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-mmots-kasan-gce-7,10.128.15.204' (ECDSA) to the list of known hosts. executing program executing program executing program syzkaller login: [ 29.704049] ================================================================== [ 29.711497] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 29.718482] Write of size 8 at addr ffff8801ce2536c8 by task syzkaller609428/2984 [ 29.726072] [ 29.727673] CPU: 0 PID: 2984 Comm: syzkaller609428 Not tainted 4.13.0-mm1+ #7 [ 29.734915] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.744241] Call Trace: [ 29.746804] dump_stack+0x194/0x257 [ 29.750406] ? arch_local_irq_restore+0x53/0x53 [ 29.755048] ? show_regs_print_info+0x65/0x65 [ 29.759521] ? __kernel_text_address+0xae/0xe0 [ 29.764076] ? __internal_add_timer+0x275/0x2d0 [ 29.768718] print_address_description+0x73/0x250 [ 29.773532] ? __internal_add_timer+0x275/0x2d0 [ 29.778174] kasan_report+0x24e/0x340 [ 29.781950] __asan_report_store8_noabort+0x17/0x20 [ 29.786939] __internal_add_timer+0x275/0x2d0 [ 29.791410] ? calc_wheel_index+0x200/0x200 [ 29.795717] mod_timer+0x622/0x15b0 [ 29.799328] ? mod_timer_pending+0x14e0/0x14e0 [ 29.803883] ? __lock_is_held+0xbc/0x140 [ 29.807934] ? __lock_is_held+0xbc/0x140 [ 29.811971] ? __lockdep_init_map+0xe4/0x650 [ 29.816358] ? lockdep_init_map+0x3d/0x70 [ 29.820481] ? rcu_read_lock_sched_held+0x108/0x120 [ 29.825470] ? init_timer_key+0x126/0x3b0 [ 29.829595] ? try_to_del_timer_sync+0x120/0x120 [ 29.834323] ? round_jiffies_up+0xce/0x100 [ 29.838530] ? __round_jiffies_up_relative+0x150/0x150 [ 29.843779] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 29.848682] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 29.854201] __tun_chr_ioctl+0x1b23/0x3d20 [ 29.858422] ? tun_chr_read_iter+0x1e0/0x1e0 [ 29.862814] ? lock_downgrade+0x990/0x990 [ 29.866960] ? check_same_owner+0x320/0x320 [ 29.871257] ? __handle_mm_fault+0x39c0/0x39c0 [ 29.875811] ? vmacache_find+0x61/0x270 [ 29.879761] ? tun_chr_compat_ioctl+0x30/0x30 [ 29.884228] tun_chr_ioctl+0x2a/0x40 [ 29.887912] ? tun_chr_ioctl+0x2a/0x40 [ 29.891772] do_vfs_ioctl+0x1b1/0x1530 [ 29.895636] ? ioctl_preallocate+0x2b0/0x2b0 [ 29.900019] ? selinux_capable+0x40/0x40 [ 29.904052] ? putname+0xf3/0x130 [ 29.907482] ? do_sys_open+0x320/0x6d0 [ 29.911351] ? security_file_ioctl+0x7d/0xb0 [ 29.915728] ? security_file_ioctl+0x89/0xb0 [ 29.920113] SyS_ioctl+0x8f/0xc0 [ 29.923457] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 29.928184] RIP: 0033:0x443d99 [ 29.931346] RSP: 002b:00007fffc47bc298 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 29.939028] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d99 [ 29.946270] RDX: 000000002019dfd8 RSI: 00000000400454ca RDI: 0000000000000005 [ 29.953512] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 29.960753] R10: 0000000000000000 R11: 0000000000000202 R12: b1f43bc120dbbe94 [ 29.967994] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 29.975254] [ 29.976855] Allocated by task 2984: [ 29.980455] save_stack_trace+0x16/0x20 [ 29.984401] save_stack+0x43/0xd0 [ 29.987828] kasan_kmalloc+0xad/0xe0 [ 29.991514] __kmalloc_node+0x47/0x70 [ 29.995298] kvmalloc_node+0x64/0xd0 [ 29.998986] alloc_netdev_mqs+0x16e/0xed0 [ 30.003106] __tun_chr_ioctl+0x12be/0x3d20 [ 30.007309] tun_chr_ioctl+0x2a/0x40 [ 30.010994] do_vfs_ioctl+0x1b1/0x1530 [ 30.014855] SyS_ioctl+0x8f/0xc0 [ 30.018198] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 30.022938] [ 30.024537] Freed by task 2984: [ 30.027791] save_stack_trace+0x16/0x20 [ 30.031736] save_stack+0x43/0xd0 [ 30.035158] kasan_slab_free+0x71/0xc0 [ 30.039013] kfree+0xca/0x250 [ 30.042090] kvfree+0x36/0x60 [ 30.045169] free_netdev+0x2cf/0x360 [ 30.048850] __tun_chr_ioctl+0x2cf6/0x3d20 [ 30.053052] tun_chr_ioctl+0x2a/0x40 [ 30.056734] do_vfs_ioctl+0x1b1/0x1530 [ 30.060591] SyS_ioctl+0x8f/0xc0 [ 30.063926] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 30.068647] [ 30.070246] The buggy address belongs to the object at ffff8801ce2502c0 [ 30.070246] which belongs to the cache kmalloc-16384 of size 16384 [ 30.083216] The buggy address is located 13320 bytes inside of [ 30.083216] 16384-byte region [ffff8801ce2502c0, ffff8801ce2542c0) [ 30.095407] The buggy address belongs to the page: [ 30.100304] page:ffffea0007389400 count:1 mapcount:0 mapping:ffff8801ce2502c0 index:0x0 compound_mapcount: 0 [ 30.110248] flags: 0x200000000008100(slab|head) [ 30.114887] raw: 0200000000008100 ffff8801ce2502c0 0000000000000000 0000000100000001 [ 30.122736] raw: ffffea0007386e20 ffffea0007384820 ffff8801dac02200 0000000000000000 [ 30.130583] page dumped because: kasan: bad access detected [ 30.136259] [ 30.137854] Memory state around the buggy address: [ 30.142750] ffff8801ce253580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.150076] ffff8801ce253600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.157405] >ffff8801ce253680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.164731] ^ [ 30.170425] ffff8801ce253700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.177753] ffff8801ce253780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.185078] ================================================================== [ 30.192411] Disabling lock debugging due to kernel taint [ 30.197824] Kernel panic - not syncing: panic_on_warn set ... [ 30.197824] [ 30.205153] CPU: 0 PID: 2984 Comm: syzkaller609428 Tainted: G B 4.13.0-mm1+ #7 [ 30.213604] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.222922] Call Trace: [ 30.225476] dump_stack+0x194/0x257 [ 30.229072] ? arch_local_irq_restore+0x53/0x53 [ 30.233706] ? vprintk_default+0x28/0x30 [ 30.237734] ? __internal_add_timer+0x200/0x2d0 [ 30.242370] panic+0x1e4/0x417 [ 30.245530] ? __warn+0x1d9/0x1d9 [ 30.248955] ? __internal_add_timer+0x275/0x2d0 [ 30.253590] kasan_end_report+0x50/0x50 [ 30.257527] kasan_report+0x137/0x340 [ 30.261293] __asan_report_store8_noabort+0x17/0x20 [ 30.266273] __internal_add_timer+0x275/0x2d0 [ 30.270733] ? calc_wheel_index+0x200/0x200 [ 30.275022] mod_timer+0x622/0x15b0 [ 30.278618] ? mod_timer_pending+0x14e0/0x14e0 [ 30.283164] ? __lock_is_held+0xbc/0x140 [ 30.287199] ? __lock_is_held+0xbc/0x140 [ 30.291229] ? __lockdep_init_map+0xe4/0x650 [ 30.295601] ? lockdep_init_map+0x3d/0x70 [ 30.299716] ? rcu_read_lock_sched_held+0x108/0x120 [ 30.304696] ? init_timer_key+0x126/0x3b0 [ 30.308809] ? try_to_del_timer_sync+0x120/0x120 [ 30.313528] ? round_jiffies_up+0xce/0x100 [ 30.317727] ? __round_jiffies_up_relative+0x150/0x150 [ 30.322966] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 30.327861] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 30.333366] __tun_chr_ioctl+0x1b23/0x3d20 [ 30.337571] ? tun_chr_read_iter+0x1e0/0x1e0 [ 30.341950] ? lock_downgrade+0x990/0x990 [ 30.346076] ? check_same_owner+0x320/0x320 [ 30.350360] ? __handle_mm_fault+0x39c0/0x39c0 [ 30.354908] ? vmacache_find+0x61/0x270 [ 30.358847] ? tun_chr_compat_ioctl+0x30/0x30 [ 30.363306] tun_chr_ioctl+0x2a/0x40 [ 30.366983] ? tun_chr_ioctl+0x2a/0x40 [ 30.370836] do_vfs_ioctl+0x1b1/0x1530 [ 30.374690] ? ioctl_preallocate+0x2b0/0x2b0 [ 30.379063] ? selinux_capable+0x40/0x40 [ 30.383090] ? putname+0xf3/0x130 [ 30.386507] ? do_sys_open+0x320/0x6d0 [ 30.390363] ? security_file_ioctl+0x7d/0xb0 [ 30.394737] ? security_file_ioctl+0x89/0xb0 [ 30.399110] SyS_ioctl+0x8f/0xc0 [ 30.402442] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 30.407160] RIP: 0033:0x443d99 [ 30.410315] RSP: 002b:00007fffc47bc298 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 30.417986] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d99 [ 30.425220] RDX: 000000002019dfd8 RSI: 00000000400454ca RDI: 0000000000000005 [ 30.432455] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 30.439689] R10: 0000000000000000 R11: 0000000000000202 R12: b1f43bc120dbbe94 [ 30.446924] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000