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-386-1,10.128.0.44' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 28.297167] ================================================================== [ 28.298297] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 28.299261] Write of size 8 at addr ffff8801d1dcb600 by task syzkaller056214/2983 [ 28.300312] [ 28.300558] CPU: 1 PID: 2983 Comm: syzkaller056214 Not tainted 4.14.0-rc5+ #51 [ 28.301523] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.302782] Call Trace: [ 28.303157] dump_stack+0x194/0x257 [ 28.303649] ? arch_local_irq_restore+0x53/0x53 [ 28.304272] ? show_regs_print_info+0x65/0x65 [ 28.304878] ? __kernel_text_address+0xd/0x40 [ 28.305480] ? __internal_add_timer+0x275/0x2d0 [ 28.306104] print_address_description+0x73/0x250 [ 28.306747] ? __internal_add_timer+0x275/0x2d0 [ 28.307406] kasan_report+0x25b/0x340 [ 28.307924] __asan_report_store8_noabort+0x17/0x20 [ 28.308589] __internal_add_timer+0x275/0x2d0 [ 28.309192] ? calc_wheel_index+0x200/0x200 [ 28.309783] mod_timer+0x622/0x15b0 [ 28.310282] ? mod_timer_pending+0x14e0/0x14e0 [ 28.310894] ? __lock_is_held+0xb6/0x140 [ 28.311451] ? __lock_is_held+0xb6/0x140 [ 28.312001] ? __lockdep_init_map+0xe4/0x650 [ 28.312592] ? lockdep_init_map+0x9/0x10 [ 28.313134] ? init_timer_key+0x126/0x3b0 [ 28.313692] ? try_to_del_timer_sync+0x120/0x120 [ 28.314328] ? round_jiffies_up+0xce/0x100 [ 28.314894] ? __round_jiffies_up_relative+0x150/0x150 [ 28.315616] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 28.316271] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 28.317015] __tun_chr_ioctl+0x1b17/0x3d20 [ 28.317594] ? tun_chr_read_iter+0x1e0/0x1e0 [ 28.321970] ? find_held_lock+0x35/0x1d0 [ 28.326006] ? __might_sleep+0x95/0x190 [ 28.329948] ? handle_mm_fault+0x248/0x8d0 [ 28.334158] ? selinux_file_ioctl+0x444/0x690 [ 28.338622] ? __fget_light+0x297/0x380 [ 28.342570] ? selinux_capable+0x40/0x40 [ 28.346609] ? handle_mm_fault+0x410/0x8d0 [ 28.350819] tun_chr_compat_ioctl+0x29/0x30 [ 28.355105] ? tun_chr_compat_ioctl+0x29/0x30 [ 28.359574] compat_SyS_ioctl+0x1d7/0x3290 [ 28.363774] ? up_read+0x1a/0x40 [ 28.367110] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 28.371490] ? do_ioctl+0x60/0x60 [ 28.374914] ? do_fast_syscall_32+0x158/0xf05 [ 28.379379] ? do_ioctl+0x60/0x60 [ 28.382801] do_fast_syscall_32+0x3f2/0xf05 [ 28.387095] ? do_int80_syscall_32+0x940/0x940 [ 28.391643] ? kasan_check_read+0x11/0x20 [ 28.395762] ? syscall_return_slowpath+0x510/0x510 [ 28.400659] ? SyS_rt_sigaction+0x94/0x1b0 [ 28.404863] ? SyS_sigprocmask+0x4b0/0x4b0 [ 28.409062] ? SyS_read+0x184/0x220 [ 28.412662] ? retint_user+0x18/0x20 [ 28.416351] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 28.421188] entry_SYSENTER_compat+0x51/0x60 [ 28.425581] RIP: 0023:0xf7f23c79 [ 28.428912] RSP: 002b:00000000ff8c882c EFLAGS: 00000207 ORIG_RAX: 0000000000000036 [ 28.436588] RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00000000400454ca [ 28.443829] RDX: 0000000020e4a000 RSI: 0000000000000037 RDI: 0000000000000005 [ 28.451066] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 28.458305] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 28.466759] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 28.474014] [ 28.475609] Allocated by task 2983: [ 28.479206] save_stack_trace+0x16/0x20 [ 28.484407] save_stack+0x43/0xd0 [ 28.487826] kasan_kmalloc+0xad/0xe0 [ 28.491506] __kmalloc_node+0x47/0x70 [ 28.495273] kvmalloc_node+0x64/0xd0 [ 28.498959] alloc_netdev_mqs+0x16e/0xed0 [ 28.503071] __tun_chr_ioctl+0x12b2/0x3d20 [ 28.507272] tun_chr_compat_ioctl+0x29/0x30 [ 28.511562] compat_SyS_ioctl+0x1d7/0x3290 [ 28.515763] do_fast_syscall_32+0x3f2/0xf05 [ 28.520051] entry_SYSENTER_compat+0x51/0x60 [ 28.524423] [ 28.526017] Freed by task 2983: [ 28.529261] save_stack_trace+0x16/0x20 [ 28.533199] save_stack+0x43/0xd0 [ 28.536615] kasan_slab_free+0x71/0xc0 [ 28.540467] kfree+0xca/0x250 [ 28.543543] kvfree+0x36/0x60 [ 28.546618] free_netdev+0x2cf/0x360 [ 28.550297] __tun_chr_ioctl+0x2cea/0x3d20 [ 28.554496] tun_chr_compat_ioctl+0x29/0x30 [ 28.558783] compat_SyS_ioctl+0x1d7/0x3290 [ 28.562983] do_fast_syscall_32+0x3f2/0xf05 [ 28.567269] entry_SYSENTER_compat+0x51/0x60 [ 28.571639] [ 28.573235] The buggy address belongs to the object at ffff8801d1dc82c0 [ 28.573235] which belongs to the cache kmalloc-16384 of size 16384 [ 28.586202] The buggy address is located 13120 bytes inside of [ 28.586202] 16384-byte region [ffff8801d1dc82c0, ffff8801d1dcc2c0) [ 28.598386] The buggy address belongs to the page: [ 28.603280] page:ffffea0007477200 count:1 mapcount:0 mapping:ffff8801d1dc82c0 index:0x0 compound_mapcount: 0 [ 28.613215] flags: 0x200000000008100(slab|head) [ 28.617851] raw: 0200000000008100 ffff8801d1dc82c0 0000000000000000 0000000100000001 [ 28.625699] raw: ffffea0007659620 ffffea0007474020 ffff8801dac02200 0000000000000000 [ 28.633543] page dumped because: kasan: bad access detected [ 28.639219] [ 28.640811] Memory state around the buggy address: [ 28.645707] ffff8801d1dcb500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.653030] ffff8801d1dcb580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.660361] >ffff8801d1dcb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.667685] ^ [ 28.671016] ffff8801d1dcb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.678338] ffff8801d1dcb700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.685659] ================================================================== [ 28.692981] Disabling lock debugging due to kernel taint [ 28.698394] Kernel panic - not syncing: panic_on_warn set ... [ 28.698394] [ 28.705718] CPU: 1 PID: 2983 Comm: syzkaller056214 Tainted: G B 4.14.0-rc5+ #51 [ 28.714254] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.723570] Call Trace: [ 28.726123] dump_stack+0x194/0x257 [ 28.729714] ? arch_local_irq_restore+0x53/0x53 [ 28.734345] ? kasan_end_report+0x32/0x50 [ 28.738460] ? lock_downgrade+0x990/0x990 [ 28.742575] ? __internal_add_timer+0x1f0/0x2d0 [ 28.747218] panic+0x1e4/0x417 [ 28.750374] ? __warn+0x1d9/0x1d9 [ 28.753796] ? __internal_add_timer+0x275/0x2d0 [ 28.758428] kasan_end_report+0x50/0x50 [ 28.762367] kasan_report+0x144/0x340 [ 28.766134] __asan_report_store8_noabort+0x17/0x20 [ 28.771112] __internal_add_timer+0x275/0x2d0 [ 28.775571] ? calc_wheel_index+0x200/0x200 [ 28.779862] mod_timer+0x622/0x15b0 [ 28.783458] ? mod_timer_pending+0x14e0/0x14e0 [ 28.788017] ? __lock_is_held+0xb6/0x140 [ 28.792070] ? __lock_is_held+0xb6/0x140 [ 28.796101] ? __lockdep_init_map+0xe4/0x650 [ 28.800479] ? lockdep_init_map+0x9/0x10 [ 28.804506] ? init_timer_key+0x126/0x3b0 [ 28.808620] ? try_to_del_timer_sync+0x120/0x120 [ 28.813343] ? round_jiffies_up+0xce/0x100 [ 28.817542] ? __round_jiffies_up_relative+0x150/0x150 [ 28.822784] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 28.827686] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 28.833190] __tun_chr_ioctl+0x1b17/0x3d20 [ 28.837394] ? tun_chr_read_iter+0x1e0/0x1e0 [ 28.841778] ? find_held_lock+0x35/0x1d0 [ 28.845808] ? __might_sleep+0x95/0x190 [ 28.849745] ? handle_mm_fault+0x248/0x8d0 [ 28.853946] ? selinux_file_ioctl+0x444/0x690 [ 28.858406] ? __fget_light+0x297/0x380 [ 28.862346] ? selinux_capable+0x40/0x40 [ 28.866377] ? handle_mm_fault+0x410/0x8d0 [ 28.870579] tun_chr_compat_ioctl+0x29/0x30 [ 28.874866] ? tun_chr_compat_ioctl+0x29/0x30 [ 28.879328] compat_SyS_ioctl+0x1d7/0x3290 [ 28.883539] ? up_read+0x1a/0x40 [ 28.886879] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 28.891253] ? do_ioctl+0x60/0x60 [ 28.894674] ? do_fast_syscall_32+0x158/0xf05 [ 28.899133] ? do_ioctl+0x60/0x60 [ 28.902554] do_fast_syscall_32+0x3f2/0xf05 [ 28.906845] ? do_int80_syscall_32+0x940/0x940 [ 28.911393] ? kasan_check_read+0x11/0x20 [ 28.915507] ? syscall_return_slowpath+0x510/0x510 [ 28.920402] ? SyS_rt_sigaction+0x94/0x1b0 [ 28.924603] ? SyS_sigprocmask+0x4b0/0x4b0 [ 28.928804] ? SyS_read+0x184/0x220 [ 28.932400] ? retint_user+0x18/0x20 [ 28.936080] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 28.940889] entry_SYSENTER_compat+0x51/0x60 [ 28.945260] RIP: 0023:0xf7f23c79 [ 28.948588] RSP: 002b:00000000ff8c882c EFLAGS: 00000207 ORIG_RAX: 0000000000000036 [ 28.956258] RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00000000400454ca [ 28.963499] RDX: 0000000020e4a000 RSI: 0000000000000037 RDI: 0000000000000005 [ 28.970735] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 28.977970] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 28.985208] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 28.992499] Dumping ftrace buffer: [ 28.996008] (ftrace buffer empty) [ 28.999694] Kernel Offset: disabled [ 29.003287] Rebooting in 86400 seconds..