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-3,10.128.15.225' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 33.018606] ================================================================== [ 33.019728] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 33.020650] Write of size 8 at addr ffff8801d1a73600 by task syzkaller398821/2994 [ 33.021645] [ 33.021878] CPU: 1 PID: 2994 Comm: syzkaller398821 Not tainted 4.14.0-rc5+ #140 [ 33.022852] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.024070] Call Trace: [ 33.024429] dump_stack+0x194/0x257 [ 33.024922] ? arch_local_irq_restore+0x53/0x53 [ 33.025552] ? show_regs_print_info+0x65/0x65 [ 33.026156] ? __kernel_text_address+0xd/0x40 [ 33.026757] ? __internal_add_timer+0x275/0x2d0 [ 33.027381] print_address_description+0x73/0x250 [ 33.028024] ? __internal_add_timer+0x275/0x2d0 [ 33.028661] kasan_report+0x25b/0x340 [ 33.029174] __asan_report_store8_noabort+0x17/0x20 [ 33.029839] __internal_add_timer+0x275/0x2d0 [ 33.030440] ? calc_wheel_index+0x200/0x200 [ 33.031028] mod_timer+0x622/0x15b0 [ 33.031526] ? mod_timer_pending+0x14e0/0x14e0 [ 33.032137] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 33.032809] ? trace_hardirqs_on+0xd/0x10 [ 33.033368] ? _crng_backtrack_protect+0xd9/0x130 [ 33.034019] ? __lock_is_held+0xb6/0x140 [ 33.034568] ? __lockdep_init_map+0xe4/0x650 [ 33.035159] ? lockdep_init_map+0x9/0x10 [ 33.035704] ? init_timer_key+0x126/0x3b0 [ 33.036260] ? try_to_del_timer_sync+0x120/0x120 [ 33.036914] ? round_jiffies_up+0xce/0x100 [ 33.037480] ? __round_jiffies_up_relative+0x150/0x150 [ 33.038198] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.038862] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.043072] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.047446] ? find_held_lock+0x35/0x1d0 [ 33.051481] ? __do_page_fault+0x64c/0xd60 [ 33.055681] ? lock_downgrade+0x990/0x990 [ 33.059806] ? handle_mm_fault+0x410/0x8d0 [ 33.064021] ? check_same_owner+0x320/0x320 [ 33.068306] ? up_read+0x1a/0x40 [ 33.071640] ? __do_page_fault+0x3d6/0xd60 [ 33.075842] ? tun_chr_compat_ioctl+0x30/0x30 [ 33.080302] tun_chr_ioctl+0x2a/0x40 [ 33.083982] ? tun_chr_ioctl+0x2a/0x40 [ 33.087839] do_vfs_ioctl+0x1b1/0x1520 [ 33.091697] ? ioctl_preallocate+0x2b0/0x2b0 [ 33.096074] ? selinux_capable+0x40/0x40 [ 33.100102] ? putname+0xf3/0x130 [ 33.103525] ? do_sys_open+0x320/0x6d0 [ 33.107388] ? security_file_ioctl+0x89/0xb0 [ 33.111766] SyS_ioctl+0x8f/0xc0 [ 33.115115] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.119841] RIP: 0033:0x443de9 [ 33.122997] RSP: 002b:00007ffdfd503238 EFLAGS: 00000207 ORIG_RAX: 0000000000000010 [ 33.130672] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443de9 [ 33.137908] RDX: 00000000206b2fd8 RSI: 00000000400454ca RDI: 0000000000000006 [ 33.145144] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 33.152380] R10: 0000000000000000 R11: 0000000000000207 R12: e4ed13bb0248f101 [ 33.159618] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 33.166872] [ 33.168467] Allocated by task 2994: [ 33.172062] save_stack_trace+0x16/0x20 [ 33.176003] save_stack+0x43/0xd0 [ 33.179422] kasan_kmalloc+0xad/0xe0 [ 33.183100] __kmalloc_node+0x47/0x70 [ 33.186865] kvmalloc_node+0x64/0xd0 [ 33.190544] alloc_netdev_mqs+0x16e/0xed0 [ 33.194656] __tun_chr_ioctl+0x12b2/0x3d20 [ 33.198856] tun_chr_ioctl+0x2a/0x40 [ 33.202536] do_vfs_ioctl+0x1b1/0x1520 [ 33.206386] SyS_ioctl+0x8f/0xc0 [ 33.209719] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.214435] [ 33.216025] Freed by task 2994: [ 33.219268] save_stack_trace+0x16/0x20 [ 33.223206] save_stack+0x43/0xd0 [ 33.226621] kasan_slab_free+0x71/0xc0 [ 33.230478] kfree+0xca/0x250 [ 33.233551] kvfree+0x36/0x60 [ 33.236622] free_netdev+0x2cf/0x360 [ 33.240300] __tun_chr_ioctl+0x2cea/0x3d20 [ 33.244498] tun_chr_ioctl+0x2a/0x40 [ 33.248176] do_vfs_ioctl+0x1b1/0x1520 [ 33.252028] SyS_ioctl+0x8f/0xc0 [ 33.255359] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.260076] [ 33.261672] The buggy address belongs to the object at ffff8801d1a702c0 [ 33.261672] which belongs to the cache kmalloc-16384 of size 16384 [ 33.274640] The buggy address is located 13120 bytes inside of [ 33.274640] 16384-byte region [ffff8801d1a702c0, ffff8801d1a742c0) [ 33.286828] The buggy address belongs to the page: [ 33.291724] page:ffffea0007469c00 count:1 mapcount:0 mapping:ffff8801d1a702c0 index:0x0 compound_mapcount: 0 [ 33.301656] flags: 0x200000000008100(slab|head) [ 33.306292] raw: 0200000000008100 ffff8801d1a702c0 0000000000000000 0000000100000001 [ 33.314136] raw: ffffea0006ff2a20 ffffea0007472820 ffff8801dac02200 0000000000000000 [ 33.321975] page dumped because: kasan: bad access detected [ 33.327646] [ 33.329237] Memory state around the buggy address: [ 33.334128] ffff8801d1a73500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.341453] ffff8801d1a73580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.348776] >ffff8801d1a73600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.356095] ^ [ 33.359426] ffff8801d1a73680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.366747] ffff8801d1a73700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.374068] ================================================================== [ 33.381389] Disabling lock debugging due to kernel taint [ 33.386803] Kernel panic - not syncing: panic_on_warn set ... [ 33.386803] [ 33.394129] CPU: 1 PID: 2994 Comm: syzkaller398821 Tainted: G B 4.14.0-rc5+ #140 [ 33.402750] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.412068] Call Trace: [ 33.414622] dump_stack+0x194/0x257 [ 33.418214] ? arch_local_irq_restore+0x53/0x53 [ 33.422848] ? kasan_end_report+0x32/0x50 [ 33.426961] ? lock_downgrade+0x990/0x990 [ 33.431075] ? __internal_add_timer+0x1d0/0x2d0 [ 33.435708] panic+0x1e4/0x417 [ 33.438866] ? __warn+0x1d9/0x1d9 [ 33.442287] ? __internal_add_timer+0x275/0x2d0 [ 33.446919] kasan_end_report+0x50/0x50 [ 33.450854] kasan_report+0x144/0x340 [ 33.454620] __asan_report_store8_noabort+0x17/0x20 [ 33.459598] __internal_add_timer+0x275/0x2d0 [ 33.464056] ? calc_wheel_index+0x200/0x200 [ 33.468343] mod_timer+0x622/0x15b0 [ 33.471937] ? mod_timer_pending+0x14e0/0x14e0 [ 33.476479] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 33.481459] ? trace_hardirqs_on+0xd/0x10 [ 33.485573] ? _crng_backtrack_protect+0xd9/0x130 [ 33.490380] ? __lock_is_held+0xb6/0x140 [ 33.494406] ? __lockdep_init_map+0xe4/0x650 [ 33.498778] ? lockdep_init_map+0x9/0x10 [ 33.502802] ? init_timer_key+0x126/0x3b0 [ 33.506913] ? try_to_del_timer_sync+0x120/0x120 [ 33.511632] ? round_jiffies_up+0xce/0x100 [ 33.515827] ? __round_jiffies_up_relative+0x150/0x150 [ 33.521068] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.525964] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.530165] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.534540] ? find_held_lock+0x35/0x1d0 [ 33.538567] ? __do_page_fault+0x64c/0xd60 [ 33.542764] ? lock_downgrade+0x990/0x990 [ 33.546880] ? handle_mm_fault+0x410/0x8d0 [ 33.551087] ? check_same_owner+0x320/0x320 [ 33.555370] ? up_read+0x1a/0x40 [ 33.558698] ? __do_page_fault+0x3d6/0xd60 [ 33.562894] ? tun_chr_compat_ioctl+0x30/0x30 [ 33.567350] tun_chr_ioctl+0x2a/0x40 [ 33.571025] ? tun_chr_ioctl+0x2a/0x40 [ 33.574876] do_vfs_ioctl+0x1b1/0x1520 [ 33.578728] ? ioctl_preallocate+0x2b0/0x2b0 [ 33.583106] ? selinux_capable+0x40/0x40 [ 33.587129] ? putname+0xf3/0x130 [ 33.590548] ? do_sys_open+0x320/0x6d0 [ 33.594403] ? security_file_ioctl+0x89/0xb0 [ 33.598774] SyS_ioctl+0x8f/0xc0 [ 33.602106] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.606825] RIP: 0033:0x443de9 [ 33.609976] RSP: 002b:00007ffdfd503238 EFLAGS: 00000207 ORIG_RAX: 0000000000000010 [ 33.617644] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443de9 [ 33.624876] RDX: 00000000206b2fd8 RSI: 00000000400454ca RDI: 0000000000000006 [ 33.632109] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 33.639342] R10: 0000000000000000 R11: 0000000000000207 R12: e4ed13bb0248f101 [ 33.646574] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000