[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.054518] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.201498] random: sshd: uninitialized urandom read (32 bytes read) [ 24.547298] random: sshd: uninitialized urandom read (32 bytes read) [ 25.526870] random: sshd: uninitialized urandom read (32 bytes read) [ 25.688990] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.17' (ECDSA) to the list of known hosts. [ 31.138816] 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 [ 38.286308] ================================================================== [ 38.293888] BUG: KASAN: use-after-free in p9_conn_cancel+0x9fc/0xd30 [ 38.300632] Read of size 8 at addr ffff8801d7b7fd20 by task kworker/1:0/19 [ 38.309530] [ 38.311151] CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 4.18.0-rc5+ #158 [ 38.318249] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.327688] Workqueue: events p9_poll_workfn [ 38.332349] Call Trace: [ 38.334940] dump_stack+0x1c9/0x2b4 [ 38.338551] ? dump_stack_print_info.cold.2+0x52/0x52 [ 38.343727] ? printk+0xa7/0xcf [ 38.346994] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 38.351738] ? p9_conn_cancel+0x9fc/0xd30 [ 38.355886] print_address_description+0x6c/0x20b [ 38.360906] ? p9_conn_cancel+0x9fc/0xd30 [ 38.365066] kasan_report.cold.7+0x242/0x2fe [ 38.369481] __asan_report_load8_noabort+0x14/0x20 [ 38.374421] p9_conn_cancel+0x9fc/0xd30 [ 38.378574] ? p9_fd_cancelled+0x2f0/0x2f0 [ 38.382817] ? lock_downgrade+0x8f0/0x8f0 [ 38.386962] ? mark_held_locks+0xc9/0x160 [ 38.391095] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 38.395671] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 38.401192] ? generic_pipe_buf_confirm+0x10/0x10 [ 38.406024] p9_poll_workfn+0x4b2/0x6d0 [ 38.410006] ? p9_read_work+0x1060/0x1060 [ 38.414142] ? graph_lock+0x170/0x170 [ 38.417932] ? lock_acquire+0x1e4/0x540 [ 38.421891] ? process_one_work+0xb9b/0x1ba0 [ 38.426299] ? kasan_check_read+0x11/0x20 [ 38.430441] ? __lock_is_held+0xb5/0x140 [ 38.434495] process_one_work+0xc73/0x1ba0 [ 38.438739] ? trace_hardirqs_on+0x10/0x10 [ 38.442958] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 38.447743] ? lock_repin_lock+0x430/0x430 [ 38.452065] ? __sched_text_start+0x8/0x8 [ 38.456218] ? graph_lock+0x170/0x170 [ 38.460011] ? lock_downgrade+0x8f0/0x8f0 [ 38.464149] ? kasan_check_read+0x11/0x20 [ 38.468281] ? do_raw_spin_unlock+0xa7/0x2f0 [ 38.472884] ? lock_acquire+0x1e4/0x540 [ 38.476862] ? worker_thread+0x3dc/0x13c0 [ 38.481009] ? lock_downgrade+0x8f0/0x8f0 [ 38.485150] ? lock_release+0xa30/0xa30 [ 38.489120] ? kasan_check_read+0x11/0x20 [ 38.493282] ? do_raw_spin_unlock+0xa7/0x2f0 [ 38.497688] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 38.502347] ? kasan_check_write+0x14/0x20 [ 38.506586] ? do_raw_spin_lock+0xc1/0x200 [ 38.510825] worker_thread+0x189/0x13c0 [ 38.514816] ? process_one_work+0x1ba0/0x1ba0 [ 38.519355] ? graph_lock+0x170/0x170 [ 38.523153] ? graph_lock+0x170/0x170 [ 38.526962] ? find_held_lock+0x36/0x1c0 [ 38.531035] ? find_held_lock+0x36/0x1c0 [ 38.535096] ? lock_downgrade+0x8f0/0x8f0 [ 38.539236] ? kasan_check_read+0x11/0x20 [ 38.543394] ? do_raw_spin_unlock+0xa7/0x2f0 [ 38.547817] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 38.559486] ? __kthread_parkme+0x58/0x1b0 [ 38.563928] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 38.568984] ? trace_hardirqs_on+0xd/0x10 [ 38.573155] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 38.578698] ? __kthread_parkme+0x106/0x1b0 [ 38.583028] kthread+0x345/0x410 [ 38.586385] ? process_one_work+0x1ba0/0x1ba0 [ 38.590861] ? kthread_bind+0x40/0x40 [ 38.594686] ret_from_fork+0x3a/0x50 [ 38.598434] [ 38.600078] Allocated by task 4950: [ 38.603694] save_stack+0x43/0xd0 [ 38.607145] kasan_kmalloc+0xc4/0xe0 [ 38.610960] kmem_cache_alloc_trace+0x152/0x780 [ 38.618628] p9_fd_create+0x1a7/0x3f0 [ 38.622928] p9_client_create+0x8ed/0x1770 [ 38.627267] v9fs_session_init+0x21a/0x1a80 [ 38.632631] v9fs_mount+0x7c/0x900 [ 38.636164] mount_fs+0xae/0x328 [ 38.639518] vfs_kern_mount.part.34+0xdc/0x4e0 [ 38.645327] do_mount+0x581/0x30e0 [ 38.648913] ksys_mount+0x12d/0x140 [ 38.652999] __x64_sys_mount+0xbe/0x150 [ 38.656984] do_syscall_64+0x1b9/0x820 [ 38.660987] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.666170] [ 38.667796] Freed by task 4950: [ 38.671068] save_stack+0x43/0xd0 [ 38.674550] __kasan_slab_free+0x11a/0x170 [ 38.678975] kasan_slab_free+0xe/0x10 [ 38.682785] kfree+0xd9/0x260 [ 38.685930] p9_fd_close+0x416/0x5b0 [ 38.689738] p9_client_create+0xa9a/0x1770 [ 38.693980] v9fs_session_init+0x21a/0x1a80 [ 38.698296] v9fs_mount+0x7c/0x900 [ 38.704238] mount_fs+0xae/0x328 [ 38.707614] vfs_kern_mount.part.34+0xdc/0x4e0 [ 38.712299] do_mount+0x581/0x30e0 [ 38.715837] ksys_mount+0x12d/0x140 [ 38.719456] __x64_sys_mount+0xbe/0x150 [ 38.723417] do_syscall_64+0x1b9/0x820 [ 38.727293] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.732461] [ 38.734086] The buggy address belongs to the object at ffff8801d7b7fd00 [ 38.734086] which belongs to the cache kmalloc-512 of size 512 [ 38.746844] The buggy address is located 32 bytes inside of [ 38.746844] 512-byte region [ffff8801d7b7fd00, ffff8801d7b7ff00) [ 38.759062] The buggy address belongs to the page: [ 38.763978] page:ffffea00075edfc0 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0 [ 38.772124] flags: 0x2fffc0000000100(slab) [ 38.776366] raw: 02fffc0000000100 ffffea00075ec308 ffff8801da801748 ffff8801da800940 [ 38.784234] raw: 0000000000000000 ffff8801d7b7f080 0000000100000006 0000000000000000 [ 38.792105] page dumped because: kasan: bad access detected [ 38.797792] [ 38.799401] Memory state around the buggy address: [ 38.804314] ffff8801d7b7fc00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 38.811670] ffff8801d7b7fc80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 38.819034] >ffff8801d7b7fd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.826377] ^ [ 38.830764] ffff8801d7b7fd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program [ 38.838103] ffff8801d7b7fe00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.845449] ================================================================== [ 38.852814] Disabling lock debugging due to kernel taint [ 38.858463] Kernel panic - not syncing: panic_on_warn set ... [ 38.858463] [ 38.866007] CPU: 1 PID: 19 Comm: kworker/1:0 Tainted: G B 4.18.0-rc5+ #158 [ 38.875083] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.884897] Workqueue: events p9_poll_workfn [ 38.889317] Call Trace: [ 38.891909] dump_stack+0x1c9/0x2b4 [ 38.895536] ? dump_stack_print_info.cold.2+0x52/0x52 [ 38.900729] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 38.905476] panic+0x238/0x4e7 [ 38.908657] ? add_taint.cold.5+0x16/0x16 [ 38.912807] ? do_raw_spin_unlock+0xa7/0x2f0 [ 38.917211] ? p9_conn_cancel+0x9fc/0xd30 [ 38.921347] kasan_end_report+0x47/0x4f [ 38.925309] kasan_report.cold.7+0x76/0x2fe [ 38.929630] __asan_report_load8_noabort+0x14/0x20 [ 38.934551] p9_conn_cancel+0x9fc/0xd30 [ 38.938506] ? p9_fd_cancelled+0x2f0/0x2f0 [ 38.943540] ? lock_downgrade+0x8f0/0x8f0 [ 38.947682] ? mark_held_locks+0xc9/0x160 [ 38.951988] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 38.956586] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 38.962107] ? generic_pipe_buf_confirm+0x10/0x10 [ 38.966953] p9_poll_workfn+0x4b2/0x6d0 [ 38.970923] ? p9_read_work+0x1060/0x1060 [ 38.975056] ? graph_lock+0x170/0x170 [ 38.978847] ? lock_acquire+0x1e4/0x540 [ 38.982808] ? process_one_work+0xb9b/0x1ba0 [ 38.987371] ? kasan_check_read+0x11/0x20 [ 38.991645] ? __lock_is_held+0xb5/0x140 [ 38.995774] process_one_work+0xc73/0x1ba0 [ 39.000004] ? trace_hardirqs_on+0x10/0x10 [ 39.004238] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 39.009283] ? lock_repin_lock+0x430/0x430 [ 39.013512] ? __sched_text_start+0x8/0x8 [ 39.017768] ? graph_lock+0x170/0x170 [ 39.021666] ? lock_downgrade+0x8f0/0x8f0 [ 39.025806] ? kasan_check_read+0x11/0x20 [ 39.029946] ? do_raw_spin_unlock+0xa7/0x2f0 [ 39.034350] ? lock_acquire+0x1e4/0x540 [ 39.038311] ? worker_thread+0x3dc/0x13c0 [ 39.042441] ? lock_downgrade+0x8f0/0x8f0 [ 39.046580] ? lock_release+0xa30/0xa30 [ 39.050634] ? kasan_check_read+0x11/0x20 [ 39.054765] ? do_raw_spin_unlock+0xa7/0x2f0 [ 39.059169] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 39.063804] ? kasan_check_write+0x14/0x20 [ 39.068033] ? do_raw_spin_lock+0xc1/0x200 [ 39.072266] worker_thread+0x189/0x13c0 [ 39.076241] ? process_one_work+0x1ba0/0x1ba0 [ 39.080737] ? graph_lock+0x170/0x170 [ 39.084545] ? graph_lock+0x170/0x170 [ 39.088334] ? find_held_lock+0x36/0x1c0 [ 39.092380] ? find_held_lock+0x36/0x1c0 [ 39.096428] ? lock_downgrade+0x8f0/0x8f0 [ 39.100561] ? kasan_check_read+0x11/0x20 [ 39.104729] ? do_raw_spin_unlock+0xa7/0x2f0 [ 39.109753] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 39.114852] ? __kthread_parkme+0x58/0x1b0 [ 39.119093] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 39.124101] ? trace_hardirqs_on+0xd/0x10 [ 39.128366] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 39.133902] ? __kthread_parkme+0x106/0x1b0 [ 39.138227] kthread+0x345/0x410 [ 39.141787] ? process_one_work+0x1ba0/0x1ba0 [ 39.146454] ? kthread_bind+0x40/0x40 [ 39.150428] ret_from_fork+0x3a/0x50 [ 39.154647] Dumping ftrace buffer: [ 39.158177] (ftrace buffer empty) [ 39.161956] Kernel Offset: disabled [ 39.165651] Rebooting in 86400 seconds..