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-386-2,10.128.0.43' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 41.624471] ================================================================== [ 41.625605] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 41.626548] Write of size 8 at addr ffff8801d27b3600 by task syzkaller319675/2997 [ 41.627543] [ 41.627776] CPU: 1 PID: 2997 Comm: syzkaller319675 Not tainted 4.14.0-rc5+ #52 [ 41.628740] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.629961] Call Trace: [ 41.630323] dump_stack+0x194/0x257 [ 41.630816] ? arch_local_irq_restore+0x53/0x53 [ 41.631441] ? show_regs_print_info+0x65/0x65 [ 41.632061] ? __kernel_text_address+0xd/0x40 [ 41.632661] ? __internal_add_timer+0x275/0x2d0 [ 41.633286] print_address_description+0x73/0x250 [ 41.633933] ? __internal_add_timer+0x275/0x2d0 [ 41.634557] kasan_report+0x25b/0x340 [ 41.635090] __asan_report_store8_noabort+0x17/0x20 [ 41.635755] __internal_add_timer+0x275/0x2d0 [ 41.636358] ? calc_wheel_index+0x200/0x200 [ 41.636946] mod_timer+0x622/0x15b0 [ 41.637443] ? mod_timer_pending+0x14e0/0x14e0 [ 41.638069] ? __lock_is_held+0xb6/0x140 [ 41.638629] ? __lock_is_held+0xb6/0x140 [ 41.639182] ? __lockdep_init_map+0xe4/0x650 [ 41.639776] ? lockdep_init_map+0x9/0x10 [ 41.640321] ? init_timer_key+0x126/0x3b0 [ 41.640880] ? try_to_del_timer_sync+0x120/0x120 [ 41.641544] ? round_jiffies_up+0xce/0x100 [ 41.642130] ? __round_jiffies_up_relative+0x150/0x150 [ 41.642831] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 41.643488] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 41.644230] __tun_chr_ioctl+0x1b17/0x3d20 [ 41.645822] ? tun_chr_read_iter+0x1e0/0x1e0 [ 41.650197] ? find_held_lock+0x35/0x1d0 [ 41.654232] ? __might_sleep+0x95/0x190 [ 41.658184] ? handle_mm_fault+0x248/0x8d0 [ 41.662396] ? selinux_file_ioctl+0x444/0x690 [ 41.666859] ? __fget_light+0x297/0x380 [ 41.670804] ? selinux_capable+0x40/0x40 [ 41.674845] ? handle_mm_fault+0x410/0x8d0 [ 41.679054] tun_chr_compat_ioctl+0x29/0x30 [ 41.683342] ? tun_chr_compat_ioctl+0x29/0x30 [ 41.687811] compat_SyS_ioctl+0x1d7/0x3290 [ 41.692013] ? up_read+0x1a/0x40 [ 41.695349] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 41.699729] ? do_ioctl+0x60/0x60 [ 41.703155] ? do_fast_syscall_32+0x158/0xf05 [ 41.707624] ? do_ioctl+0x60/0x60 [ 41.711047] do_fast_syscall_32+0x3f2/0xf05 [ 41.715341] ? do_int80_syscall_32+0x940/0x940 [ 41.719891] ? kasan_check_read+0x11/0x20 [ 41.724007] ? syscall_return_slowpath+0x510/0x510 [ 41.728904] ? SyS_rt_sigaction+0x94/0x1b0 [ 41.733105] ? SyS_sigprocmask+0x4b0/0x4b0 [ 41.737307] ? SyS_read+0x184/0x220 [ 41.740902] ? retint_user+0x18/0x20 [ 41.744590] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 41.749407] entry_SYSENTER_compat+0x51/0x60 [ 41.753783] RIP: 0023:0xf7fb1c79 [ 41.757113] RSP: 002b:00000000ffdfb76c EFLAGS: 00000282 ORIG_RAX: 0000000000000036 [ 41.764788] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000400454ca [ 41.772027] RDX: 00000000209fa000 RSI: 00000000080ef00c RDI: 000000000000003f [ 41.779267] RBP: 0000000000001000 R08: 0000000000000000 R09: 0000000000000000 [ 41.786506] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 41.793744] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 41.801000] [ 41.802599] Allocated by task 2997: [ 41.806196] save_stack_trace+0x16/0x20 [ 41.810135] save_stack+0x43/0xd0 [ 41.813553] kasan_kmalloc+0xad/0xe0 [ 41.817234] __kmalloc_node+0x47/0x70 [ 41.821002] kvmalloc_node+0x64/0xd0 [ 41.824683] alloc_netdev_mqs+0x16e/0xed0 [ 41.828796] __tun_chr_ioctl+0x12b2/0x3d20 [ 41.833000] tun_chr_compat_ioctl+0x29/0x30 [ 41.837288] compat_SyS_ioctl+0x1d7/0x3290 [ 41.841490] do_fast_syscall_32+0x3f2/0xf05 [ 41.845781] entry_SYSENTER_compat+0x51/0x60 [ 41.850153] [ 41.851745] Freed by task 2997: [ 41.854994] save_stack_trace+0x16/0x20 [ 41.858935] save_stack+0x43/0xd0 [ 41.862353] kasan_slab_free+0x71/0xc0 [ 41.866206] kfree+0xca/0x250 [ 41.869280] kvfree+0x36/0x60 [ 41.872353] free_netdev+0x2cf/0x360 [ 41.876034] __tun_chr_ioctl+0x2cea/0x3d20 [ 41.880232] tun_chr_compat_ioctl+0x29/0x30 [ 41.884519] compat_SyS_ioctl+0x1d7/0x3290 [ 41.888721] do_fast_syscall_32+0x3f2/0xf05 [ 41.893007] entry_SYSENTER_compat+0x51/0x60 [ 41.897376] [ 41.898972] The buggy address belongs to the object at ffff8801d27b02c0 [ 41.898972] which belongs to the cache kmalloc-16384 of size 16384 [ 41.911940] The buggy address is located 13120 bytes inside of [ 41.911940] 16384-byte region [ffff8801d27b02c0, ffff8801d27b42c0) [ 41.924125] The buggy address belongs to the page: [ 41.929018] page:ffffea000749ec00 count:1 mapcount:0 mapping:ffff8801d27b02c0 index:0x0 compound_mapcount: 0 [ 41.938952] flags: 0x200000000008100(slab|head) [ 41.943587] raw: 0200000000008100 ffff8801d27b02c0 0000000000000000 0000000100000001 [ 41.951431] raw: ffffea0007659020 ffffea00074cc220 ffff8801dac02200 0000000000000000 [ 41.959276] page dumped because: kasan: bad access detected [ 41.964950] [ 41.966543] Memory state around the buggy address: [ 41.971435] ffff8801d27b3500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.978761] ffff8801d27b3580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.986083] >ffff8801d27b3600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.993404] ^ [ 41.996734] ffff8801d27b3680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.004058] ffff8801d27b3700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.011382] ================================================================== [ 42.018707] Disabling lock debugging due to kernel taint [ 42.024120] Kernel panic - not syncing: panic_on_warn set ... [ 42.024120] [ 42.031446] CPU: 1 PID: 2997 Comm: syzkaller319675 Tainted: G B 4.14.0-rc5+ #52 [ 42.039981] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.049297] Call Trace: [ 42.051852] dump_stack+0x194/0x257 [ 42.055444] ? arch_local_irq_restore+0x53/0x53 [ 42.060079] ? kasan_end_report+0x32/0x50 [ 42.064194] ? lock_downgrade+0x990/0x990 [ 42.068310] ? __internal_add_timer+0x1f0/0x2d0 [ 42.072945] panic+0x1e4/0x417 [ 42.076101] ? __warn+0x1d9/0x1d9 [ 42.079522] ? __internal_add_timer+0x275/0x2d0 [ 42.084152] kasan_end_report+0x50/0x50 [ 42.088091] kasan_report+0x144/0x340 [ 42.091858] __asan_report_store8_noabort+0x17/0x20 [ 42.096838] __internal_add_timer+0x275/0x2d0 [ 42.101297] ? calc_wheel_index+0x200/0x200 [ 42.105587] mod_timer+0x622/0x15b0 [ 42.109188] ? mod_timer_pending+0x14e0/0x14e0 [ 42.113733] ? __lock_is_held+0xb6/0x140 [ 42.117768] ? __lock_is_held+0xb6/0x140 [ 42.121795] ? __lockdep_init_map+0xe4/0x650 [ 42.126178] ? lockdep_init_map+0x9/0x10 [ 42.130206] ? init_timer_key+0x126/0x3b0 [ 42.134317] ? try_to_del_timer_sync+0x120/0x120 [ 42.139036] ? round_jiffies_up+0xce/0x100 [ 42.143235] ? __round_jiffies_up_relative+0x150/0x150 [ 42.148477] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 42.153372] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 42.158879] __tun_chr_ioctl+0x1b17/0x3d20 [ 42.163082] ? tun_chr_read_iter+0x1e0/0x1e0 [ 42.167455] ? find_held_lock+0x35/0x1d0 [ 42.171486] ? __might_sleep+0x95/0x190 [ 42.175424] ? handle_mm_fault+0x248/0x8d0 [ 42.179626] ? selinux_file_ioctl+0x444/0x690 [ 42.184087] ? __fget_light+0x297/0x380 [ 42.188029] ? selinux_capable+0x40/0x40 [ 42.192059] ? handle_mm_fault+0x410/0x8d0 [ 42.196260] tun_chr_compat_ioctl+0x29/0x30 [ 42.200544] ? tun_chr_compat_ioctl+0x29/0x30 [ 42.205006] compat_SyS_ioctl+0x1d7/0x3290 [ 42.209204] ? up_read+0x1a/0x40 [ 42.212535] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 42.216910] ? do_ioctl+0x60/0x60 [ 42.220332] ? do_fast_syscall_32+0x158/0xf05 [ 42.224791] ? do_ioctl+0x60/0x60 [ 42.228207] do_fast_syscall_32+0x3f2/0xf05 [ 42.232495] ? do_int80_syscall_32+0x940/0x940 [ 42.237042] ? kasan_check_read+0x11/0x20 [ 42.241155] ? syscall_return_slowpath+0x510/0x510 [ 42.246050] ? SyS_rt_sigaction+0x94/0x1b0 [ 42.250246] ? SyS_sigprocmask+0x4b0/0x4b0 [ 42.254446] ? SyS_read+0x184/0x220 [ 42.258040] ? retint_user+0x18/0x20 [ 42.261720] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.266543] entry_SYSENTER_compat+0x51/0x60 [ 42.270916] RIP: 0023:0xf7fb1c79 [ 42.274243] RSP: 002b:00000000ffdfb76c EFLAGS: 00000282 ORIG_RAX: 0000000000000036 [ 42.281913] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000400454ca [ 42.289148] RDX: 00000000209fa000 RSI: 00000000080ef00c RDI: 000000000000003f [ 42.296381] RBP: 0000000000001000 R08: 0000000000000000 R09: 0000000000000000 [ 42.303615] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 42.310848] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 42.318129] Dumping ftrace buffer: [ 42.321637] (ftrace buffer empty) [ 42.325312] Kernel Offset: disabled [ 42.328905] Rebooting in 86400 seconds..