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-4,10.128.0.53' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 32.858861] ================================================================== [ 32.860020] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 32.860958] Write of size 8 at addr ffff8801d1e03600 by task syzkaller850253/2982 [ 32.861956] [ 32.862190] CPU: 0 PID: 2982 Comm: syzkaller850253 Not tainted 4.14.0-rc5+ #139 [ 32.863196] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.864435] Call Trace: [ 32.864796] dump_stack+0x194/0x257 [ 32.865305] ? arch_local_irq_restore+0x53/0x53 [ 32.865927] ? show_regs_print_info+0x65/0x65 [ 32.866533] ? __kernel_text_address+0xd/0x40 [ 32.867134] ? __internal_add_timer+0x275/0x2d0 [ 32.867761] print_address_description+0x73/0x250 [ 32.868408] ? __internal_add_timer+0x275/0x2d0 [ 32.869032] kasan_report+0x25b/0x340 [ 32.869548] __asan_report_store8_noabort+0x17/0x20 [ 32.870218] __internal_add_timer+0x275/0x2d0 [ 32.870821] ? calc_wheel_index+0x200/0x200 [ 32.871410] mod_timer+0x622/0x15b0 [ 32.871910] ? mod_timer_pending+0x14e0/0x14e0 [ 32.872539] ? __lock_is_held+0xb6/0x140 [ 32.873109] ? __lock_is_held+0xb6/0x140 [ 32.873659] ? __lockdep_init_map+0xe4/0x650 [ 32.874252] ? lockdep_init_map+0x9/0x10 [ 32.874798] ? init_timer_key+0x126/0x3b0 [ 32.875356] ? try_to_del_timer_sync+0x120/0x120 [ 32.875993] ? round_jiffies_up+0xce/0x100 [ 32.876561] ? __round_jiffies_up_relative+0x150/0x150 [ 32.877264] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 32.877922] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 32.878663] __tun_chr_ioctl+0x1b17/0x3d20 [ 32.879250] ? tun_chr_read_iter+0x1e0/0x1e0 [ 32.883624] ? find_held_lock+0x35/0x1d0 [ 32.887664] ? __do_page_fault+0x64c/0xd60 [ 32.891867] ? lock_downgrade+0x990/0x990 [ 32.895992] ? handle_mm_fault+0x410/0x8d0 [ 32.900207] ? check_same_owner+0x320/0x320 [ 32.904493] ? up_read+0x1a/0x40 [ 32.907826] ? __do_page_fault+0x3d6/0xd60 [ 32.912032] ? tun_chr_compat_ioctl+0x30/0x30 [ 32.916493] tun_chr_ioctl+0x2a/0x40 [ 32.920176] ? tun_chr_ioctl+0x2a/0x40 [ 32.924037] do_vfs_ioctl+0x1b1/0x1520 [ 32.927901] ? ioctl_preallocate+0x2b0/0x2b0 [ 32.932280] ? selinux_capable+0x40/0x40 [ 32.936312] ? putname+0xf3/0x130 [ 32.939735] ? do_sys_open+0x320/0x6d0 [ 32.943598] ? security_file_ioctl+0x89/0xb0 [ 32.947980] SyS_ioctl+0x8f/0xc0 [ 32.951323] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 32.956043] RIP: 0033:0x443dc9 [ 32.959199] RSP: 002b:00007ffd48c11068 EFLAGS: 00000207 ORIG_RAX: 0000000000000010 [ 32.966876] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443dc9 [ 32.974114] RDX: 0000000020927fd8 RSI: 00000000400454ca RDI: 0000000000000006 [ 32.981350] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 32.988585] R10: 0000000000000000 R11: 0000000000000207 R12: 2f70af7d216a7f87 [ 32.995822] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 33.003073] [ 33.004669] Allocated by task 2982: [ 33.008262] save_stack_trace+0x16/0x20 [ 33.012203] save_stack+0x43/0xd0 [ 33.015628] kasan_kmalloc+0xad/0xe0 [ 33.019306] __kmalloc_node+0x47/0x70 [ 33.023074] kvmalloc_node+0x64/0xd0 [ 33.026754] alloc_netdev_mqs+0x16e/0xed0 [ 33.030867] __tun_chr_ioctl+0x12b2/0x3d20 [ 33.035067] tun_chr_ioctl+0x2a/0x40 [ 33.038747] do_vfs_ioctl+0x1b1/0x1520 [ 33.042598] SyS_ioctl+0x8f/0xc0 [ 33.045931] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.050649] [ 33.052242] Freed by task 2982: [ 33.055486] save_stack_trace+0x16/0x20 [ 33.059424] save_stack+0x43/0xd0 [ 33.062843] kasan_slab_free+0x71/0xc0 [ 33.066696] kfree+0xca/0x250 [ 33.069770] kvfree+0x36/0x60 [ 33.072842] free_netdev+0x2cf/0x360 [ 33.076521] __tun_chr_ioctl+0x2cea/0x3d20 [ 33.080719] tun_chr_ioctl+0x2a/0x40 [ 33.084398] do_vfs_ioctl+0x1b1/0x1520 [ 33.088251] SyS_ioctl+0x8f/0xc0 [ 33.091584] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.096304] [ 33.097903] The buggy address belongs to the object at ffff8801d1e002c0 [ 33.097903] which belongs to the cache kmalloc-16384 of size 16384 [ 33.110870] The buggy address is located 13120 bytes inside of [ 33.110870] 16384-byte region [ffff8801d1e002c0, ffff8801d1e042c0) [ 33.123058] The buggy address belongs to the page: [ 33.127954] page:ffffea0007478000 count:1 mapcount:0 mapping:ffff8801d1e002c0 index:0x0 compound_mapcount: 0 [ 33.137891] flags: 0x200000000008100(slab|head) [ 33.142526] raw: 0200000000008100 ffff8801d1e002c0 0000000000000000 0000000100000001 [ 33.150373] raw: ffffea0007649820 ffffea0007475220 ffff8801dac02200 0000000000000000 [ 33.158217] page dumped because: kasan: bad access detected [ 33.163890] [ 33.165485] Memory state around the buggy address: [ 33.170379] ffff8801d1e03500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.177702] ffff8801d1e03580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.185027] >ffff8801d1e03600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.192348] ^ [ 33.195677] ffff8801d1e03680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.203000] ffff8801d1e03700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.210321] ================================================================== [ 33.217642] Disabling lock debugging due to kernel taint [ 33.223054] Kernel panic - not syncing: panic_on_warn set ... [ 33.223054] [ 33.230379] CPU: 0 PID: 2982 Comm: syzkaller850253 Tainted: G B 4.14.0-rc5+ #139 [ 33.239002] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.248321] Call Trace: [ 33.250879] dump_stack+0x194/0x257 [ 33.254473] ? arch_local_irq_restore+0x53/0x53 [ 33.259104] ? kasan_end_report+0x32/0x50 [ 33.263236] ? lock_downgrade+0x990/0x990 [ 33.267353] ? __internal_add_timer+0x1c0/0x2d0 [ 33.271989] panic+0x1e4/0x417 [ 33.275148] ? __warn+0x1d9/0x1d9 [ 33.278570] ? __internal_add_timer+0x275/0x2d0 [ 33.283203] kasan_end_report+0x50/0x50 [ 33.287142] kasan_report+0x144/0x340 [ 33.290911] __asan_report_store8_noabort+0x17/0x20 [ 33.295892] __internal_add_timer+0x275/0x2d0 [ 33.300351] ? calc_wheel_index+0x200/0x200 [ 33.304643] mod_timer+0x622/0x15b0 [ 33.308239] ? mod_timer_pending+0x14e0/0x14e0 [ 33.312784] ? __lock_is_held+0xb6/0x140 [ 33.316816] ? __lock_is_held+0xb6/0x140 [ 33.320844] ? __lockdep_init_map+0xe4/0x650 [ 33.325220] ? lockdep_init_map+0x9/0x10 [ 33.329246] ? init_timer_key+0x126/0x3b0 [ 33.333359] ? try_to_del_timer_sync+0x120/0x120 [ 33.338079] ? round_jiffies_up+0xce/0x100 [ 33.342279] ? __round_jiffies_up_relative+0x150/0x150 [ 33.347520] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.352417] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 33.357923] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.362126] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.366497] ? find_held_lock+0x35/0x1d0 [ 33.370528] ? __do_page_fault+0x64c/0xd60 [ 33.374726] ? lock_downgrade+0x990/0x990 [ 33.378844] ? handle_mm_fault+0x410/0x8d0 [ 33.383055] ? check_same_owner+0x320/0x320 [ 33.387339] ? up_read+0x1a/0x40 [ 33.390672] ? __do_page_fault+0x3d6/0xd60 [ 33.394874] ? tun_chr_compat_ioctl+0x30/0x30 [ 33.399333] tun_chr_ioctl+0x2a/0x40 [ 33.403011] ? tun_chr_ioctl+0x2a/0x40 [ 33.406868] do_vfs_ioctl+0x1b1/0x1520 [ 33.410722] ? ioctl_preallocate+0x2b0/0x2b0 [ 33.415095] ? selinux_capable+0x40/0x40 [ 33.419123] ? putname+0xf3/0x130 [ 33.422545] ? do_sys_open+0x320/0x6d0 [ 33.426402] ? security_file_ioctl+0x89/0xb0 [ 33.430776] SyS_ioctl+0x8f/0xc0 [ 33.434112] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.438832] RIP: 0033:0x443dc9 [ 33.441989] RSP: 002b:00007ffd48c11068 EFLAGS: 00000207 ORIG_RAX: 0000000000000010 [ 33.449660] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443dc9 [ 33.456896] RDX: 0000000020927fd8 RSI: 00000000400454ca RDI: 0000000000000006 [ 33.464132] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 33.471367] R10: 0000000000000000 R11: 0000000000000207 R12: 2f70af7d216a7f87 [ 33.478602] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 33.486228] Dumping ftrace buffer: [ 33.489734] (ftrace buffer empty) [ 33.493411] Kernel Offset: disabled [ 33.497005] Rebooting in 86400 seconds..