[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.909796] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.595078] random: sshd: uninitialized urandom read (32 bytes read) [ 24.930385] random: sshd: uninitialized urandom read (32 bytes read) [ 25.841904] random: sshd: uninitialized urandom read (32 bytes read) [ 40.033460] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.31' (ECDSA) to the list of known hosts. [ 45.500010] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 53.969350] ================================================================== [ 53.976911] BUG: KASAN: use-after-free in p9_conn_cancel+0x9fc/0xd30 [ 53.983421] Read of size 8 at addr ffff8801c3afdd20 by task kworker/1:3/2133 [ 53.990692] [ 53.992324] CPU: 1 PID: 2133 Comm: kworker/1:3 Not tainted 4.18.0-rc5+ #158 [ 53.999419] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.008788] Workqueue: events p9_poll_workfn [ 54.013220] Call Trace: [ 54.015800] dump_stack+0x1c9/0x2b4 executing program [ 54.019434] ? dump_stack_print_info.cold.2+0x52/0x52 [ 54.024639] ? printk+0xa7/0xcf [ 54.028105] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 54.033045] ? p9_conn_cancel+0x9fc/0xd30 [ 54.037232] print_address_description+0x6c/0x20b [ 54.042072] ? p9_conn_cancel+0x9fc/0xd30 [ 54.046213] kasan_report.cold.7+0x242/0x2fe [ 54.050640] __asan_report_load8_noabort+0x14/0x20 [ 54.055598] p9_conn_cancel+0x9fc/0xd30 [ 54.059605] ? p9_fd_cancelled+0x2f0/0x2f0 [ 54.063845] ? lock_downgrade+0x8f0/0x8f0 [ 54.068014] ? mark_held_locks+0xc9/0x160 [ 54.072164] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 54.076740] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 54.082274] ? generic_pipe_buf_confirm+0x10/0x10 [ 54.087124] p9_poll_workfn+0x4b2/0x6d0 [ 54.091102] ? p9_read_work+0x1060/0x1060 [ 54.095263] ? graph_lock+0x170/0x170 [ 54.099059] ? lock_acquire+0x1e4/0x540 [ 54.103039] ? process_one_work+0xb9b/0x1ba0 [ 54.107716] ? kasan_check_read+0x11/0x20 [ 54.111888] ? __lock_is_held+0xb5/0x140 [ 54.115973] process_one_work+0xc73/0x1ba0 [ 54.120218] ? trace_hardirqs_on+0x10/0x10 [ 54.124477] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 54.129769] ? __sched_text_start+0x8/0x8 [ 54.133919] ? lock_downgrade+0x8f0/0x8f0 [ 54.138069] ? graph_lock+0x170/0x170 [ 54.141879] ? graph_lock+0x170/0x170 [ 54.145722] ? lock_acquire+0x1e4/0x540 [ 54.149698] ? worker_thread+0x3dc/0x13c0 [ 54.153836] ? lock_downgrade+0x8f0/0x8f0 [ 54.158642] ? lock_release+0xa30/0xa30 [ 54.162612] ? kasan_check_read+0x11/0x20 [ 54.166779] ? do_raw_spin_unlock+0xa7/0x2f0 [ 54.171192] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 54.175789] ? kasan_check_write+0x14/0x20 [ 54.180033] ? do_raw_spin_lock+0xc1/0x200 [ 54.184295] worker_thread+0x189/0x13c0 [ 54.188291] ? process_one_work+0x1ba0/0x1ba0 [ 54.192786] ? graph_lock+0x170/0x170 [ 54.196591] ? graph_lock+0x170/0x170 [ 54.200400] ? find_held_lock+0x36/0x1c0 [ 54.204469] ? find_held_lock+0x36/0x1c0 [ 54.208652] ? kasan_check_read+0x11/0x20 [ 54.212789] ? do_raw_spin_unlock+0xa7/0x2f0 [ 54.217201] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 54.222291] ? __kthread_parkme+0x58/0x1b0 [ 54.226531] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 54.231555] ? trace_hardirqs_on+0xd/0x10 [ 54.235698] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 54.241228] ? __kthread_parkme+0x106/0x1b0 [ 54.245541] kthread+0x345/0x410 [ 54.248903] ? process_one_work+0x1ba0/0x1ba0 [ 54.253524] ? kthread_bind+0x40/0x40 [ 54.257341] ret_from_fork+0x3a/0x50 [ 54.261230] [ 54.262853] Allocated by task 8226: [ 54.266492] save_stack+0x43/0xd0 [ 54.269947] kasan_kmalloc+0xc4/0xe0 [ 54.273745] kmem_cache_alloc_trace+0x152/0x780 [ 54.278594] p9_fd_create+0x1a7/0x3f0 [ 54.282409] p9_client_create+0x8ed/0x1770 [ 54.286655] v9fs_session_init+0x21a/0x1a80 [ 54.290976] v9fs_mount+0x7c/0x900 [ 54.294507] mount_fs+0xae/0x328 [ 54.297886] vfs_kern_mount.part.34+0xdc/0x4e0 [ 54.302469] do_mount+0x581/0x30e0 [ 54.305999] ksys_mount+0x12d/0x140 [ 54.309630] __x64_sys_mount+0xbe/0x150 [ 54.313606] do_syscall_64+0x1b9/0x820 [ 54.317492] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.323374] [ 54.325014] Freed by task 8226: [ 54.328305] save_stack+0x43/0xd0 [ 54.331763] __kasan_slab_free+0x11a/0x170 [ 54.335983] kasan_slab_free+0xe/0x10 [ 54.339770] kfree+0xd9/0x260 [ 54.343044] p9_fd_close+0x416/0x5b0 [ 54.346755] p9_client_create+0xa9a/0x1770 [ 54.351010] v9fs_session_init+0x21a/0x1a80 [ 54.355340] v9fs_mount+0x7c/0x900 [ 54.358886] mount_fs+0xae/0x328 [ 54.362258] vfs_kern_mount.part.34+0xdc/0x4e0 [ 54.366840] do_mount+0x581/0x30e0 [ 54.370385] ksys_mount+0x12d/0x140 [ 54.374288] __x64_sys_mount+0xbe/0x150 [ 54.378267] do_syscall_64+0x1b9/0x820 [ 54.382156] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.387332] [ 54.388962] The buggy address belongs to the object at ffff8801c3afdd00 [ 54.388962] which belongs to the cache kmalloc-512 of size 512 [ 54.401633] The buggy address is located 32 bytes inside of [ 54.401633] 512-byte region [ffff8801c3afdd00, ffff8801c3afdf00) [ 54.413419] The buggy address belongs to the page: [ 54.418353] page:ffffea00070ebf40 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0 [ 54.426489] flags: 0x2fffc0000000100(slab) [ 54.430714] raw: 02fffc0000000100 ffffea0006e3a688 ffffea0006d7c808 ffff8801da800940 [ 54.438608] raw: 0000000000000000 ffff8801c3afd080 0000000100000006 0000000000000000 [ 54.446486] page dumped because: kasan: bad access detected [ 54.452179] [ 54.453791] Memory state around the buggy address: [ 54.458716] ffff8801c3afdc00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 54.466067] ffff8801c3afdc80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 54.473430] >ffff8801c3afdd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 54.480793] ^ [ 54.485211] ffff8801c3afdd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 54.492580] ffff8801c3afde00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 54.499944] ================================================================== [ 54.507293] Disabling lock debugging due to kernel taint [ 54.513125] Kernel panic - not syncing: panic_on_warn set ... [ 54.513125] [ 54.520514] CPU: 1 PID: 2133 Comm: kworker/1:3 Tainted: G B 4.18.0-rc5+ #158 [ 54.529005] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.538369] Workqueue: events p9_poll_workfn [ 54.542767] Call Trace: [ 54.545365] dump_stack+0x1c9/0x2b4 [ 54.548994] ? dump_stack_print_info.cold.2+0x52/0x52 [ 54.554184] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 54.558931] panic+0x238/0x4e7 [ 54.562114] ? add_taint.cold.5+0x16/0x16 [ 54.566268] ? do_raw_spin_unlock+0xa7/0x2f0 [ 54.570684] ? p9_conn_cancel+0x9fc/0xd30 [ 54.574837] kasan_end_report+0x47/0x4f [ 54.578826] kasan_report.cold.7+0x76/0x2fe [ 54.583166] __asan_report_load8_noabort+0x14/0x20 [ 54.588092] p9_conn_cancel+0x9fc/0xd30 [ 54.592066] ? p9_fd_cancelled+0x2f0/0x2f0 [ 54.596309] ? lock_downgrade+0x8f0/0x8f0 [ 54.600459] ? mark_held_locks+0xc9/0x160 [ 54.604615] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 54.609206] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 54.614756] ? generic_pipe_buf_confirm+0x10/0x10 [ 54.619605] p9_poll_workfn+0x4b2/0x6d0 [ 54.623580] ? p9_read_work+0x1060/0x1060 [ 54.627720] ? graph_lock+0x170/0x170 [ 54.631513] ? lock_acquire+0x1e4/0x540 [ 54.635482] ? process_one_work+0xb9b/0x1ba0 [ 54.639895] ? kasan_check_read+0x11/0x20 [ 54.644059] ? __lock_is_held+0xb5/0x140 [ 54.648120] process_one_work+0xc73/0x1ba0 [ 54.652347] ? trace_hardirqs_on+0x10/0x10 [ 54.656575] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 54.661248] ? __sched_text_start+0x8/0x8 [ 54.665395] ? lock_downgrade+0x8f0/0x8f0 [ 54.669550] ? graph_lock+0x170/0x170 [ 54.673339] ? graph_lock+0x170/0x170 [ 54.677143] ? lock_acquire+0x1e4/0x540 [ 54.681115] ? worker_thread+0x3dc/0x13c0 [ 54.685262] ? lock_downgrade+0x8f0/0x8f0 [ 54.689420] ? lock_release+0xa30/0xa30 [ 54.693395] ? kasan_check_read+0x11/0x20 [ 54.697546] ? do_raw_spin_unlock+0xa7/0x2f0 [ 54.701979] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 54.706565] ? kasan_check_write+0x14/0x20 [ 54.710794] ? do_raw_spin_lock+0xc1/0x200 [ 54.715028] worker_thread+0x189/0x13c0 [ 54.719010] ? process_one_work+0x1ba0/0x1ba0 [ 54.723603] ? graph_lock+0x170/0x170 [ 54.727399] ? graph_lock+0x170/0x170 [ 54.731191] ? find_held_lock+0x36/0x1c0 [ 54.735261] ? find_held_lock+0x36/0x1c0 [ 54.739338] ? kasan_check_read+0x11/0x20 [ 54.743490] ? do_raw_spin_unlock+0xa7/0x2f0 [ 54.747908] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 54.753015] ? __kthread_parkme+0x58/0x1b0 [ 54.757258] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 54.762278] ? trace_hardirqs_on+0xd/0x10 [ 54.766419] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 54.771964] ? __kthread_parkme+0x106/0x1b0 [ 54.776311] kthread+0x345/0x410 [ 54.779674] ? process_one_work+0x1ba0/0x1ba0 [ 54.784168] ? kthread_bind+0x40/0x40 [ 54.787961] ret_from_fork+0x3a/0x50 [ 54.792228] Dumping ftrace buffer: [ 54.795775] (ftrace buffer empty) [ 54.799470] Kernel Offset: disabled [ 54.803081] Rebooting in 86400 seconds..