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-6,10.128.15.233' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 33.330293] ================================================================== [ 33.331451] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 33.332373] Write of size 8 at addr ffff8801d2193500 by task syzkaller563996/2986 [ 33.333424] [ 33.333662] CPU: 1 PID: 2986 Comm: syzkaller563996 Not tainted 4.14.0-rc5+ #142 [ 33.334664] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.335912] Call Trace: [ 33.336269] dump_stack+0x194/0x257 [ 33.336762] ? arch_local_irq_restore+0x53/0x53 [ 33.337383] ? show_regs_print_info+0x65/0x65 [ 33.337986] ? __kernel_text_address+0xd/0x40 [ 33.338608] ? __internal_add_timer+0x275/0x2d0 [ 33.339268] print_address_description+0x73/0x250 [ 33.339912] ? __internal_add_timer+0x275/0x2d0 [ 33.340547] kasan_report+0x25b/0x340 [ 33.341167] __asan_report_store8_noabort+0x17/0x20 [ 33.342002] __internal_add_timer+0x275/0x2d0 [ 33.342661] ? calc_wheel_index+0x200/0x200 [ 33.343293] mod_timer+0x622/0x15b0 [ 33.343823] ? mod_timer_pending+0x14e0/0x14e0 [ 33.344435] ? __lock_is_held+0xb6/0x140 [ 33.344993] ? __lock_is_held+0xb6/0x140 [ 33.345546] ? __lockdep_init_map+0xe4/0x650 [ 33.346138] ? lockdep_init_map+0x9/0x10 [ 33.346681] ? init_timer_key+0x126/0x3b0 [ 33.347280] ? try_to_del_timer_sync+0x120/0x120 [ 33.347938] ? round_jiffies_up+0xce/0x100 [ 33.348518] ? __round_jiffies_up_relative+0x150/0x150 [ 33.349221] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.350082] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 33.354048] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.358259] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.362634] ? find_held_lock+0x35/0x1d0 [ 33.366689] ? __do_page_fault+0x64c/0xd60 [ 33.370900] ? lock_downgrade+0x990/0x990 [ 33.375025] ? handle_mm_fault+0x410/0x8d0 [ 33.379241] ? check_same_owner+0x320/0x320 [ 33.383527] ? up_read+0x1a/0x40 [ 33.386863] ? __do_page_fault+0x3d6/0xd60 [ 33.391067] ? tun_chr_compat_ioctl+0x30/0x30 [ 33.395528] tun_chr_ioctl+0x2a/0x40 [ 33.399207] ? tun_chr_ioctl+0x2a/0x40 [ 33.403076] do_vfs_ioctl+0x1b1/0x1520 [ 33.406945] ? ioctl_preallocate+0x2b0/0x2b0 [ 33.411323] ? selinux_capable+0x40/0x40 [ 33.415355] ? putname+0xf3/0x130 [ 33.418795] ? do_sys_open+0x320/0x6d0 [ 33.422669] ? security_file_ioctl+0x89/0xb0 [ 33.427051] SyS_ioctl+0x8f/0xc0 [ 33.430394] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.435117] RIP: 0033:0x443da9 [ 33.438275] RSP: 002b:00007ffeea1b40c8 EFLAGS: 00000207 ORIG_RAX: 0000000000000010 [ 33.445961] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443da9 [ 33.453209] RDX: 0000000020927fd8 RSI: 00000000400454ca RDI: 0000000000000006 [ 33.460465] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 33.467702] R10: 0000000000000000 R11: 0000000000000207 R12: 0de5fe9a30d03188 [ 33.474939] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 33.482191] [ 33.483787] Allocated by task 2986: [ 33.487380] save_stack_trace+0x16/0x20 [ 33.491320] save_stack+0x43/0xd0 [ 33.494738] kasan_kmalloc+0xad/0xe0 [ 33.498417] __kmalloc_node+0x47/0x70 [ 33.502184] kvmalloc_node+0x64/0xd0 [ 33.505865] alloc_netdev_mqs+0x16e/0xed0 [ 33.509978] __tun_chr_ioctl+0x12b2/0x3d20 [ 33.514178] tun_chr_ioctl+0x2a/0x40 [ 33.517856] do_vfs_ioctl+0x1b1/0x1520 [ 33.521709] SyS_ioctl+0x8f/0xc0 [ 33.525039] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.529756] [ 33.531349] Freed by task 2986: [ 33.534595] save_stack_trace+0x16/0x20 [ 33.538535] save_stack+0x43/0xd0 [ 33.541952] kasan_slab_free+0x71/0xc0 [ 33.545808] kfree+0xca/0x250 [ 33.548878] kvfree+0x36/0x60 [ 33.551957] free_netdev+0x2cf/0x360 [ 33.555644] __tun_chr_ioctl+0x2cea/0x3d20 [ 33.559846] tun_chr_ioctl+0x2a/0x40 [ 33.563522] do_vfs_ioctl+0x1b1/0x1520 [ 33.567385] SyS_ioctl+0x8f/0xc0 [ 33.570739] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.575458] [ 33.577055] The buggy address belongs to the object at ffff8801d21901c0 [ 33.577055] which belongs to the cache kmalloc-16384 of size 16384 [ 33.590023] The buggy address is located 13120 bytes inside of [ 33.590023] 16384-byte region [ffff8801d21901c0, ffff8801d21941c0) [ 33.602210] The buggy address belongs to the page: [ 33.607105] page:ffffea0007486400 count:1 mapcount:0 mapping:ffff8801d21901c0 index:0x0 compound_mapcount: 0 [ 33.617038] flags: 0x200000000008100(slab|head) [ 33.621676] raw: 0200000000008100 ffff8801d21901c0 0000000000000000 0000000100000001 [ 33.629523] raw: ffffea000765ca20 ffffea000748b620 ffff8801dac02200 0000000000000000 [ 33.637368] page dumped because: kasan: bad access detected [ 33.643047] [ 33.644654] Memory state around the buggy address: [ 33.649557] ffff8801d2193400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.656883] ffff8801d2193480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.664207] >ffff8801d2193500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.671551] ^ [ 33.674884] ffff8801d2193580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.682209] ffff8801d2193600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.689531] ================================================================== [ 33.696853] Disabling lock debugging due to kernel taint [ 33.702267] Kernel panic - not syncing: panic_on_warn set ... [ 33.702267] [ 33.709595] CPU: 1 PID: 2986 Comm: syzkaller563996 Tainted: G B 4.14.0-rc5+ #142 [ 33.718218] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.727535] Call Trace: [ 33.730090] dump_stack+0x194/0x257 [ 33.733684] ? arch_local_irq_restore+0x53/0x53 [ 33.738317] ? kasan_end_report+0x32/0x50 [ 33.742430] ? lock_downgrade+0x990/0x990 [ 33.746545] ? __internal_add_timer+0x1f0/0x2d0 [ 33.751179] panic+0x1e4/0x417 [ 33.754336] ? __warn+0x1d9/0x1d9 [ 33.757760] ? __internal_add_timer+0x275/0x2d0 [ 33.762391] kasan_end_report+0x50/0x50 [ 33.766328] kasan_report+0x144/0x340 [ 33.770093] __asan_report_store8_noabort+0x17/0x20 [ 33.775074] __internal_add_timer+0x275/0x2d0 [ 33.779533] ? calc_wheel_index+0x200/0x200 [ 33.783823] mod_timer+0x622/0x15b0 [ 33.787421] ? mod_timer_pending+0x14e0/0x14e0 [ 33.791968] ? __lock_is_held+0xb6/0x140 [ 33.796003] ? __lock_is_held+0xb6/0x140 [ 33.800033] ? __lockdep_init_map+0xe4/0x650 [ 33.804408] ? lockdep_init_map+0x9/0x10 [ 33.808432] ? init_timer_key+0x126/0x3b0 [ 33.812545] ? try_to_del_timer_sync+0x120/0x120 [ 33.817265] ? round_jiffies_up+0xce/0x100 [ 33.821465] ? __round_jiffies_up_relative+0x150/0x150 [ 33.826708] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.831606] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 33.837112] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.841316] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.845690] ? find_held_lock+0x35/0x1d0 [ 33.849722] ? __do_page_fault+0x64c/0xd60 [ 33.853922] ? lock_downgrade+0x990/0x990 [ 33.858038] ? handle_mm_fault+0x410/0x8d0 [ 33.862244] ? check_same_owner+0x320/0x320 [ 33.866529] ? up_read+0x1a/0x40 [ 33.869860] ? __do_page_fault+0x3d6/0xd60 [ 33.874062] ? tun_chr_compat_ioctl+0x30/0x30 [ 33.878524] tun_chr_ioctl+0x2a/0x40 [ 33.882204] ? tun_chr_ioctl+0x2a/0x40 [ 33.886057] do_vfs_ioctl+0x1b1/0x1520 [ 33.889912] ? ioctl_preallocate+0x2b0/0x2b0 [ 33.894285] ? selinux_capable+0x40/0x40 [ 33.898311] ? putname+0xf3/0x130 [ 33.901731] ? do_sys_open+0x320/0x6d0 [ 33.905588] ? security_file_ioctl+0x89/0xb0 [ 33.909963] SyS_ioctl+0x8f/0xc0 [ 33.913315] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 33.918035] RIP: 0033:0x443da9 [ 33.921190] RSP: 002b:00007ffeea1b40c8 EFLAGS: 00000207 ORIG_RAX: 0000000000000010 [ 33.928861] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000443da9 [ 33.936094] RDX: 0000000020927fd8 RSI: 00000000400454ca RDI: 0000000000000006 [ 33.943328] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 33.950563] R10: 0000000000000000 R11: 0000000000000207 R12: 0de5fe9a30d03188 [ 33.957797] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 33.965079] Dumping ftrace buffer: [ 33.968584] (ftrace buffer empty) [ 33.972259] Kernel Offset: disabled [ 33.975852] Rebooting in 86400 seconds..