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-3,10.128.0.49' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 46.540720] ================================================================== [ 46.541853] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 46.542791] Write of size 8 at addr ffff8801d1f9b600 by task syzkaller022518/2985 [ 46.543786] [ 46.544021] CPU: 0 PID: 2985 Comm: syzkaller022518 Not tainted 4.14.0-rc5+ #141 [ 46.544995] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.546212] Call Trace: [ 46.546572] dump_stack+0x194/0x257 [ 46.547062] ? arch_local_irq_restore+0x53/0x53 [ 46.547685] ? show_regs_print_info+0x65/0x65 [ 46.548288] ? __kernel_text_address+0xd/0x40 [ 46.548887] ? __internal_add_timer+0x275/0x2d0 [ 46.549510] print_address_description+0x73/0x250 [ 46.550153] ? __internal_add_timer+0x275/0x2d0 [ 46.550776] kasan_report+0x25b/0x340 [ 46.551290] __asan_report_store8_noabort+0x17/0x20 [ 46.551972] __internal_add_timer+0x275/0x2d0 [ 46.552574] ? calc_wheel_index+0x200/0x200 [ 46.553160] mod_timer+0x622/0x15b0 [ 46.553667] ? mod_timer_pending+0x14e0/0x14e0 [ 46.554281] ? __lock_is_held+0xb6/0x140 [ 46.554837] ? __lock_is_held+0xb6/0x140 [ 46.555402] ? __lockdep_init_map+0xe4/0x650 [ 46.555992] ? lockdep_init_map+0x9/0x10 [ 46.556533] ? init_timer_key+0x126/0x3b0 [ 46.557090] ? try_to_del_timer_sync+0x120/0x120 [ 46.557723] ? round_jiffies_up+0xce/0x100 [ 46.558289] ? __round_jiffies_up_relative+0x150/0x150 [ 46.559007] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 46.559677] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 46.560442] __tun_chr_ioctl+0x1b17/0x3d20 [ 46.561028] ? unwind_get_return_address+0x24/0xa0 [ 46.565934] ? tun_chr_read_iter+0x1e0/0x1e0 [ 46.570312] ? putname+0xee/0x130 [ 46.573732] ? save_stack+0xa3/0xd0 [ 46.577329] ? save_stack_trace+0x16/0x20 [ 46.581443] ? save_stack+0x43/0xd0 [ 46.585046] ? kasan_slab_free+0x71/0xc0 [ 46.589072] ? kmem_cache_free+0x77/0x280 [ 46.593185] ? putname+0xee/0x130 [ 46.596612] ? __lock_is_held+0xb6/0x140 [ 46.600658] ? check_same_owner+0x320/0x320 [ 46.604953] ? tun_chr_compat_ioctl+0x30/0x30 [ 46.609414] tun_chr_ioctl+0x2a/0x40 [ 46.613093] ? tun_chr_ioctl+0x2a/0x40 [ 46.616951] do_vfs_ioctl+0x1b1/0x1520 [ 46.620810] ? ioctl_preallocate+0x2b0/0x2b0 [ 46.625188] ? selinux_capable+0x40/0x40 [ 46.629217] ? putname+0xf3/0x130 [ 46.632642] ? do_sys_open+0x320/0x6d0 [ 46.636507] ? security_file_ioctl+0x89/0xb0 [ 46.640885] SyS_ioctl+0x8f/0xc0 [ 46.644225] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 46.648944] RIP: 0033:0x443d79 [ 46.652116] RSP: 002b:00007ffd7fe1f1c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 46.659792] RAX: ffffffffffffffda RBX: 6fe59629500f111b RCX: 0000000000443d79 [ 46.667027] RDX: 00000000204c8fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 46.674264] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 46.681500] R10: 0000000000000000 R11: 0000000000000202 R12: c125046415db6c3f [ 46.688734] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 46.695987] [ 46.697580] Allocated by task 2985: [ 46.701172] save_stack_trace+0x16/0x20 [ 46.705109] save_stack+0x43/0xd0 [ 46.708528] kasan_kmalloc+0xad/0xe0 [ 46.712205] __kmalloc_node+0x47/0x70 [ 46.715971] kvmalloc_node+0x64/0xd0 [ 46.719652] alloc_netdev_mqs+0x16e/0xed0 [ 46.723763] __tun_chr_ioctl+0x12b2/0x3d20 [ 46.727960] tun_chr_ioctl+0x2a/0x40 [ 46.731639] do_vfs_ioctl+0x1b1/0x1520 [ 46.735489] SyS_ioctl+0x8f/0xc0 [ 46.738820] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 46.743536] [ 46.745131] Freed by task 2985: [ 46.748374] save_stack_trace+0x16/0x20 [ 46.752310] save_stack+0x43/0xd0 [ 46.755726] kasan_slab_free+0x71/0xc0 [ 46.759577] kfree+0xca/0x250 [ 46.762646] kvfree+0x36/0x60 [ 46.765716] free_netdev+0x2cf/0x360 [ 46.769395] __tun_chr_ioctl+0x2cea/0x3d20 [ 46.773592] tun_chr_ioctl+0x2a/0x40 [ 46.777269] do_vfs_ioctl+0x1b1/0x1520 [ 46.781124] SyS_ioctl+0x8f/0xc0 [ 46.784455] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 46.789177] [ 46.790788] The buggy address belongs to the object at ffff8801d1f982c0 [ 46.790788] which belongs to the cache kmalloc-16384 of size 16384 [ 46.804103] The buggy address is located 13120 bytes inside of [ 46.804103] 16384-byte region [ffff8801d1f982c0, ffff8801d1f9c2c0) [ 46.816290] The buggy address belongs to the page: [ 46.821186] page:ffffea000747e600 count:1 mapcount:0 mapping:ffff8801d1f982c0 index:0x0 compound_mapcount: 0 [ 46.831122] flags: 0x200000000008100(slab|head) [ 46.835759] raw: 0200000000008100 ffff8801d1f982c0 0000000000000000 0000000100000001 [ 46.843607] raw: ffffea0007646620 ffffea000747a620 ffff8801dac02200 0000000000000000 [ 46.851452] page dumped because: kasan: bad access detected [ 46.857127] [ 46.858718] Memory state around the buggy address: [ 46.863613] ffff8801d1f9b500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.870936] ffff8801d1f9b580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.878259] >ffff8801d1f9b600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.885582] ^ [ 46.888910] ffff8801d1f9b680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.896234] ffff8801d1f9b700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.903556] ================================================================== [ 46.910879] Disabling lock debugging due to kernel taint [ 46.916291] Kernel panic - not syncing: panic_on_warn set ... [ 46.916291] [ 46.923617] CPU: 0 PID: 2985 Comm: syzkaller022518 Tainted: G B 4.14.0-rc5+ #141 [ 46.932244] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.941560] Call Trace: [ 46.944116] dump_stack+0x194/0x257 [ 46.947711] ? arch_local_irq_restore+0x53/0x53 [ 46.952341] ? kasan_end_report+0x32/0x50 [ 46.956457] ? lock_downgrade+0x990/0x990 [ 46.960571] ? __internal_add_timer+0x1f0/0x2d0 [ 46.965207] panic+0x1e4/0x417 [ 46.968364] ? __warn+0x1d9/0x1d9 [ 46.971787] ? __internal_add_timer+0x275/0x2d0 [ 46.976418] kasan_end_report+0x50/0x50 [ 46.980357] kasan_report+0x144/0x340 [ 46.984127] __asan_report_store8_noabort+0x17/0x20 [ 46.989109] __internal_add_timer+0x275/0x2d0 [ 46.993570] ? calc_wheel_index+0x200/0x200 [ 46.997877] mod_timer+0x622/0x15b0 [ 47.001484] ? mod_timer_pending+0x14e0/0x14e0 [ 47.006029] ? __lock_is_held+0xb6/0x140 [ 47.010078] ? __lock_is_held+0xb6/0x140 [ 47.014106] ? __lockdep_init_map+0xe4/0x650 [ 47.018480] ? lockdep_init_map+0x9/0x10 [ 47.022504] ? init_timer_key+0x126/0x3b0 [ 47.026616] ? try_to_del_timer_sync+0x120/0x120 [ 47.031341] ? round_jiffies_up+0xce/0x100 [ 47.035540] ? __round_jiffies_up_relative+0x150/0x150 [ 47.040781] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 47.045675] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 47.051178] __tun_chr_ioctl+0x1b17/0x3d20 [ 47.055378] ? unwind_get_return_address+0x24/0xa0 [ 47.060275] ? tun_chr_read_iter+0x1e0/0x1e0 [ 47.064647] ? putname+0xee/0x130 [ 47.068065] ? save_stack+0xa3/0xd0 [ 47.071659] ? save_stack_trace+0x16/0x20 [ 47.075770] ? save_stack+0x43/0xd0 [ 47.079367] ? kasan_slab_free+0x71/0xc0 [ 47.083397] ? kmem_cache_free+0x77/0x280 [ 47.087510] ? putname+0xee/0x130 [ 47.090931] ? __lock_is_held+0xb6/0x140 [ 47.094965] ? check_same_owner+0x320/0x320 [ 47.099254] ? tun_chr_compat_ioctl+0x30/0x30 [ 47.103715] tun_chr_ioctl+0x2a/0x40 [ 47.107395] ? tun_chr_ioctl+0x2a/0x40 [ 47.111251] do_vfs_ioctl+0x1b1/0x1520 [ 47.115104] ? ioctl_preallocate+0x2b0/0x2b0 [ 47.119480] ? selinux_capable+0x40/0x40 [ 47.123507] ? putname+0xf3/0x130 [ 47.126927] ? do_sys_open+0x320/0x6d0 [ 47.130787] ? security_file_ioctl+0x89/0xb0 [ 47.135163] SyS_ioctl+0x8f/0xc0 [ 47.138497] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 47.143215] RIP: 0033:0x443d79 [ 47.146369] RSP: 002b:00007ffd7fe1f1c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 47.154041] RAX: ffffffffffffffda RBX: 6fe59629500f111b RCX: 0000000000443d79 [ 47.161281] RDX: 00000000204c8fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 47.168515] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 47.175749] R10: 0000000000000000 R11: 0000000000000202 R12: c125046415db6c3f [ 47.182983] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000