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-386-4,10.128.15.228' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 33.322689] ================================================================== [ 33.323842] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 33.324767] Write of size 8 at addr ffff8801d21b3500 by task syzkaller470781/2989 [ 33.325778] [ 33.326011] CPU: 0 PID: 2989 Comm: syzkaller470781 Not tainted 4.14.0-rc5+ #52 [ 33.326985] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.328247] Call Trace: [ 33.328604] dump_stack+0x194/0x257 [ 33.329095] ? arch_local_irq_restore+0x53/0x53 [ 33.329718] ? show_regs_print_info+0x65/0x65 [ 33.330335] ? __kernel_text_address+0xd/0x40 [ 33.330966] ? __internal_add_timer+0x275/0x2d0 [ 33.331605] print_address_description+0x73/0x250 [ 33.332276] ? __internal_add_timer+0x275/0x2d0 [ 33.332897] kasan_report+0x25b/0x340 [ 33.333412] __asan_report_store8_noabort+0x17/0x20 [ 33.334079] __internal_add_timer+0x275/0x2d0 [ 33.334802] ? calc_wheel_index+0x200/0x200 [ 33.335390] mod_timer+0x622/0x15b0 [ 33.335886] ? mod_timer_pending+0x14e0/0x14e0 [ 33.336496] ? __lock_is_held+0xb6/0x140 [ 33.337053] ? __lock_is_held+0xb6/0x140 [ 33.337604] ? __lockdep_init_map+0xe4/0x650 [ 33.338194] ? lockdep_init_map+0x9/0x10 [ 33.338735] ? init_timer_key+0x126/0x3b0 [ 33.339305] ? try_to_del_timer_sync+0x120/0x120 [ 33.339940] ? round_jiffies_up+0xce/0x100 [ 33.340505] ? __round_jiffies_up_relative+0x150/0x150 [ 33.341206] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.341864] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 33.342655] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.345830] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.350206] ? find_held_lock+0x35/0x1d0 [ 33.354241] ? __might_sleep+0x95/0x190 [ 33.358184] ? handle_mm_fault+0x248/0x8d0 [ 33.362399] ? selinux_file_ioctl+0x444/0x690 [ 33.366863] ? __fget_light+0x297/0x380 [ 33.370809] ? selinux_capable+0x40/0x40 [ 33.374847] ? handle_mm_fault+0x410/0x8d0 [ 33.379056] tun_chr_compat_ioctl+0x29/0x30 [ 33.383349] ? tun_chr_compat_ioctl+0x29/0x30 [ 33.387814] compat_SyS_ioctl+0x1d7/0x3290 [ 33.392015] ? up_read+0x1a/0x40 [ 33.395350] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 33.399728] ? do_ioctl+0x60/0x60 [ 33.403150] ? do_fast_syscall_32+0x158/0xf05 [ 33.407866] ? do_ioctl+0x60/0x60 [ 33.411294] do_fast_syscall_32+0x3f2/0xf05 [ 33.415592] ? do_int80_syscall_32+0x940/0x940 [ 33.420140] ? kasan_check_read+0x11/0x20 [ 33.424254] ? syscall_return_slowpath+0x510/0x510 [ 33.429150] ? SyS_rt_sigaction+0x94/0x1b0 [ 33.433352] ? SyS_sigprocmask+0x4b0/0x4b0 [ 33.437556] ? SyS_read+0x184/0x220 [ 33.441166] ? retint_user+0x18/0x20 [ 33.444860] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 33.449675] entry_SYSENTER_compat+0x51/0x60 [ 33.454047] RIP: 0023:0xf7efdc79 [ 33.457375] RSP: 002b:00000000ffb4618c EFLAGS: 00000203 ORIG_RAX: 0000000000000036 [ 33.465052] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000400454ca [ 33.472290] RDX: 000000002087ffd8 RSI: 000000000000003f RDI: 0000000000000006 [ 33.479524] RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000 [ 33.486796] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 33.494040] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 33.501304] [ 33.502901] Allocated by task 2989: [ 33.506497] save_stack_trace+0x16/0x20 [ 33.510437] save_stack+0x43/0xd0 [ 33.513854] kasan_kmalloc+0xad/0xe0 [ 33.517530] __kmalloc_node+0x47/0x70 [ 33.521298] kvmalloc_node+0x64/0xd0 [ 33.524980] alloc_netdev_mqs+0x16e/0xed0 [ 33.529092] __tun_chr_ioctl+0x12b2/0x3d20 [ 33.533289] tun_chr_compat_ioctl+0x29/0x30 [ 33.537574] compat_SyS_ioctl+0x1d7/0x3290 [ 33.541775] do_fast_syscall_32+0x3f2/0xf05 [ 33.546065] entry_SYSENTER_compat+0x51/0x60 [ 33.550435] [ 33.552027] Freed by task 2989: [ 33.555271] save_stack_trace+0x16/0x20 [ 33.559215] save_stack+0x43/0xd0 [ 33.562636] kasan_slab_free+0x71/0xc0 [ 33.566489] kfree+0xca/0x250 [ 33.569562] kvfree+0x36/0x60 [ 33.572636] free_netdev+0x2cf/0x360 [ 33.576318] __tun_chr_ioctl+0x2cea/0x3d20 [ 33.580521] tun_chr_compat_ioctl+0x29/0x30 [ 33.584816] compat_SyS_ioctl+0x1d7/0x3290 [ 33.589015] do_fast_syscall_32+0x3f2/0xf05 [ 33.593300] entry_SYSENTER_compat+0x51/0x60 [ 33.597670] [ 33.599266] The buggy address belongs to the object at ffff8801d21b01c0 [ 33.599266] which belongs to the cache kmalloc-16384 of size 16384 [ 33.612231] The buggy address is located 13120 bytes inside of [ 33.612231] 16384-byte region [ffff8801d21b01c0, ffff8801d21b41c0) [ 33.624413] The buggy address belongs to the page: [ 33.629311] page:ffffea0007486c00 count:1 mapcount:0 mapping:ffff8801d21b01c0 index:0x0 compound_mapcount: 0 [ 33.639244] flags: 0x200000000008100(slab|head) [ 33.643878] raw: 0200000000008100 ffff8801d21b01c0 0000000000000000 0000000100000001 [ 33.651723] raw: ffffea000765c620 ffffea0007460c20 ffff8801dac02200 0000000000000000 [ 33.659565] page dumped because: kasan: bad access detected [ 33.665239] [ 33.666831] Memory state around the buggy address: [ 33.671723] ffff8801d21b3400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.679048] ffff8801d21b3480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.686369] >ffff8801d21b3500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.693690] ^ [ 33.697018] ffff8801d21b3580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.704343] ffff8801d21b3600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.711664] ================================================================== [ 33.718986] Disabling lock debugging due to kernel taint [ 33.724399] Kernel panic - not syncing: panic_on_warn set ... [ 33.724399] [ 33.731723] CPU: 0 PID: 2989 Comm: syzkaller470781 Tainted: G B 4.14.0-rc5+ #52 [ 33.740258] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.749574] Call Trace: [ 33.752130] dump_stack+0x194/0x257 [ 33.755722] ? arch_local_irq_restore+0x53/0x53 [ 33.760361] ? kasan_end_report+0x32/0x50 [ 33.764478] ? lock_downgrade+0x990/0x990 [ 33.768591] ? __internal_add_timer+0x1f0/0x2d0 [ 33.773224] panic+0x1e4/0x417 [ 33.776380] ? __warn+0x1d9/0x1d9 [ 33.779804] ? __internal_add_timer+0x275/0x2d0 [ 33.784434] kasan_end_report+0x50/0x50 [ 33.788371] kasan_report+0x144/0x340 [ 33.792140] __asan_report_store8_noabort+0x17/0x20 [ 33.797120] __internal_add_timer+0x275/0x2d0 [ 33.801581] ? calc_wheel_index+0x200/0x200 [ 33.805872] mod_timer+0x622/0x15b0 [ 33.809466] ? mod_timer_pending+0x14e0/0x14e0 [ 33.814011] ? __lock_is_held+0xb6/0x140 [ 33.818042] ? __lock_is_held+0xb6/0x140 [ 33.822070] ? __lockdep_init_map+0xe4/0x650 [ 33.826446] ? lockdep_init_map+0x9/0x10 [ 33.830475] ? init_timer_key+0x126/0x3b0 [ 33.834587] ? try_to_del_timer_sync+0x120/0x120 [ 33.839309] ? round_jiffies_up+0xce/0x100 [ 33.843519] ? __round_jiffies_up_relative+0x150/0x150 [ 33.848760] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.853656] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 33.859160] __tun_chr_ioctl+0x1b17/0x3d20 [ 33.863366] ? tun_chr_read_iter+0x1e0/0x1e0 [ 33.867740] ? find_held_lock+0x35/0x1d0 [ 33.871771] ? __might_sleep+0x95/0x190 [ 33.875708] ? handle_mm_fault+0x248/0x8d0 [ 33.879909] ? selinux_file_ioctl+0x444/0x690 [ 33.884367] ? __fget_light+0x297/0x380 [ 33.888306] ? selinux_capable+0x40/0x40 [ 33.892337] ? handle_mm_fault+0x410/0x8d0 [ 33.896538] tun_chr_compat_ioctl+0x29/0x30 [ 33.900821] ? tun_chr_compat_ioctl+0x29/0x30 [ 33.905283] compat_SyS_ioctl+0x1d7/0x3290 [ 33.909487] ? up_read+0x1a/0x40 [ 33.912819] ? __tun_chr_ioctl+0x3d20/0x3d20 [ 33.917190] ? do_ioctl+0x60/0x60 [ 33.920608] ? do_fast_syscall_32+0x158/0xf05 [ 33.925067] ? do_ioctl+0x60/0x60 [ 33.928483] do_fast_syscall_32+0x3f2/0xf05 [ 33.932771] ? do_int80_syscall_32+0x940/0x940 [ 33.937319] ? kasan_check_read+0x11/0x20 [ 33.941434] ? syscall_return_slowpath+0x510/0x510 [ 33.946327] ? SyS_rt_sigaction+0x94/0x1b0 [ 33.950526] ? SyS_sigprocmask+0x4b0/0x4b0 [ 33.954726] ? SyS_read+0x184/0x220 [ 33.958317] ? retint_user+0x18/0x20 [ 33.961995] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 33.966805] entry_SYSENTER_compat+0x51/0x60 [ 33.971174] RIP: 0023:0xf7efdc79 [ 33.974502] RSP: 002b:00000000ffb4618c EFLAGS: 00000203 ORIG_RAX: 0000000000000036 [ 33.982171] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000400454ca [ 33.989406] RDX: 000000002087ffd8 RSI: 000000000000003f RDI: 0000000000000006 [ 33.996649] RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000 [ 34.003887] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 34.011122] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 34.018735] Dumping ftrace buffer: [ 34.022243] (ftrace buffer empty) [ 34.025919] Kernel Offset: disabled [ 34.029510] Rebooting in 86400 seconds..