INIT: Entering runlevel: 2 [[36minfo[39;49m] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added 'ci-upstream-kasan-gce-7,10.128.15.193' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 48.231813] ================================================================== [ 48.232957] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 48.233948] Write of size 8 at addr ffff8801cfc43640 by task syzkaller021846/3003 [ 48.234943] [ 48.235175] CPU: 1 PID: 3003 Comm: syzkaller021846 Not tainted 4.13.0-rc6+ #45 [ 48.236243] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.237461] Call Trace: [ 48.237818] dump_stack+0x194/0x257 [ 48.238340] ? arch_local_irq_restore+0x53/0x53 [ 48.238980] ? show_regs_print_info+0x65/0x65 [ 48.239610] ? __internal_add_timer+0x275/0x2d0 [ 48.240250] print_address_description+0x73/0x250 [ 48.240938] ? __internal_add_timer+0x275/0x2d0 [ 48.241577] kasan_report+0x24e/0x340 [ 48.242094] __asan_report_store8_noabort+0x17/0x20 [ 48.242760] __internal_add_timer+0x275/0x2d0 [ 48.243387] ? calc_wheel_index+0x200/0x200 [ 48.243990] mod_timer+0x6e8/0xf40 [ 48.244474] ? mod_timer_pending+0xe80/0xe80 [ 48.245064] ? __lock_is_held+0xb6/0x140 [ 48.245613] ? lockdep_init_map+0xe4/0x650 [ 48.246322] ? try_to_del_timer_sync+0x120/0x120 [ 48.247004] ? round_jiffies_up+0xce/0x100 [ 48.247573] ? __round_jiffies_up_relative+0x150/0x150 [ 48.248271] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 48.248952] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 48.249698] __tun_chr_ioctl+0x1b20/0x3d60 [ 48.250290] ? unwind_dump+0x4/0x4c0 [ 48.250798] ? tun_select_queue+0x580/0x580 [ 48.251417] ? check_noncircular+0x20/0x20 [ 48.251998] ? save_stack+0xa3/0xd0 [ 48.255606] ? __handle_mm_fault+0x577/0x3860 [ 48.260066] ? check_noncircular+0x20/0x20 [ 48.264280] ? check_noncircular+0x20/0x20 [ 48.268481] ? __pmd_alloc+0x4e0/0x4e0 [ 48.272352] ? check_same_owner+0x320/0x320 [ 48.276640] ? handle_mm_fault+0x23e/0x860 [ 48.280852] ? tun_chr_compat_ioctl+0x30/0x30 [ 48.285320] tun_chr_ioctl+0x2a/0x40 [ 48.289005] ? tun_chr_ioctl+0x2a/0x40 [ 48.292864] do_vfs_ioctl+0x1b1/0x1520 [ 48.296723] ? ioctl_preallocate+0x2b0/0x2b0 [ 48.301106] ? selinux_capable+0x40/0x40 [ 48.305147] ? __handle_mm_fault+0x3860/0x3860 [ 48.309723] ? security_file_ioctl+0x7d/0xb0 [ 48.314114] ? security_file_ioctl+0x89/0xb0 [ 48.318500] SyS_ioctl+0x8f/0xc0 [ 48.321848] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 48.326580] RIP: 0033:0x443d69 [ 48.329740] RSP: 002b:00007fff01be0a28 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 48.337419] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d69 [ 48.344664] RDX: 00000000208b1000 RSI: 00000000400454ca RDI: 0000000000000004 [ 48.351907] RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 [ 48.359146] R10: 0000000000000000 R11: 0000000000000202 R12: c88d3fbc52b5a1d8 [ 48.366480] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 48.373740] [ 48.375335] Allocated by task 3003: [ 48.378935] save_stack_trace+0x16/0x20 [ 48.382878] save_stack+0x43/0xd0 [ 48.386296] kasan_kmalloc+0xad/0xe0 [ 48.389976] __kmalloc_node+0x47/0x70 [ 48.393745] kvmalloc_node+0x64/0xd0 [ 48.397429] alloc_netdev_mqs+0x16e/0xed0 [ 48.401547] __tun_chr_ioctl+0x12b2/0x3d60 [ 48.405749] tun_chr_ioctl+0x2a/0x40 [ 48.409430] do_vfs_ioctl+0x1b1/0x1520 [ 48.413286] SyS_ioctl+0x8f/0xc0 [ 48.416637] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 48.421356] [ 48.422951] Freed by task 3003: [ 48.426200] save_stack_trace+0x16/0x20 [ 48.430148] save_stack+0x43/0xd0 [ 48.433568] kasan_slab_free+0x71/0xc0 [ 48.437422] kfree+0xca/0x250 [ 48.440497] kvfree+0x36/0x60 [ 48.443575] free_netdev+0x2cf/0x360 [ 48.447263] __tun_chr_ioctl+0x2d24/0x3d60 [ 48.451468] tun_chr_ioctl+0x2a/0x40 [ 48.455148] do_vfs_ioctl+0x1b1/0x1520 [ 48.459003] SyS_ioctl+0x8f/0xc0 [ 48.462335] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 48.467057] [ 48.468654] The buggy address belongs to the object at ffff8801cfc40300 [ 48.468654] which belongs to the cache kmalloc-16384 of size 16384 [ 48.481630] The buggy address is located 13120 bytes inside of [ 48.481630] 16384-byte region [ffff8801cfc40300, ffff8801cfc44300) [ 48.493821] The buggy address belongs to the page: [ 48.498722] page:ffffea00073f1000 count:1 mapcount:0 mapping:ffff8801cfc40300 index:0x0 compound_mapcount: 0 [ 48.508665] flags: 0x200000000008100(slab|head) [ 48.513304] raw: 0200000000008100 ffff8801cfc40300 0000000000000000 0000000100000001 [ 48.521151] raw: ffffea0007590420 ffffea000741e820 ffff8801dac02200 0000000000000000 [ 48.528994] page dumped because: kasan: bad access detected [ 48.534665] [ 48.536257] Memory state around the buggy address: [ 48.541157] ffff8801cfc43500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.548491] ffff8801cfc43580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.555835] >ffff8801cfc43600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.563164] ^ [ 48.568591] ffff8801cfc43680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.575914] ffff8801cfc43700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.583236] ================================================================== [ 48.590560] Disabling lock debugging due to kernel taint [ 48.595981] Kernel panic - not syncing: panic_on_warn set ... [ 48.595981] [ 48.603310] CPU: 1 PID: 3003 Comm: syzkaller021846 Tainted: G B 4.13.0-rc6+ #45 [ 48.611846] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.621276] Call Trace: [ 48.623836] dump_stack+0x194/0x257 [ 48.627434] ? arch_local_irq_restore+0x53/0x53 [ 48.632070] ? kasan_end_report+0x32/0x50 [ 48.636184] ? lock_downgrade+0x990/0x990 [ 48.640308] ? __internal_add_timer+0x250/0x2d0 [ 48.644944] panic+0x1e4/0x417 [ 48.648104] ? __warn+0x1d9/0x1d9 [ 48.651542] ? __internal_add_timer+0x275/0x2d0 [ 48.656176] kasan_end_report+0x50/0x50 [ 48.660214] kasan_report+0x137/0x340 [ 48.663982] __asan_report_store8_noabort+0x17/0x20 [ 48.668962] __internal_add_timer+0x275/0x2d0 [ 48.673423] ? calc_wheel_index+0x200/0x200 [ 48.677720] mod_timer+0x6e8/0xf40 [ 48.681229] ? mod_timer_pending+0xe80/0xe80 [ 48.685604] ? __lock_is_held+0xb6/0x140 [ 48.689635] ? lockdep_init_map+0xe4/0x650 [ 48.693838] ? try_to_del_timer_sync+0x120/0x120 [ 48.698559] ? round_jiffies_up+0xce/0x100 [ 48.702761] ? __round_jiffies_up_relative+0x150/0x150 [ 48.708004] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 48.712903] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 48.718411] __tun_chr_ioctl+0x1b20/0x3d60 [ 48.722615] ? unwind_dump+0x4/0x4c0 [ 48.726301] ? tun_select_queue+0x580/0x580 [ 48.730589] ? check_noncircular+0x20/0x20 [ 48.734799] ? save_stack+0xa3/0xd0 [ 48.738395] ? __handle_mm_fault+0x577/0x3860 [ 48.742855] ? check_noncircular+0x20/0x20 [ 48.747064] ? check_noncircular+0x20/0x20 [ 48.751269] ? __pmd_alloc+0x4e0/0x4e0 [ 48.755130] ? check_same_owner+0x320/0x320 [ 48.759415] ? handle_mm_fault+0x23e/0x860 [ 48.763621] ? tun_chr_compat_ioctl+0x30/0x30 [ 48.768080] tun_chr_ioctl+0x2a/0x40 [ 48.771762] ? tun_chr_ioctl+0x2a/0x40 [ 48.775617] do_vfs_ioctl+0x1b1/0x1520 [ 48.779471] ? ioctl_preallocate+0x2b0/0x2b0 [ 48.783850] ? selinux_capable+0x40/0x40 [ 48.787878] ? __handle_mm_fault+0x3860/0x3860 [ 48.792453] ? security_file_ioctl+0x7d/0xb0 [ 48.796826] ? security_file_ioctl+0x89/0xb0 [ 48.801201] SyS_ioctl+0x8f/0xc0 [ 48.804540] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 48.809272] RIP: 0033:0x443d69 [ 48.812428] RSP: 002b:00007fff01be0a28 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 48.820102] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d69 [ 48.827436] RDX: 00000000208b1000 RSI: 00000000400454ca RDI: 0000000000000004 [ 48.834673] RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 [ 48.841923] R10: 0000000000000000 R11: 0000000000000202 R12: c88d3fbc52b5a1d8 [ 48.849159] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 48.856740] Dumping ftrace buffer: [ 48.860246] (ftrace buffer empty) [ 48.863921] Kernel Offset: disabled [ 48.867517] Rebooting in 86400 seconds..