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-mmots-kasan-gce-5,10.128.0.27' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 46.672356] ================================================================== [ 46.679823] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 46.686809] Write of size 8 at addr ffff8801ce2bb688 by task syzkaller013726/2985 [ 46.694396] [ 46.696000] CPU: 0 PID: 2985 Comm: syzkaller013726 Not tainted 4.13.0-mm1+ #7 [ 46.703254] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.712579] Call Trace: [ 46.715146] dump_stack+0x194/0x257 [ 46.718749] ? arch_local_irq_restore+0x53/0x53 [ 46.723394] ? show_regs_print_info+0x65/0x65 [ 46.727869] ? __internal_add_timer+0x275/0x2d0 [ 46.732511] print_address_description+0x73/0x250 [ 46.737329] ? __internal_add_timer+0x275/0x2d0 [ 46.741974] kasan_report+0x24e/0x340 [ 46.745755] __asan_report_store8_noabort+0x17/0x20 [ 46.750745] __internal_add_timer+0x275/0x2d0 [ 46.755222] ? calc_wheel_index+0x200/0x200 [ 46.759532] mod_timer+0x622/0x15b0 [ 46.763150] ? mod_timer_pending+0x14e0/0x14e0 [ 46.767709] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 46.772698] ? trace_hardirqs_on+0xd/0x10 [ 46.776824] ? _crng_backtrack_protect+0xd9/0x130 [ 46.781647] ? __lock_is_held+0xbc/0x140 [ 46.785682] ? __lockdep_init_map+0xe4/0x650 [ 46.790069] ? lockdep_init_map+0x3d/0x70 [ 46.794195] ? rcu_read_lock_sched_held+0x108/0x120 [ 46.799189] ? init_timer_key+0x126/0x3b0 [ 46.803318] ? try_to_del_timer_sync+0x120/0x120 [ 46.808049] ? round_jiffies_up+0xce/0x100 [ 46.812258] ? __round_jiffies_up_relative+0x150/0x150 [ 46.817505] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 46.822419] __tun_chr_ioctl+0x1b23/0x3d20 [ 46.826643] ? tun_chr_read_iter+0x1e0/0x1e0 [ 46.831040] ? lock_downgrade+0x990/0x990 [ 46.835193] ? check_same_owner+0x320/0x320 [ 46.839494] ? __handle_mm_fault+0x39c0/0x39c0 [ 46.844049] ? vmacache_find+0x61/0x270 [ 46.848002] ? tun_chr_compat_ioctl+0x30/0x30 [ 46.852472] tun_chr_ioctl+0x2a/0x40 [ 46.856157] ? tun_chr_ioctl+0x2a/0x40 [ 46.860024] do_vfs_ioctl+0x1b1/0x1530 [ 46.863893] ? ioctl_preallocate+0x2b0/0x2b0 [ 46.868280] ? selinux_capable+0x40/0x40 [ 46.872316] ? putname+0xf3/0x130 [ 46.875748] ? do_sys_open+0x320/0x6d0 [ 46.879622] ? security_file_ioctl+0x7d/0xb0 [ 46.884003] ? security_file_ioctl+0x89/0xb0 [ 46.888390] SyS_ioctl+0x8f/0xc0 [ 46.891741] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 46.896471] RIP: 0033:0x443d79 [ 46.899637] RSP: 002b:00007ffc0e02c258 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 46.907319] RAX: ffffffffffffffda RBX: f1ce4a65c3b97a7a RCX: 0000000000443d79 [ 46.914560] RDX: 0000000020927fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 46.921799] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 46.929037] R10: 0000000000000000 R11: 0000000000000202 R12: d7c29eea7c696697 [ 46.936276] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 46.943534] [ 46.945135] Allocated by task 2985: [ 46.948735] save_stack_trace+0x16/0x20 [ 46.952679] save_stack+0x43/0xd0 [ 46.956100] kasan_kmalloc+0xad/0xe0 [ 46.959783] __kmalloc_node+0x47/0x70 [ 46.963552] kvmalloc_node+0x64/0xd0 [ 46.967236] alloc_netdev_mqs+0x16e/0xed0 [ 46.971350] __tun_chr_ioctl+0x12be/0x3d20 [ 46.975551] tun_chr_ioctl+0x2a/0x40 [ 46.979235] do_vfs_ioctl+0x1b1/0x1530 [ 46.983092] SyS_ioctl+0x8f/0xc0 [ 46.986429] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 46.991151] [ 46.992747] Freed by task 2985: [ 46.995994] save_stack_trace+0x16/0x20 [ 46.999936] save_stack+0x43/0xd0 [ 47.003358] kasan_slab_free+0x71/0xc0 [ 47.007212] kfree+0xca/0x250 [ 47.010284] kvfree+0x36/0x60 [ 47.013361] free_netdev+0x2cf/0x360 [ 47.017043] __tun_chr_ioctl+0x2cf6/0x3d20 [ 47.021246] tun_chr_ioctl+0x2a/0x40 [ 47.024928] do_vfs_ioctl+0x1b1/0x1530 [ 47.028781] SyS_ioctl+0x8f/0xc0 [ 47.032119] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 47.036839] [ 47.038438] The buggy address belongs to the object at ffff8801ce2b8280 [ 47.038438] which belongs to the cache kmalloc-16384 of size 16384 [ 47.051408] The buggy address is located 13320 bytes inside of [ 47.051408] 16384-byte region [ffff8801ce2b8280, ffff8801ce2bc280) [ 47.063594] The buggy address belongs to the page: [ 47.068494] page:ffffea000738ae00 count:1 mapcount:0 mapping:ffff8801ce2b8280 index:0x0 compound_mapcount: 0 [ 47.078438] flags: 0x200000000008100(slab|head) [ 47.083077] raw: 0200000000008100 ffff8801ce2b8280 0000000000000000 0000000100000001 [ 47.090926] raw: ffffea0007554620 ffffea0007385c20 ffff8801dac02200 0000000000000000 [ 47.098774] page dumped because: kasan: bad access detected [ 47.104452] [ 47.106048] Memory state around the buggy address: [ 47.110946] ffff8801ce2bb580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.118273] ffff8801ce2bb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.125597] >ffff8801ce2bb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.132926] ^ [ 47.136520] ffff8801ce2bb700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.143846] ffff8801ce2bb780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.151175] ================================================================== [ 47.158501] Disabling lock debugging due to kernel taint [ 47.163913] Kernel panic - not syncing: panic_on_warn set ... [ 47.163913] [ 47.171238] CPU: 0 PID: 2985 Comm: syzkaller013726 Tainted: G B 4.13.0-mm1+ #7 [ 47.179689] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.189009] Call Trace: [ 47.191566] dump_stack+0x194/0x257 [ 47.195159] ? arch_local_irq_restore+0x53/0x53 [ 47.199794] ? vprintk_default+0x28/0x30 [ 47.203820] ? __internal_add_timer+0x200/0x2d0 [ 47.208454] panic+0x1e4/0x417 [ 47.211610] ? __warn+0x1d9/0x1d9 [ 47.215035] ? __internal_add_timer+0x275/0x2d0 [ 47.219667] kasan_end_report+0x50/0x50 [ 47.223604] kasan_report+0x137/0x340 [ 47.227371] __asan_report_store8_noabort+0x17/0x20 [ 47.232349] __internal_add_timer+0x275/0x2d0 [ 47.236809] ? calc_wheel_index+0x200/0x200 [ 47.241114] mod_timer+0x622/0x15b0 [ 47.244710] ? mod_timer_pending+0x14e0/0x14e0 [ 47.249260] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 47.254240] ? trace_hardirqs_on+0xd/0x10 [ 47.258354] ? _crng_backtrack_protect+0xd9/0x130 [ 47.263165] ? __lock_is_held+0xbc/0x140 [ 47.267193] ? __lockdep_init_map+0xe4/0x650 [ 47.271568] ? lockdep_init_map+0x3d/0x70 [ 47.275683] ? rcu_read_lock_sched_held+0x108/0x120 [ 47.280663] ? init_timer_key+0x126/0x3b0 [ 47.284775] ? try_to_del_timer_sync+0x120/0x120 [ 47.289505] ? round_jiffies_up+0xce/0x100 [ 47.293704] ? __round_jiffies_up_relative+0x150/0x150 [ 47.298944] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 47.303845] __tun_chr_ioctl+0x1b23/0x3d20 [ 47.308048] ? tun_chr_read_iter+0x1e0/0x1e0 [ 47.312437] ? lock_downgrade+0x990/0x990 [ 47.316566] ? check_same_owner+0x320/0x320 [ 47.320851] ? __handle_mm_fault+0x39c0/0x39c0 [ 47.325397] ? vmacache_find+0x61/0x270 [ 47.329338] ? tun_chr_compat_ioctl+0x30/0x30 [ 47.333796] tun_chr_ioctl+0x2a/0x40 [ 47.337473] ? tun_chr_ioctl+0x2a/0x40 [ 47.341328] do_vfs_ioctl+0x1b1/0x1530 [ 47.345184] ? ioctl_preallocate+0x2b0/0x2b0 [ 47.349562] ? selinux_capable+0x40/0x40 [ 47.353588] ? putname+0xf3/0x130 [ 47.357010] ? do_sys_open+0x320/0x6d0 [ 47.360869] ? security_file_ioctl+0x7d/0xb0 [ 47.365243] ? security_file_ioctl+0x89/0xb0 [ 47.369618] SyS_ioctl+0x8f/0xc0 [ 47.372954] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 47.377673] RIP: 0033:0x443d79 [ 47.380829] RSP: 002b:00007ffc0e02c258 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 47.388511] RAX: ffffffffffffffda RBX: f1ce4a65c3b97a7a RCX: 0000000000443d79 [ 47.395746] RDX: 0000000020927fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 47.402982] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 47.410216] R10: 0000000000000000 R11: 0000000000000202 R12: d7c29eea7c696697 [ 47.417456] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000