+0x275/0x2d0 [ 34.319184] kasan_end_report+0x50/0x50 [ 34.323123] kasan_report+0x144/0x340 [ 34.326889] __asan_report_store8_noabort+0x17/0x20 [ 34.331867] __internal_add_timer+0x275/0x2d0 [ 34.336330] ? calc_wheel_index+0x200/0x200 [ 34.340621] mod_timer+0x622/0x15b0 [ 34.344220] ? mod_timer_pending+0x14e0/0x14e0 [ 34.348767] ? __lock_is_held+0xb6/0x140 [ 34.352799] ? __lock_is_held+0xb6/0x140 [ 34.356828] ? __lockdep_init_map+0xe4/0x650 [ 34.361201] ? lockdep_init_map+0x9/0x10 [ 34.365228] ? init_timer_key+0x126/0x3b0 [ 34.369341] ? try_to_del_timer_sync+0x120/0x120 [ 34.374061] ? round_jiffies_up+0xce/0x100 [ 34.378264] ? __round_jiffies_up_relative+0x150/0x150 [ 34.383504] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 34.388401] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 34.393908] __tun_chr_ioctl+0x1b17/0x3d20 [ 34.398113] ? tun_chr_read_iter+0x1e0/0x1e0 [ 34.402486] ? find_held_lock+0x35/0x1d0 [ 34.406516] ? __do_page_fault+0x64c/0xd60 [ 34.410717] ? lock_downgrade+0x990/0x990 [ 34.414836] ? handle_mm_fault+0x410/0x8d0 [ 34.419047] ? check_same_owner+0x320/0x320 [ 34.423336] ? up_read+0x1a/0x40 [ 34.426674] ? __do_page_fault+0x3d6/0xd60 [ 34.430876] ? tun_chr_compat_ioctl+0x30/0x30 [ 34.435334] tun_chr_ioctl+0x2a/0x40 [ 34.439013] ? tun_chr_ioctl+0x2a/0x40 [ 34.442870] do_vfs_ioctl+0x1b1/0x1520 [ 34.446728] ? ioctl_preallocate+0x2b0/0x2b0 [ 34.451104] ? selinux_capable+0x40/0x40 [ 34.455130] ? putname+0xf3/0x130 [ 34.458551] ? do_sys_open+0x320/0x6d0 [ 34.462410] ? security_file_ioctl+0x89/0xb0 [ 34.466783] SyS_ioctl+0x8f/0xc0 [ 34.470121] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 34.474840] RIP: 0033:0x443d99 [ 34.477993] RSP: 002b:00007ffc852276a8 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 34.485665] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d99 [ 34.492900] RDX: 0000000020f29fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 34.500137] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 34.507371] R10: 0000000000000000 R11: 0000000000000206 R12: da33dd9dc6a0a3ad [ 34.514604] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000