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-2,10.128.15.231' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 33.477051] ================================================================== [ 33.478145] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 33.479066] Write of size 8 at addr ffff8801d2193500 by task syzkaller849583/2985 [ 33.480062] [ 33.480298] CPU: 1 PID: 2985 Comm: syzkaller849583 Not tainted 4.14.0-rc5+ #142 [ 33.481272] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.482490] Call Trace: [ 33.482848] dump_stack+0x194/0x257 [ 33.483340] ? arch_local_irq_restore+0x53/0x53 [ 33.483981] ? show_regs_print_info+0x65/0x65 [ 33.484584] ? __kernel_text_address+0xd/0x40 [ 33.485185] ? __internal_add_timer+0x275/0x2d0 [ 33.485810] print_address_description+0x73/0x250 [ 33.486454] ? __internal_add_timer+0x275/0x2d0 [ 33.487095] kasan_report+0x25b/0x340 [ 33.487611] __asan_report_store8_noabort+0x17/0x20 [ 33.488275] __internal_add_timer+0x275/0x2d0 [ 33.488881] ? calc_wheel_index+0x200/0x200 [ 33.489486] mod_timer+0x622/0x15b0 [ 33.489985] ? mod_timer_pending+0x14e0/0x14e0 [ 33.490596] ? __lock_is_held+0xb6/0x140 [ 33.491154] ? __lock_is_held+0xb6/0x140 [ 33.491705] ? __lockdep_init_map+0xe4/0x650 [ 33.492315] ? lockdep_init_map+0x9/0x10 [ 33.492859] ? init_timer_key+0x126/0x3b0 [ 33.493418] ? try_to_del_timer_sync+0x120/0x120 [ 33.494053] ? round_jiffies_up+0xce/0x100 [ 33.494621] ? __round_jiffies_up_relative+0x150/0x150 [ 33.495320] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.495989] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 33.496730] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.497317] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.501690] ? find_held_lock+0x35/0x1d0 [ 33.505726] ? __do_page_fault+0x64c/0xd60 [ 33.509929] ? lock_downgrade+0x990/0x990 [ 33.514050] ? handle_mm_fault+0x410/0x8d0 [ 33.518264] ? check_same_owner+0x320/0x320 [ 33.522552] ? up_read+0x1a/0x40 [ 33.525885] ? __do_page_fault+0x3d6/0xd60 [ 33.530090] ? tun_chr_compat_ioctl+0x30/0x30 [ 33.534552] tun_chr_ioctl+0x2a/0x40 [ 33.538232] ? tun_chr_ioctl+0x2a/0x40 [ 33.542087] do_vfs_ioctl+0x1b1/0x1520 [ 33.545946] ? ioctl_preallocate+0x2b0/0x2b0 [ 33.550325] ? selinux_capable+0x40/0x40 [ 33.554354] ? putname+0xf3/0x130 [ 33.557782] ? do_sys_open+0x320/0x6d0 [ 33.561645] ? security_file_ioctl+0x89/0xb0 [ 33.566026] SyS_ioctl+0x8f/0xc0 [ 33.569364] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.574083] RIP: 0033:0x443d79 [ 33.577238] RSP: 002b:00007ffc87205178 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 33.584910] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d79 [ 33.592144] RDX: 00000000209fa000 RSI: 00000000400454ca RDI: 0000000000000004 [ 33.599378] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 33.606614] R10: 0000000000000000 R11: 0000000000000206 R12: 6c92fab866033a3b [ 33.613851] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 33.621102] [ 33.622695] Allocated by task 2985: [ 33.626289] save_stack_trace+0x16/0x20 [ 33.630228] save_stack+0x43/0xd0 [ 33.633646] kasan_kmalloc+0xad/0xe0 [ 33.637324] __kmalloc_node+0x47/0x70 [ 33.641089] kvmalloc_node+0x64/0xd0 [ 33.644771] alloc_netdev_mqs+0x16e/0xed0 [ 33.648882] __tun_chr_ioctl+0x12b2/0x3d20 [ 33.653081] tun_chr_ioctl+0x2a/0x40 [ 33.656759] do_vfs_ioctl+0x1b1/0x1520 [ 33.660612] SyS_ioctl+0x8f/0xc0 [ 33.663946] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.668667] [ 33.670260] Freed by task 2985: [ 33.673504] save_stack_trace+0x16/0x20 [ 33.677442] save_stack+0x43/0xd0 [ 33.680860] kasan_slab_free+0x71/0xc0 [ 33.684713] kfree+0xca/0x250 [ 33.687784] kvfree+0x36/0x60 [ 33.690859] free_netdev+0x2cf/0x360 [ 33.694540] __tun_chr_ioctl+0x2cea/0x3d20 [ 33.698739] tun_chr_ioctl+0x2a/0x40 [ 33.702420] do_vfs_ioctl+0x1b1/0x1520 [ 33.706270] SyS_ioctl+0x8f/0xc0 [ 33.709600] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.714318] [ 33.715913] The buggy address belongs to the object at ffff8801d21901c0 [ 33.715913] which belongs to the cache kmalloc-16384 of size 16384 [ 33.728880] The buggy address is located 13120 bytes inside of [ 33.728880] 16384-byte region [ffff8801d21901c0, ffff8801d21941c0) [ 33.741065] The buggy address belongs to the page: [ 33.745959] page:ffffea0007486400 count:1 mapcount:0 mapping:ffff8801d21901c0 index:0x0 compound_mapcount: 0 [ 33.755894] flags: 0x200000000008100(slab|head) [ 33.760530] raw: 0200000000008100 ffff8801d21901c0 0000000000000000 0000000100000001 [ 33.768379] raw: ffffea0007658620 ffffea0007478220 ffff8801dac02200 0000000000000000 [ 33.776221] page dumped because: kasan: bad access detected [ 33.781893] [ 33.783488] Memory state around the buggy address: [ 33.788381] ffff8801d2193400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.795705] ffff8801d2193480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.803029] >ffff8801d2193500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.810351] ^ [ 33.813681] ffff8801d2193580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.821006] ffff8801d2193600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.828327] ================================================================== [ 33.835648] Disabling lock debugging due to kernel taint [ 33.841060] Kernel panic - not syncing: panic_on_warn set ... [ 33.841060] [ 33.848384] CPU: 1 PID: 2985 Comm: syzkaller849583 Tainted: G B 4.14.0-rc5+ #142 [ 33.857006] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.866323] Call Trace: [ 33.868875] dump_stack+0x194/0x257 [ 33.872466] ? arch_local_irq_restore+0x53/0x53 [ 33.877097] ? kasan_end_report+0x32/0x50 [ 33.881209] ? lock_downgrade+0x990/0x990 [ 33.885323] ? __internal_add_timer+0x1f0/0x2d0 [ 33.889960] panic+0x1e4/0x417 [ 33.893118] ? __warn+0x1d9/0x1d9 [ 33.896542] ? __internal_add_timer+0x275/0x2d0 [ 33.901175] kasan_end_report+0x50/0x50 [ 33.905112] kasan_report+0x144/0x340 [ 33.908880] __asan_report_store8_noabort+0x17/0x20 [ 33.913860] __internal_add_timer+0x275/0x2d0 [ 33.918321] ? calc_wheel_index+0x200/0x200 [ 33.922611] mod_timer+0x622/0x15b0 [ 33.926206] ? mod_timer_pending+0x14e0/0x14e0 [ 33.930753] ? __lock_is_held+0xb6/0x140 [ 33.934785] ? __lock_is_held+0xb6/0x140 [ 33.938815] ? __lockdep_init_map+0xe4/0x650 [ 33.943189] ? lockdep_init_map+0x9/0x10 [ 33.947211] ? init_timer_key+0x126/0x3b0 [ 33.951323] ? try_to_del_timer_sync+0x120/0x120 [ 33.956044] ? round_jiffies_up+0xce/0x100 [ 33.960242] ? __round_jiffies_up_relative+0x150/0x150 [ 33.965482] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.970376] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 33.975881] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.980084] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.984454] ? find_held_lock+0x35/0x1d0 [ 33.988483] ? __do_page_fault+0x64c/0xd60 [ 33.992683] ? lock_downgrade+0x990/0x990 [ 33.996799] ? handle_mm_fault+0x410/0x8d0 [ 34.001007] ? check_same_owner+0x320/0x320 [ 34.005291] ? up_read+0x1a/0x40 [ 34.008622] ? __do_page_fault+0x3d6/0xd60 [ 34.012825] ? tun_chr_compat_ioctl+0x30/0x30 [ 34.017284] tun_chr_ioctl+0x2a/0x40 [ 34.020961] ? tun_chr_ioctl+0x2a/0x40 [ 34.024816] do_vfs_ioctl+0x1b1/0x1520 [ 34.028670] ? ioctl_preallocate+0x2b0/0x2b0 [ 34.033042] ? selinux_capable+0x40/0x40 [ 34.037069] ? putname+0xf3/0x130 [ 34.040488] ? do_sys_open+0x320/0x6d0 [ 34.044344] ? security_file_ioctl+0x89/0xb0 [ 34.048740] SyS_ioctl+0x8f/0xc0 [ 34.052082] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 34.056801] RIP: 0033:0x443d79 [ 34.059956] RSP: 002b:00007ffc87205178 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 34.067626] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d79 [ 34.074860] RDX: 00000000209fa000 RSI: 00000000400454ca RDI: 0000000000000004 [ 34.082099] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 34.089340] R10: 0000000000000000 R11: 0000000000000206 R12: 6c92fab866033a3b [ 34.096574] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 34.104189] Dumping ftrace buffer: [ 34.107700] (ftrace buffer empty) [ 34.111379] Kernel Offset: disabled [ 34.114973] Rebooting in 86400 seconds..