[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.988522] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.664351] random: sshd: uninitialized urandom read (32 bytes read) [ 25.020980] random: sshd: uninitialized urandom read (32 bytes read) [ 25.819810] random: sshd: uninitialized urandom read (32 bytes read) [ 108.247183] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.31' (ECDSA) to the list of known hosts. [ 113.732426] random: sshd: uninitialized urandom read (32 bytes read) net.ipv6.conf.syz_tun.accept_dad = 0 net.ipv6.conf.syz_tun.router_solicitations = 0 [ 113.833485] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 118.869389] ================================================================== [ 118.876976] BUG: KASAN: use-after-free in __dev_map_entry_free+0x2a8/0x300 [ 118.883994] Read of size 8 at addr ffff8801b8da38c8 by task ksoftirqd/1/18 [ 118.891000] [ 118.892630] CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.17.0+ #39 [ 118.899118] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 118.908537] Call Trace: [ 118.911140] dump_stack+0x1b9/0x294 [ 118.914774] ? dump_stack_print_info.cold.2+0x52/0x52 executing program executing program executing program executing program executing program executing program [ 118.919970] ? printk+0x9e/0xba [ 118.923266] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 118.928032] ? kasan_check_write+0x14/0x20 [ 118.932274] print_address_description+0x6c/0x20b [ 118.937121] ? __dev_map_entry_free+0x2a8/0x300 [ 118.941795] kasan_report.cold.7+0x242/0x2fe [ 118.946212] __asan_report_load8_noabort+0x14/0x20 [ 118.951143] __dev_map_entry_free+0x2a8/0x300 [ 118.955663] ? dev_map_delete_elem+0x100/0x100 [ 118.960249] rcu_process_callbacks+0xe9d/0x1760 [ 118.964927] ? call_rcu_sched+0x20/0x20 executing program executing program executing program executing program executing program executing program [ 118.968910] ? lock_downgrade+0x8e0/0x8e0 [ 118.973060] ? finish_task_switch+0x182/0x840 [ 118.977576] ? kasan_check_read+0x11/0x20 [ 118.981729] ? do_raw_spin_unlock+0x9e/0x2e0 [ 118.986140] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 118.990723] ? compat_start_thread+0x80/0x80 [ 118.995144] ? _raw_spin_unlock_irq+0x27/0x70 [ 118.999655] ? kasan_check_write+0x14/0x20 [ 119.003900] ? finish_task_switch+0x28b/0x840 [ 119.008406] ? kasan_check_read+0x11/0x20 [ 119.012567] ? rcu_is_watching+0x85/0x140 [ 119.016725] ? rcu_pm_notify+0xc0/0xc0 executing program executing program executing program executing program executing program [ 119.020625] __do_softirq+0x2e0/0xaf5 [ 119.024440] ? __irqentry_text_end+0x1f98a8/0x1f98a8 [ 119.029561] ? find_held_lock+0x36/0x1c0 [ 119.033635] ? schedule+0xef/0x430 [ 119.037351] ? schedule+0xef/0x430 [ 119.040890] ? find_held_lock+0x36/0x1c0 [ 119.044964] ? check_same_owner+0x320/0x320 [ 119.049284] ? schedule+0xef/0x430 [ 119.052835] ? takeover_tasklets+0xa50/0xa50 [ 119.057243] ? takeover_tasklets+0xa50/0xa50 [ 119.061652] run_ksoftirqd+0x86/0x100 [ 119.065455] smpboot_thread_fn+0x417/0x870 executing program executing program executing program executing program executing program executing program [ 119.069695] ? sort_range+0x30/0x30 [ 119.073328] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 119.078353] ? trace_hardirqs_on+0xd/0x10 [ 119.082516] kthread+0x345/0x410 [ 119.086069] ? sort_range+0x30/0x30 [ 119.089699] ? kthread_bind+0x40/0x40 [ 119.093504] ret_from_fork+0x3a/0x50 [ 119.097227] [ 119.098850] Allocated by task 6675: [ 119.102486] save_stack+0x43/0xd0 [ 119.105946] kasan_kmalloc+0xc4/0xe0 [ 119.109658] kmem_cache_alloc_trace+0x152/0x780 [ 119.114327] dev_map_alloc+0x208/0x7f0 executing program executing program executing program executing program executing program executing program [ 119.118213] map_create+0x393/0x1010 [ 119.121922] __x64_sys_bpf+0x303/0x510 [ 119.125808] do_syscall_64+0x1b1/0x800 [ 119.129699] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 119.134884] [ 119.136511] Freed by task 26: [ 119.139626] save_stack+0x43/0xd0 [ 119.143085] __kasan_slab_free+0x11a/0x170 [ 119.147319] kasan_slab_free+0xe/0x10 [ 119.151119] kfree+0xd9/0x260 [ 119.154223] dev_map_free+0x4fa/0x670 [ 119.158029] bpf_map_free_deferred+0xba/0xf0 [ 119.162439] process_one_work+0xc64/0x1b70 [ 119.166684] worker_thread+0x181/0x13a0 executing program executing program executing program executing program executing program executing program [ 119.170656] kthread+0x345/0x410 [ 119.174026] ret_from_fork+0x3a/0x50 [ 119.177731] [ 119.179359] The buggy address belongs to the object at ffff8801b8da37c0 [ 119.179359] which belongs to the cache kmalloc-512 of size 512 [ 119.192016] The buggy address is located 264 bytes inside of [ 119.192016] 512-byte region [ffff8801b8da37c0, ffff8801b8da39c0) [ 119.203887] The buggy address belongs to the page: [ 119.208909] page:ffffea0006e368c0 count:1 mapcount:0 mapping:ffff8801da800940 index:0xffff8801b8da3540 executing program executing program executing program executing program executing program [ 119.218359] flags: 0x2fffc0000000100(slab) [ 119.222597] raw: 02fffc0000000100 ffffea0007217b88 ffffea0006e30cc8 ffff8801da800940 [ 119.230487] raw: ffff8801b8da3540 ffff8801b8da3040 0000000100000004 0000000000000000 [ 119.238368] page dumped because: kasan: bad access detected [ 119.244078] [ 119.245701] Memory state around the buggy address: [ 119.250630] ffff8801b8da3780: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 119.257982] ffff8801b8da3800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program executing program executing program executing program executing program executing program executing program [ 119.265334] >ffff8801b8da3880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 119.272685] ^ [ 119.278395] ffff8801b8da3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 119.285756] ffff8801b8da3980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 119.293116] ================================================================== [ 119.300467] Disabling lock debugging due to kernel taint [ 119.305967] Kernel panic - not syncing: panic_on_warn set ... [ 119.305967] [ 119.313334] CPU: 1 PID: 18 Comm: ksoftirqd/1 Tainted: G B 4.17.0+ #39 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 119.321209] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 119.330547] Call Trace: [ 119.333144] dump_stack+0x1b9/0x294 [ 119.336778] ? dump_stack_print_info.cold.2+0x52/0x52 [ 119.341971] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 119.346728] ? __dev_map_entry_free+0x240/0x300 [ 119.351406] panic+0x22f/0x4de [ 119.354604] ? add_taint.cold.5+0x16/0x16 [ 119.358760] ? do_raw_spin_unlock+0x9e/0x2e0 [ 119.363174] ? do_raw_spin_unlock+0x9e/0x2e0 [ 119.367586] ? __dev_map_entry_free+0x2a8/0x300 executing program executing program executing program executing program executing program executing program executing program executing program [ 119.372263] kasan_end_report+0x47/0x4f [ 119.376239] kasan_report.cold.7+0x76/0x2fe [ 119.380559] __asan_report_load8_noabort+0x14/0x20 [ 119.385489] __dev_map_entry_free+0x2a8/0x300 [ 119.389986] ? dev_map_delete_elem+0x100/0x100 [ 119.394572] rcu_process_callbacks+0xe9d/0x1760 [ 119.399245] ? call_rcu_sched+0x20/0x20 [ 119.403212] ? lock_downgrade+0x8e0/0x8e0 [ 119.407349] ? finish_task_switch+0x182/0x840 [ 119.411844] ? kasan_check_read+0x11/0x20 [ 119.415999] ? do_raw_spin_unlock+0x9e/0x2e0 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 119.420410] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 119.424992] ? compat_start_thread+0x80/0x80 [ 119.429401] ? _raw_spin_unlock_irq+0x27/0x70 [ 119.433901] ? kasan_check_write+0x14/0x20 [ 119.438137] ? finish_task_switch+0x28b/0x840 [ 119.442632] ? kasan_check_read+0x11/0x20 [ 119.446784] ? rcu_is_watching+0x85/0x140 [ 119.450930] ? rcu_pm_notify+0xc0/0xc0 [ 119.454820] __do_softirq+0x2e0/0xaf5 [ 119.458621] ? __irqentry_text_end+0x1f98a8/0x1f98a8 [ 119.463722] ? find_held_lock+0x36/0x1c0 [ 119.467782] ? schedule+0xef/0x430 executing program executing program executing program executing program executing program executing program executing program executing program [ 119.471323] ? schedule+0xef/0x430 [ 119.474865] ? find_held_lock+0x36/0x1c0 [ 119.478933] ? check_same_owner+0x320/0x320 [ 119.483255] ? schedule+0xef/0x430 [ 119.486797] ? takeover_tasklets+0xa50/0xa50 [ 119.491207] ? takeover_tasklets+0xa50/0xa50 [ 119.495617] run_ksoftirqd+0x86/0x100 [ 119.499422] smpboot_thread_fn+0x417/0x870 [ 119.503659] ? sort_range+0x30/0x30 [ 119.507284] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 119.512302] ? trace_hardirqs_on+0xd/0x10 [ 119.516450] kthread+0x345/0x410 executing program [ 119.519816] ? sort_range+0x30/0x30 [ 119.523438] ? kthread_bind+0x40/0x40 [ 119.527241] ret_from_fork+0x3a/0x50 [ 119.531404] Dumping ftrace buffer: [ 119.534926] (ftrace buffer empty) [ 119.538609] Kernel Offset: disabled [ 119.542212] Rebooting in 86400 seconds..