[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.751451] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.485254] random: sshd: uninitialized urandom read (32 bytes read) [ 20.750647] random: sshd: uninitialized urandom read (32 bytes read) [ 21.470971] random: sshd: uninitialized urandom read (32 bytes read) [ 21.610178] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.45' (ECDSA) to the list of known hosts. [ 27.119222] 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 [ 28.865836] ================================================================== [ 28.873250] BUG: KASAN: use-after-free in work_is_static_object+0x39/0x40 [ 28.880226] Read of size 8 at addr ffff8801d8f0e1a0 by task kworker/1:2/2136 [ 28.880234] [ 28.889093] CPU: 1 PID: 2136 Comm: kworker/1:2 Not tainted 4.18.0-rc4-next-20180710+ #3 [ 28.889104] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.906647] Workqueue: events p9_poll_workfn [ 28.906661] Call Trace: executing program executing program executing program executing program [ 28.906677] dump_stack+0x1c9/0x2b4 [ 28.906688] ? dump_stack_print_info.cold.2+0x52/0x52 [ 28.906704] ? printk+0xa7/0xcf [ 28.925722] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 28.925736] ? work_is_static_object+0x39/0x40 [ 28.925753] print_address_description+0x6c/0x20b [ 28.939895] ? work_is_static_object+0x39/0x40 [ 28.939912] kasan_report.cold.7+0x242/0x30d [ 28.948883] __asan_report_load8_noabort+0x14/0x20 [ 28.948900] work_is_static_object+0x39/0x40 [ 28.958233] debug_object_activate+0x2fc/0x690 [ 28.958247] ? __wake_up_common+0x740/0x740 [ 28.958263] ? debug_object_assert_init+0x4b0/0x4b0 [ 28.958283] __queue_work+0x1ca/0x1410 [ 28.958295] ? __wake_up+0xe/0x10 [ 28.958310] ? p9_client_cb+0x62/0x80 [ 28.958330] ? flush_rcu_work+0x90/0x90 [ 28.958345] ? p9_fd_cancelled+0x2f0/0x2f0 [ 28.958359] ? inotify_poll+0xc5/0xf0 [ 28.958372] ? lock_downgrade+0x8f0/0x8f0 [ 28.958391] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.005375] ? kasan_check_read+0x11/0x20 [ 29.005394] ? do_raw_spin_unlock+0xa7/0x2f0 [ 29.014194] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 29.014213] ? kasan_check_write+0x14/0x20 [ 29.023017] ? do_raw_spin_lock+0xc1/0x200 [ 29.023037] ? _raw_spin_unlock+0x22/0x30 [ 29.031406] queue_work_on+0x19a/0x1e0 [ 29.031423] p9_poll_workfn+0x55e/0x6d0 [ 29.039274] ? p9_read_work+0x1060/0x1060 [ 29.039291] ? lock_acquire+0x1e4/0x540 [ 29.039309] ? process_one_work+0xb9b/0x1ba0 [ 29.051801] ? kasan_check_read+0x11/0x20 [ 29.051820] ? lock_release+0xa30/0xa30 [ 29.059935] ? kasan_check_read+0x11/0x20 [ 29.059953] ? do_raw_spin_unlock+0xa7/0x2f0 [ 29.068506] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 29.068526] ? read_word_at_a_time+0x20/0x20 [ 29.077490] ? compat_start_thread+0x80/0x80 [ 29.077507] process_one_work+0xc73/0x1ba0 [ 29.077522] ? trace_hardirqs_on+0x10/0x10 [ 29.077538] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 29.095108] ? lock_repin_lock+0x430/0x430 [ 29.095132] ? __sched_text_start+0x8/0x8 [ 29.103592] ? lock_downgrade+0x8f0/0x8f0 [ 29.103609] ? lock_acquire+0x1e4/0x540 [ 29.103623] ? __update_idle_core+0x304/0x610 [ 29.103642] ? kasan_check_write+0x14/0x20 [ 29.103658] ? __mutex_unlock_slowpath+0x197/0x8c0 [ 29.103672] ? lock_downgrade+0x8f0/0x8f0 [ 29.103687] ? lock_acquire+0x1e4/0x540 [ 29.103700] ? worker_thread+0x3dc/0x13c0 [ 29.103712] ? lock_downgrade+0x8f0/0x8f0 [ 29.103722] ? lock_release+0xa30/0xa30 [ 29.103731] ? kasan_check_read+0x11/0x20 [ 29.103741] ? do_raw_spin_unlock+0xa7/0x2f0 [ 29.103749] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 29.103763] ? kasan_check_write+0x14/0x20 [ 29.103774] ? do_raw_spin_lock+0xc1/0x200 [ 29.103789] worker_thread+0x189/0x13c0 [ 29.103806] ? process_one_work+0x1ba0/0x1ba0 [ 29.103824] ? remove_entity_load_avg+0x1c4/0x260 [ 29.103837] ? lock_downgrade+0x8f0/0x8f0 [ 29.103856] ? lock_acquire+0x1e4/0x540 [ 29.103867] ? __kthread_parkme+0xd7/0x1b0 [ 29.103884] ? kasan_check_read+0x11/0x20 [ 29.103895] ? do_raw_spin_unlock+0xa7/0x2f0 [ 29.103910] ? kasan_check_write+0x14/0x20 [ 29.103925] ? trace_hardirqs_on+0xd/0x10 [ 29.103942] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 29.103952] ? __kthread_parkme+0x106/0x1b0 [ 29.103964] kthread+0x345/0x410 [ 29.103976] ? process_one_work+0x1ba0/0x1ba0 [ 29.103986] ? kthread_bind+0x40/0x40 [ 29.104000] ret_from_fork+0x3a/0x50 [ 29.104011] [ 29.104019] Allocated by task 4476: [ 29.104033] save_stack+0x43/0xd0 [ 29.104044] kasan_kmalloc+0xc4/0xe0 [ 29.104056] kmem_cache_alloc_trace+0x152/0x780 [ 29.104068] p9_fd_create+0x1a7/0x3f0 [ 29.104078] p9_client_create+0x915/0x16c9 [ 29.104088] v9fs_session_init+0x21a/0x1a80 [ 29.104100] v9fs_mount+0x7c/0x900 [ 29.104114] legacy_get_tree+0x118/0x440 [ 29.104127] vfs_get_tree+0x1cb/0x5c0 [ 29.104139] do_mount+0x6c1/0x1fb0 [ 29.104148] ksys_mount+0x12d/0x140 [ 29.104158] __x64_sys_mount+0xbe/0x150 [ 29.104173] do_syscall_64+0x1b9/0x820 [ 29.291600] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.291607] [ 29.298407] Freed by task 4476: [ 29.298425] save_stack+0x43/0xd0 [ 29.298437] __kasan_slab_free+0x11a/0x170 [ 29.298446] kasan_slab_free+0xe/0x10 [ 29.298456] kfree+0xd9/0x260 [ 29.298468] p9_fd_close+0x416/0x5b0 [ 29.298477] p9_client_create+0xac2/0x16c9 [ 29.298488] v9fs_session_init+0x21a/0x1a80 [ 29.298500] v9fs_mount+0x7c/0x900 [ 29.298514] legacy_get_tree+0x118/0x440 [ 29.298526] vfs_get_tree+0x1cb/0x5c0 [ 29.298536] do_mount+0x6c1/0x1fb0 [ 29.298547] ksys_mount+0x12d/0x140 [ 29.298558] __x64_sys_mount+0xbe/0x150 [ 29.298569] do_syscall_64+0x1b9/0x820 [ 29.298580] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.298583] [ 29.298591] The buggy address belongs to the object at ffff8801d8f0e080 [ 29.298591] which belongs to the cache kmalloc-512 of size 512 [ 29.298601] The buggy address is located 288 bytes inside of [ 29.298601] 512-byte region [ffff8801d8f0e080, ffff8801d8f0e280) [ 29.298604] The buggy address belongs to the page: [ 29.298615] page:ffffea000763c380 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0 [ 29.298625] flags: 0x2fffc0000000100(slab) [ 29.298642] raw: 02fffc0000000100 ffffea000763c548 ffffea0007626808 ffff8801da800940 [ 29.298657] raw: 0000000000000000 ffff8801d8f0e080 0000000100000006 0000000000000000 [ 29.298661] page dumped because: kasan: bad access detected [ 29.298663] [ 29.298666] Memory state around the buggy address: [ 29.298674] ffff8801d8f0e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.298684] ffff8801d8f0e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.446297] >ffff8801d8f0e180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.446302] ^ [ 29.446312] ffff8801d8f0e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.446321] ffff8801d8f0e280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 29.446326] ================================================================== [ 29.446333] Kernel panic - not syncing: panic_on_warn set ... [ 29.446333] [ 29.446350] CPU: 1 PID: 2136 Comm: kworker/1:2 Tainted: G B 4.18.0-rc4-next-20180710+ #3 [ 29.446357] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.446376] Workqueue: events p9_poll_workfn [ 29.446383] Call Trace: [ 29.446399] dump_stack+0x1c9/0x2b4 [ 29.446414] ? dump_stack_print_info.cold.2+0x52/0x52 [ 29.446431] ? lock_downgrade+0x8f0/0x8f0 [ 29.446444] ? work_is_static_object+0x39/0x40 [ 29.446461] panic+0x238/0x4e7 [ 29.446474] ? add_taint.cold.5+0x16/0x16 [ 29.446491] ? print_shadow_for_address+0xba/0x116 [ 29.446504] ? do_raw_spin_unlock+0xa7/0x2f0 [ 29.446517] ? work_is_static_object+0x39/0x40 [ 29.446529] kasan_end_report+0x47/0x4f [ 29.446541] kasan_report.cold.7+0x76/0x30d [ 29.446556] __asan_report_load8_noabort+0x14/0x20 [ 29.446568] work_is_static_object+0x39/0x40 [ 29.446581] debug_object_activate+0x2fc/0x690 [ 29.446593] ? __wake_up_common+0x740/0x740 [ 29.446610] ? debug_object_assert_init+0x4b0/0x4b0 [ 29.446629] __queue_work+0x1ca/0x1410 [ 29.446640] ? __wake_up+0xe/0x10 [ 29.446654] ? p9_client_cb+0x62/0x80 [ 29.446668] ? flush_rcu_work+0x90/0x90 [ 29.446682] ? p9_fd_cancelled+0x2f0/0x2f0 [ 29.446696] ? inotify_poll+0xc5/0xf0 [ 29.446710] ? lock_downgrade+0x8f0/0x8f0 [ 29.446727] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.446742] ? kasan_check_read+0x11/0x20 [ 29.446754] ? do_raw_spin_unlock+0xa7/0x2f0 [ 29.446767] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 29.446782] ? kasan_check_write+0x14/0x20 [ 29.446794] ? do_raw_spin_lock+0xc1/0x200 [ 29.446809] ? _raw_spin_unlock+0x22/0x30 [ 29.446823] queue_work_on+0x19a/0x1e0 [ 29.446837] p9_poll_workfn+0x55e/0x6d0 [ 29.446852] ? p9_read_work+0x1060/0x1060 [ 29.446869] ? lock_acquire+0x1e4/0x540 [ 29.446881] ? process_one_work+0xb9b/0x1ba0 [ 29.446895] ? kasan_check_read+0x11/0x20 [ 29.446910] ? lock_release+0xa30/0xa30 [ 29.446923] ? kasan_check_read+0x11/0x20 [ 29.446936] ? do_raw_spin_unlock+0xa7/0x2f0 [ 29.446948] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 29.446963] ? read_word_at_a_time+0x20/0x20 [ 29.446978] ? compat_start_thread+0x80/0x80 [ 29.446995] process_one_work+0xc73/0x1ba0 [ 29.447008] ? trace_hardirqs_on+0x10/0x10 [ 29.447026] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 29.447039] ? lock_repin_lock+0x430/0x430 [ 29.447062] ? __sched_text_start+0x8/0x8 [ 29.447075] ? lock_downgrade+0x8f0/0x8f0 [ 29.447092] ? lock_acquire+0x1e4/0x540 [ 29.447105] ? __update_idle_core+0x304/0x610 [ 29.447123] ? kasan_check_write+0x14/0x20 [ 29.447138] ? __mutex_unlock_slowpath+0x197/0x8c0 [ 29.447152] ? lock_downgrade+0x8f0/0x8f0 [ 29.447168] ? lock_acquire+0x1e4/0x540 [ 29.447181] ? worker_thread+0x3dc/0x13c0 [ 29.447195] ? lock_downgrade+0x8f0/0x8f0 [ 29.447211] ? lock_release+0xa30/0xa30 [ 29.447225] ? kasan_check_read+0x11/0x20 [ 29.447237] ? do_raw_spin_unlock+0xa7/0x2f0 [ 29.447249] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 29.447264] ? kasan_check_write+0x14/0x20 [ 29.447276] ? do_raw_spin_lock+0xc1/0x200 [ 29.447298] worker_thread+0x189/0x13c0 [ 29.447317] ? process_one_work+0x1ba0/0x1ba0 [ 29.447338] ? remove_entity_load_avg+0x1c4/0x260 [ 29.447351] ? lock_downgrade+0x8f0/0x8f0 [ 29.447371] ? lock_acquire+0x1e4/0x540 [ 29.447382] ? __kthread_parkme+0xd7/0x1b0 [ 29.447400] ? kasan_check_read+0x11/0x20 [ 29.447412] ? do_raw_spin_unlock+0xa7/0x2f0 [ 29.447428] ? kasan_check_write+0x14/0x20 [ 29.447444] ? trace_hardirqs_on+0xd/0x10 [ 29.447459] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 29.447470] ? __kthread_parkme+0x106/0x1b0 [ 29.447484] kthread+0x345/0x410 [ 29.447497] ? process_one_work+0x1ba0/0x1ba0 [ 29.447507] ? kthread_bind+0x40/0x40 [ 29.447521] ret_from_fork+0x3a/0x50 [ 29.448018] Dumping ftrace buffer: [ 29.448023] (ftrace buffer empty) [ 29.448027] Kernel Offset: disabled