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-0,10.128.0.10' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 41.117033] ================================================================== [ 41.118241] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 41.119182] Write of size 8 at addr ffff8801d2173600 by task syzkaller615990/2976 [ 41.120181] [ 41.120418] CPU: 1 PID: 2976 Comm: syzkaller615990 Not tainted 4.14.0-rc5+ #137 [ 41.121394] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.122670] Call Trace: [ 41.123030] dump_stack+0x194/0x257 [ 41.123522] ? arch_local_irq_restore+0x53/0x53 [ 41.124147] ? show_regs_print_info+0x65/0x65 [ 41.124764] ? __kernel_text_address+0xd/0x40 [ 41.125364] ? __internal_add_timer+0x275/0x2d0 [ 41.125989] print_address_description+0x73/0x250 [ 41.126634] ? __internal_add_timer+0x275/0x2d0 [ 41.127257] kasan_report+0x25b/0x340 [ 41.127773] __asan_report_store8_noabort+0x17/0x20 [ 41.128487] __internal_add_timer+0x275/0x2d0 [ 41.129088] ? calc_wheel_index+0x200/0x200 [ 41.129677] mod_timer+0x622/0x15b0 [ 41.130187] ? mod_timer_pending+0x14e0/0x14e0 [ 41.130837] ? __lock_is_held+0xb6/0x140 [ 41.131395] ? __lock_is_held+0xb6/0x140 [ 41.131945] ? __lockdep_init_map+0xe4/0x650 [ 41.132538] ? lockdep_init_map+0x9/0x10 [ 41.133081] ? init_timer_key+0x126/0x3b0 [ 41.133641] ? try_to_del_timer_sync+0x120/0x120 [ 41.134280] ? round_jiffies_up+0xce/0x100 [ 41.134862] ? __round_jiffies_up_relative+0x150/0x150 [ 41.135563] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 41.136220] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 41.136990] __tun_chr_ioctl+0x1b17/0x3d20 [ 41.139943] ? tun_chr_read_iter+0x1e0/0x1e0 [ 41.144316] ? find_held_lock+0x35/0x1d0 [ 41.148356] ? __do_page_fault+0x64c/0xd60 [ 41.152560] ? lock_downgrade+0x990/0x990 [ 41.156682] ? handle_mm_fault+0x410/0x8d0 [ 41.160898] ? check_same_owner+0x320/0x320 [ 41.165186] ? up_read+0x1a/0x40 [ 41.168519] ? __do_page_fault+0x3d6/0xd60 [ 41.172724] ? tun_chr_compat_ioctl+0x30/0x30 [ 41.177188] tun_chr_ioctl+0x2a/0x40 [ 41.180871] ? tun_chr_ioctl+0x2a/0x40 [ 41.184730] do_vfs_ioctl+0x1b1/0x1520 [ 41.188590] ? ioctl_preallocate+0x2b0/0x2b0 [ 41.192970] ? selinux_capable+0x40/0x40 [ 41.196998] ? putname+0xf3/0x130 [ 41.200424] ? do_sys_open+0x320/0x6d0 [ 41.204289] ? security_file_ioctl+0x89/0xb0 [ 41.208669] SyS_ioctl+0x8f/0xc0 [ 41.212013] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 41.216734] RIP: 0033:0x443d89 [ 41.219891] RSP: 002b:00007ffc3cbbaf58 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 41.227566] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d89 [ 41.234803] RDX: 000000002087d000 RSI: 00000000400454ca RDI: 0000000000000004 [ 41.242041] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 41.249281] R10: 0000000000000000 R11: 0000000000000202 R12: b8d4f5e5cd2b9baf [ 41.256519] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 41.263772] [ 41.265369] Allocated by task 2976: [ 41.268967] save_stack_trace+0x16/0x20 [ 41.272911] save_stack+0x43/0xd0 [ 41.276331] kasan_kmalloc+0xad/0xe0 [ 41.280017] __kmalloc_node+0x47/0x70 [ 41.283784] kvmalloc_node+0x64/0xd0 [ 41.287466] alloc_netdev_mqs+0x16e/0xed0 [ 41.291584] __tun_chr_ioctl+0x12b2/0x3d20 [ 41.295782] tun_chr_ioctl+0x2a/0x40 [ 41.299464] do_vfs_ioctl+0x1b1/0x1520 [ 41.303320] SyS_ioctl+0x8f/0xc0 [ 41.306658] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 41.311375] [ 41.312969] Freed by task 2976: [ 41.316217] save_stack_trace+0x16/0x20 [ 41.320159] save_stack+0x43/0xd0 [ 41.323578] kasan_slab_free+0x71/0xc0 [ 41.327432] kfree+0xca/0x250 [ 41.330505] kvfree+0x36/0x60 [ 41.333579] free_netdev+0x2cf/0x360 [ 41.337257] __tun_chr_ioctl+0x2cea/0x3d20 [ 41.341459] tun_chr_ioctl+0x2a/0x40 [ 41.345140] do_vfs_ioctl+0x1b1/0x1520 [ 41.348991] SyS_ioctl+0x8f/0xc0 [ 41.352331] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 41.357052] [ 41.358648] The buggy address belongs to the object at ffff8801d21702c0 [ 41.358648] which belongs to the cache kmalloc-16384 of size 16384 [ 41.371615] The buggy address is located 13120 bytes inside of [ 41.371615] 16384-byte region [ffff8801d21702c0, ffff8801d21742c0) [ 41.383800] The buggy address belongs to the page: [ 41.388695] page:ffffea0007485c00 count:1 mapcount:0 mapping:ffff8801d21702c0 index:0x0 compound_mapcount: 0 [ 41.398629] flags: 0x200000000008100(slab|head) [ 41.403265] raw: 0200000000008100 ffff8801d21702c0 0000000000000000 0000000100000001 [ 41.411111] raw: ffffea0007014820 ffffea00073e6820 ffff8801dac02200 0000000000000000 [ 41.418954] page dumped because: kasan: bad access detected [ 41.424627] [ 41.426222] Memory state around the buggy address: [ 41.431116] ffff8801d2173500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.438448] ffff8801d2173580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.445788] >ffff8801d2173600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.453110] ^ [ 41.456439] ffff8801d2173680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.463762] ffff8801d2173700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.471085] ================================================================== [ 41.478408] Disabling lock debugging due to kernel taint [ 41.483820] Kernel panic - not syncing: panic_on_warn set ... [ 41.483820] [ 41.491148] CPU: 1 PID: 2976 Comm: syzkaller615990 Tainted: G B 4.14.0-rc5+ #137 [ 41.499773] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.509092] Call Trace: [ 41.511652] dump_stack+0x194/0x257 [ 41.515246] ? arch_local_irq_restore+0x53/0x53 [ 41.519878] ? kasan_end_report+0x32/0x50 [ 41.523994] ? lock_downgrade+0x990/0x990 [ 41.528110] ? __internal_add_timer+0x1c0/0x2d0 [ 41.532743] panic+0x1e4/0x417 [ 41.535907] ? __warn+0x1d9/0x1d9 [ 41.539331] ? __internal_add_timer+0x275/0x2d0 [ 41.543964] kasan_end_report+0x50/0x50 [ 41.547904] kasan_report+0x144/0x340 [ 41.551672] __asan_report_store8_noabort+0x17/0x20 [ 41.556653] __internal_add_timer+0x275/0x2d0 [ 41.561115] ? calc_wheel_index+0x200/0x200 [ 41.565405] mod_timer+0x622/0x15b0 [ 41.569004] ? mod_timer_pending+0x14e0/0x14e0 [ 41.573552] ? __lock_is_held+0xb6/0x140 [ 41.577584] ? __lock_is_held+0xb6/0x140 [ 41.581613] ? __lockdep_init_map+0xe4/0x650 [ 41.585988] ? lockdep_init_map+0x9/0x10 [ 41.590011] ? init_timer_key+0x126/0x3b0 [ 41.594125] ? try_to_del_timer_sync+0x120/0x120 [ 41.598847] ? round_jiffies_up+0xce/0x100 [ 41.603044] ? __round_jiffies_up_relative+0x150/0x150 [ 41.608288] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 41.613185] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 41.618691] __tun_chr_ioctl+0x1b17/0x3d20 [ 41.622893] ? tun_chr_read_iter+0x1e0/0x1e0 [ 41.627265] ? find_held_lock+0x35/0x1d0 [ 41.631296] ? __do_page_fault+0x64c/0xd60 [ 41.635497] ? lock_downgrade+0x990/0x990 [ 41.639615] ? handle_mm_fault+0x410/0x8d0 [ 41.643822] ? check_same_owner+0x320/0x320 [ 41.648106] ? up_read+0x1a/0x40 [ 41.651437] ? __do_page_fault+0x3d6/0xd60 [ 41.655639] ? tun_chr_compat_ioctl+0x30/0x30 [ 41.660098] tun_chr_ioctl+0x2a/0x40 [ 41.663778] ? tun_chr_ioctl+0x2a/0x40 [ 41.667631] do_vfs_ioctl+0x1b1/0x1520 [ 41.671490] ? ioctl_preallocate+0x2b0/0x2b0 [ 41.675867] ? selinux_capable+0x40/0x40 [ 41.679893] ? putname+0xf3/0x130 [ 41.683314] ? do_sys_open+0x320/0x6d0 [ 41.687169] ? security_file_ioctl+0x89/0xb0 [ 41.691543] SyS_ioctl+0x8f/0xc0 [ 41.694880] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 41.699601] RIP: 0033:0x443d89 [ 41.702755] RSP: 002b:00007ffc3cbbaf58 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 41.710427] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443d89 [ 41.717663] RDX: 000000002087d000 RSI: 00000000400454ca RDI: 0000000000000004 [ 41.724896] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 41.732131] R10: 0000000000000000 R11: 0000000000000202 R12: b8d4f5e5cd2b9baf [ 41.739371] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000