[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.203835] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.538944] random: sshd: uninitialized urandom read (32 bytes read) [ 23.790719] random: sshd: uninitialized urandom read (32 bytes read) [ 24.659269] random: sshd: uninitialized urandom read (32 bytes read) [ 29.023168] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.48' (ECDSA) to the list of known hosts. [ 34.484456] 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 [ 34.695996] ================================================================== [ 34.703507] BUG: KASAN: use-after-free in work_is_static_object+0x39/0x40 [ 34.710443] Read of size 8 at addr ffff8801d9650e60 by task kworker/1:1/27 [ 34.717461] [ 34.719077] CPU: 1 PID: 27 Comm: kworker/1:1 Not tainted 4.18.0-rc4+ #138 [ 34.725981] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.735333] Workqueue: events p9_poll_workfn [ 34.739736] Call Trace: [ 34.742309] dump_stack+0x1c9/0x2b4 [ 34.745935] ? dump_stack_print_info.cold.2+0x52/0x52 [ 34.751111] ? printk+0xa7/0xcf [ 34.754377] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 34.759124] ? work_is_static_object+0x39/0x40 [ 34.763690] print_address_description+0x6c/0x20b [ 34.768522] ? work_is_static_object+0x39/0x40 [ 34.773101] kasan_report.cold.7+0x242/0x2fe [ 34.777502] __asan_report_load8_noabort+0x14/0x20 [ 34.782427] work_is_static_object+0x39/0x40 [ 34.786831] debug_object_activate+0x2fc/0x690 [ 34.791408] ? __wake_up_common+0x740/0x740 [ 34.795716] ? debug_object_assert_init+0x4b0/0x4b0 [ 34.800730] ? mark_held_locks+0xc9/0x160 [ 34.804877] __queue_work+0x1ca/0x1410 [ 34.808751] ? __wake_up+0xe/0x10 [ 34.812198] ? p9_client_cb+0x62/0x80 [ 34.815985] ? flush_rcu_work+0x90/0x90 [ 34.819959] ? p9_fd_cancelled+0x2f0/0x2f0 [ 34.824180] ? dccp_close+0xe70/0xe70 [ 34.827970] ? lock_downgrade+0x8f0/0x8f0 [ 34.832108] ? sock_poll+0x274/0x4b0 [ 34.835819] ? mark_held_locks+0xc9/0x160 [ 34.839961] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 34.844533] queue_work_on+0x19a/0x1e0 [ 34.848417] p9_poll_workfn+0x55e/0x6d0 [ 34.852386] ? p9_read_work+0x1060/0x1060 [ 34.856521] ? graph_lock+0x170/0x170 [ 34.860309] ? lock_acquire+0x1e4/0x540 [ 34.864267] ? process_one_work+0xb9b/0x1ba0 [ 34.868673] ? kasan_check_read+0x11/0x20 [ 34.872810] ? __lock_is_held+0xb5/0x140 [ 34.876890] process_one_work+0xc73/0x1ba0 [ 34.881119] ? trace_hardirqs_on+0x10/0x10 [ 34.885347] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 34.890018] ? lock_repin_lock+0x430/0x430 [ 34.894270] ? __sched_text_start+0x8/0x8 [ 34.898403] ? lock_downgrade+0x8f0/0x8f0 [ 34.902547] ? prepare_to_swait_event+0xc0/0xc0 [ 34.907200] ? graph_lock+0x170/0x170 [ 34.911088] ? lock_acquire+0x1e4/0x540 [ 34.915052] ? worker_thread+0x3dc/0x13c0 [ 34.919186] ? lock_downgrade+0x8f0/0x8f0 [ 34.923321] ? lock_release+0xa30/0xa30 [ 34.927293] ? kasan_check_read+0x11/0x20 [ 34.931431] ? do_raw_spin_unlock+0xa7/0x2f0 [ 34.935825] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 34.940397] ? kasan_check_write+0x14/0x20 [ 34.944616] ? do_raw_spin_lock+0xc1/0x200 [ 34.948847] worker_thread+0x189/0x13c0 [ 34.952817] ? process_one_work+0x1ba0/0x1ba0 [ 34.957299] ? graph_lock+0x170/0x170 [ 34.961087] ? graph_lock+0x170/0x170 [ 34.964872] ? find_held_lock+0x36/0x1c0 [ 34.968930] ? find_held_lock+0x36/0x1c0 [ 34.972984] ? lock_downgrade+0x8f0/0x8f0 [ 34.977139] ? kasan_check_read+0x11/0x20 [ 34.981273] ? do_raw_spin_unlock+0xa7/0x2f0 [ 34.985676] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 34.990782] ? __kthread_parkme+0x58/0x1b0 [ 34.995008] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 35.000024] ? trace_hardirqs_on+0xd/0x10 [ 35.004162] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 35.009683] ? __kthread_parkme+0x106/0x1b0 [ 35.013995] kthread+0x345/0x410 [ 35.017349] ? process_one_work+0x1ba0/0x1ba0 [ 35.021832] ? kthread_bind+0x40/0x40 [ 35.025633] ret_from_fork+0x3a/0x50 [ 35.029350] [ 35.030979] Allocated by task 4627: [ 35.034601] save_stack+0x43/0xd0 [ 35.038046] kasan_kmalloc+0xc4/0xe0 [ 35.041747] kmem_cache_alloc_trace+0x152/0x780 [ 35.046432] p9_fd_create+0x1a7/0x3f0 [ 35.050217] p9_client_create+0x915/0x16c9 [ 35.054450] v9fs_session_init+0x21a/0x1a80 [ 35.058753] v9fs_mount+0x7c/0x900 [ 35.062277] mount_fs+0xae/0x328 [ 35.065626] vfs_kern_mount.part.34+0xdc/0x4e0 [ 35.070191] do_mount+0x581/0x30e0 [ 35.073712] ksys_mount+0x12d/0x140 [ 35.077321] __x64_sys_mount+0xbe/0x150 [ 35.081294] do_syscall_64+0x1b9/0x820 [ 35.085178] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 35.090347] [ 35.091958] Freed by task 4627: [ 35.095236] save_stack+0x43/0xd0 [ 35.098673] __kasan_slab_free+0x11a/0x170 [ 35.102895] kasan_slab_free+0xe/0x10 [ 35.106686] kfree+0xd9/0x260 [ 35.109783] p9_fd_close+0x416/0x5b0 [ 35.113663] p9_client_create+0xac2/0x16c9 [ 35.117885] v9fs_session_init+0x21a/0x1a80 [ 35.122204] v9fs_mount+0x7c/0x900 [ 35.125737] mount_fs+0xae/0x328 [ 35.129085] vfs_kern_mount.part.34+0xdc/0x4e0 [ 35.133651] do_mount+0x581/0x30e0 [ 35.137186] ksys_mount+0x12d/0x140 [ 35.140794] __x64_sys_mount+0xbe/0x150 [ 35.144753] do_syscall_64+0x1b9/0x820 [ 35.148624] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 35.155194] [ 35.156809] The buggy address belongs to the object at ffff8801d9650d40 [ 35.156809] which belongs to the cache kmalloc-512 of size 512 [ 35.169463] The buggy address is located 288 bytes inside of [ 35.169463] 512-byte region [ffff8801d9650d40, ffff8801d9650f40) [ 35.181324] The buggy address belongs to the page: [ 35.186241] page:ffffea0007659400 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0 [ 35.194380] flags: 0x2fffc0000000100(slab) [ 35.198602] raw: 02fffc0000000100 ffffea0007645fc8 ffffea0006bf3648 ffff8801da800940 [ 35.206484] raw: 0000000000000000 ffff8801d96500c0 0000000100000006 0000000000000000 [ 35.214346] page dumped because: kasan: bad access detected [ 35.220042] [ 35.221651] Memory state around the buggy address: [ 35.226567] ffff8801d9650d00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 35.233922] ffff8801d9650d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.241267] >ffff8801d9650e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.248620] ^ [ 35.255115] ffff8801d9650e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.262467] ffff8801d9650f00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 35.269817] ================================================================== [ 35.277165] Disabling lock debugging due to kernel taint [ 35.282600] Kernel panic - not syncing: panic_on_warn set ... [ 35.282600] [ 35.289952] CPU: 1 PID: 27 Comm: kworker/1:1 Tainted: G B 4.18.0-rc4+ #138 [ 35.298261] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.307623] Workqueue: events p9_poll_workfn [ 35.312025] Call Trace: [ 35.314597] dump_stack+0x1c9/0x2b4 [ 35.318223] ? dump_stack_print_info.cold.2+0x52/0x52 [ 35.323418] ? lock_downgrade+0x8f0/0x8f0 [ 35.327574] panic+0x238/0x4e7 [ 35.330752] ? add_taint.cold.5+0x16/0x16 [ 35.334889] ? add_taint.cold.5+0x5/0x16 [ 35.338942] ? do_raw_spin_unlock+0xa7/0x2f0 [ 35.343335] ? work_is_static_object+0x39/0x40 [ 35.347903] kasan_end_report+0x47/0x4f [ 35.351863] kasan_report.cold.7+0x76/0x2fe [ 35.356168] __asan_report_load8_noabort+0x14/0x20 [ 35.361082] work_is_static_object+0x39/0x40 [ 35.365474] debug_object_activate+0x2fc/0x690 [ 35.370043] ? __wake_up_common+0x740/0x740 [ 35.374372] ? debug_object_assert_init+0x4b0/0x4b0 [ 35.379385] ? mark_held_locks+0xc9/0x160 [ 35.383523] __queue_work+0x1ca/0x1410 [ 35.387394] ? __wake_up+0xe/0x10 [ 35.390833] ? p9_client_cb+0x62/0x80 [ 35.394621] ? flush_rcu_work+0x90/0x90 [ 35.398581] ? p9_fd_cancelled+0x2f0/0x2f0 [ 35.402814] ? dccp_close+0xe70/0xe70 [ 35.406607] ? lock_downgrade+0x8f0/0x8f0 [ 35.410740] ? sock_poll+0x274/0x4b0 [ 35.414448] ? mark_held_locks+0xc9/0x160 [ 35.418679] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 35.423249] queue_work_on+0x19a/0x1e0 [ 35.427124] p9_poll_workfn+0x55e/0x6d0 [ 35.431085] ? p9_read_work+0x1060/0x1060 [ 35.435228] ? graph_lock+0x170/0x170 [ 35.439019] ? lock_acquire+0x1e4/0x540 [ 35.443000] ? process_one_work+0xb9b/0x1ba0 [ 35.452209] ? kasan_check_read+0x11/0x20 [ 35.457990] ? __lock_is_held+0xb5/0x140 [ 35.462096] process_one_work+0xc73/0x1ba0 [ 35.467009] ? trace_hardirqs_on+0x10/0x10 [ 35.471343] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 35.476001] ? lock_repin_lock+0x430/0x430 [ 35.480238] ? __sched_text_start+0x8/0x8 [ 35.484379] ? lock_downgrade+0x8f0/0x8f0 [ 35.488533] ? prepare_to_swait_event+0xc0/0xc0 [ 35.493186] ? graph_lock+0x170/0x170 [ 35.496981] ? lock_acquire+0x1e4/0x540 [ 35.500955] ? worker_thread+0x3dc/0x13c0 [ 35.505099] ? lock_downgrade+0x8f0/0x8f0 [ 35.509232] ? lock_release+0xa30/0xa30 [ 35.513190] ? kasan_check_read+0x11/0x20 [ 35.517330] ? do_raw_spin_unlock+0xa7/0x2f0 [ 35.521733] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 35.526297] ? kasan_check_write+0x14/0x20 [ 35.530522] ? do_raw_spin_lock+0xc1/0x200 [ 35.534738] worker_thread+0x189/0x13c0 [ 35.538702] ? process_one_work+0x1ba0/0x1ba0 [ 35.543177] ? graph_lock+0x170/0x170 [ 35.546961] ? graph_lock+0x170/0x170 [ 35.550752] ? find_held_lock+0x36/0x1c0 [ 35.554797] ? find_held_lock+0x36/0x1c0 [ 35.558840] ? lock_downgrade+0x8f0/0x8f0 [ 35.562972] ? kasan_check_read+0x11/0x20 [ 35.567113] ? do_raw_spin_unlock+0xa7/0x2f0 [ 35.571515] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 35.576607] ? __kthread_parkme+0x58/0x1b0 [ 35.580824] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 35.585834] ? trace_hardirqs_on+0xd/0x10 [ 35.589984] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 35.595504] ? __kthread_parkme+0x106/0x1b0 [ 35.599819] kthread+0x345/0x410 [ 35.603168] ? process_one_work+0x1ba0/0x1ba0 [ 35.607643] ? kthread_bind+0x40/0x40 [ 35.611433] ret_from_fork+0x3a/0x50 [ 35.615593] Dumping ftrace buffer: [ 35.619111] (ftrace buffer empty) [ 35.622799] Kernel Offset: disabled [ 35.626419] Rebooting in 86400 seconds..