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-next-kasan-gce-7,10.128.0.63' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 60.452647] ================================================================== [ 60.460094] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 60.467081] Write of size 8 at addr ffff8801ce6d36c8 by task syzkaller812227/2987 [ 60.474669] [ 60.476268] CPU: 1 PID: 2987 Comm: syzkaller812227 Not tainted 4.13.0-next-20170907+ #17 [ 60.484464] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.493788] Call Trace: [ 60.496350] dump_stack+0x194/0x257 [ 60.499954] ? arch_local_irq_restore+0x53/0x53 [ 60.504598] ? show_regs_print_info+0x65/0x65 [ 60.509070] ? __kernel_text_address+0xae/0xe0 [ 60.513624] ? __internal_add_timer+0x275/0x2d0 [ 60.518266] print_address_description+0x73/0x250 [ 60.523081] ? __internal_add_timer+0x275/0x2d0 [ 60.527722] kasan_report+0x24e/0x340 [ 60.531501] __asan_report_store8_noabort+0x17/0x20 [ 60.536488] __internal_add_timer+0x275/0x2d0 [ 60.540960] ? calc_wheel_index+0x200/0x200 [ 60.545274] mod_timer+0x622/0x15b0 [ 60.548891] ? mod_timer_pending+0x14e0/0x14e0 [ 60.553443] ? __lock_is_held+0xbc/0x140 [ 60.557500] ? __lock_is_held+0xbc/0x140 [ 60.561535] ? __lockdep_init_map+0xe4/0x650 [ 60.565921] ? lockdep_init_map+0x3d/0x70 [ 60.570042] ? rcu_read_lock_sched_held+0x108/0x120 [ 60.575034] ? init_timer_key+0x126/0x3b0 [ 60.579169] ? try_to_del_timer_sync+0x120/0x120 [ 60.583903] ? round_jiffies_up+0xce/0x100 [ 60.588115] ? __round_jiffies_up_relative+0x150/0x150 [ 60.593388] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 60.598302] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 60.603821] __tun_chr_ioctl+0x1b23/0x3d20 [ 60.608043] ? tun_chr_read_iter+0x1e0/0x1e0 [ 60.612436] ? lock_downgrade+0x990/0x990 [ 60.616590] ? check_same_owner+0x320/0x320 [ 60.620883] ? __handle_mm_fault+0x39c0/0x39c0 [ 60.625437] ? vmacache_find+0x61/0x270 [ 60.629385] ? tun_chr_compat_ioctl+0x30/0x30 [ 60.633853] tun_chr_ioctl+0x2a/0x40 [ 60.637536] ? tun_chr_ioctl+0x2a/0x40 [ 60.641398] do_vfs_ioctl+0x1b1/0x1530 [ 60.645264] ? ioctl_preallocate+0x2b0/0x2b0 [ 60.649652] ? selinux_capable+0x40/0x40 [ 60.653689] ? putname+0xf3/0x130 [ 60.657151] ? do_sys_open+0x320/0x6d0 [ 60.661019] ? security_file_ioctl+0x7d/0xb0 [ 60.665401] ? security_file_ioctl+0x89/0xb0 [ 60.669785] SyS_ioctl+0x8f/0xc0 [ 60.673134] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 60.677864] RIP: 0033:0x443da9 [ 60.681025] RSP: 002b:00007ffd7a3b8418 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 60.688717] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443da9 [ 60.695973] RDX: 00000000201a9fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 60.703216] RBP: 0000000000000082 R08: 0000f8ff00000000 R09: 0000000000000000 [ 60.710456] R10: 000000000000ffff R11: 0000000000000206 R12: 53d9f2435a307911 [ 60.717709] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 60.724982] [ 60.726583] Allocated by task 2987: [ 60.730193] save_stack_trace+0x16/0x20 [ 60.734141] save_stack+0x43/0xd0 [ 60.737565] kasan_kmalloc+0xad/0xe0 [ 60.741250] __kmalloc_node+0x47/0x70 [ 60.745020] kvmalloc_node+0x64/0xd0 [ 60.748705] alloc_netdev_mqs+0x16e/0xed0 [ 60.752824] __tun_chr_ioctl+0x12be/0x3d20 [ 60.757027] tun_chr_ioctl+0x2a/0x40 [ 60.760712] do_vfs_ioctl+0x1b1/0x1530 [ 60.764570] SyS_ioctl+0x8f/0xc0 [ 60.767907] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 60.772628] [ 60.774226] Freed by task 2987: [ 60.777475] save_stack_trace+0x16/0x20 [ 60.781419] save_stack+0x43/0xd0 [ 60.784839] kasan_slab_free+0x71/0xc0 [ 60.788707] kfree+0xca/0x250 [ 60.791783] kvfree+0x36/0x60 [ 60.794868] free_netdev+0x2cf/0x360 [ 60.798551] __tun_chr_ioctl+0x2cf6/0x3d20 [ 60.802756] tun_chr_ioctl+0x2a/0x40 [ 60.806440] do_vfs_ioctl+0x1b1/0x1530 [ 60.810296] SyS_ioctl+0x8f/0xc0 [ 60.813641] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 60.818374] [ 60.819976] The buggy address belongs to the object at ffff8801ce6d02c0 [ 60.819976] which belongs to the cache kmalloc-16384 of size 16384 [ 60.832955] The buggy address is located 13320 bytes inside of [ 60.832955] 16384-byte region [ffff8801ce6d02c0, ffff8801ce6d42c0) [ 60.845146] The buggy address belongs to the page: [ 60.850049] page:ffffea000739b400 count:1 mapcount:0 mapping:ffff8801ce6d02c0 index:0x0 compound_mapcount: 0 [ 60.860000] flags: 0x200000000008100(slab|head) [ 60.864642] raw: 0200000000008100 ffff8801ce6d02c0 0000000000000000 0000000100000001 [ 60.872506] raw: ffffea0007021e20 ffffea000739b820 ffff8801dac02200 0000000000000000 [ 60.880357] page dumped because: kasan: bad access detected [ 60.886035] [ 60.887632] Memory state around the buggy address: [ 60.892532] ffff8801ce6d3580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.899860] ffff8801ce6d3600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.907188] >ffff8801ce6d3680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.914524] ^ [ 60.920204] ffff8801ce6d3700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.927542] ffff8801ce6d3780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.934870] ================================================================== [ 60.942204] Disabling lock debugging due to kernel taint [ 60.947617] Kernel panic - not syncing: panic_on_warn set ... [ 60.947617] [ 60.954944] CPU: 1 PID: 2987 Comm: syzkaller812227 Tainted: G B 4.13.0-next-20170907+ #17 [ 60.964348] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.973667] Call Trace: [ 60.976224] dump_stack+0x194/0x257 [ 60.979829] ? arch_local_irq_restore+0x53/0x53 [ 60.984476] ? vprintk_default+0x28/0x30 [ 60.988505] ? __internal_add_timer+0x1e0/0x2d0 [ 60.993142] panic+0x1e4/0x417 [ 60.996299] ? __warn+0x1d9/0x1d9 [ 60.999726] ? __internal_add_timer+0x275/0x2d0 [ 61.004361] kasan_end_report+0x50/0x50 [ 61.008298] kasan_report+0x137/0x340 [ 61.012065] __asan_report_store8_noabort+0x17/0x20 [ 61.017044] __internal_add_timer+0x275/0x2d0 [ 61.021505] ? calc_wheel_index+0x200/0x200 [ 61.025797] mod_timer+0x622/0x15b0 [ 61.029392] ? mod_timer_pending+0x14e0/0x14e0 [ 61.033956] ? __lock_is_held+0xbc/0x140 [ 61.037989] ? __lock_is_held+0xbc/0x140 [ 61.042015] ? __lockdep_init_map+0xe4/0x650 [ 61.046389] ? lockdep_init_map+0x3d/0x70 [ 61.050503] ? rcu_read_lock_sched_held+0x108/0x120 [ 61.055487] ? init_timer_key+0x126/0x3b0 [ 61.059601] ? try_to_del_timer_sync+0x120/0x120 [ 61.064322] ? round_jiffies_up+0xce/0x100 [ 61.068523] ? __round_jiffies_up_relative+0x150/0x150 [ 61.073765] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 61.078663] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 61.084177] __tun_chr_ioctl+0x1b23/0x3d20 [ 61.088383] ? tun_chr_read_iter+0x1e0/0x1e0 [ 61.092761] ? lock_downgrade+0x990/0x990 [ 61.096888] ? check_same_owner+0x320/0x320 [ 61.101183] ? __handle_mm_fault+0x39c0/0x39c0 [ 61.105737] ? vmacache_find+0x61/0x270 [ 61.109679] ? tun_chr_compat_ioctl+0x30/0x30 [ 61.114137] tun_chr_ioctl+0x2a/0x40 [ 61.117815] ? tun_chr_ioctl+0x2a/0x40 [ 61.121670] do_vfs_ioctl+0x1b1/0x1530 [ 61.125538] ? ioctl_preallocate+0x2b0/0x2b0 [ 61.129912] ? selinux_capable+0x40/0x40 [ 61.133948] ? putname+0xf3/0x130 [ 61.137369] ? do_sys_open+0x320/0x6d0 [ 61.141238] ? security_file_ioctl+0x7d/0xb0 [ 61.145612] ? security_file_ioctl+0x89/0xb0 [ 61.149986] SyS_ioctl+0x8f/0xc0 [ 61.153320] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 61.158040] RIP: 0033:0x443da9 [ 61.161196] RSP: 002b:00007ffd7a3b8418 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 61.168875] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443da9 [ 61.176199] RDX: 00000000201a9fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 61.183433] RBP: 0000000000000082 R08: 0000f8ff00000000 R09: 0000000000000000 [ 61.190667] R10: 000000000000ffff R11: 0000000000000206 R12: 53d9f2435a307911 [ 61.197903] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000