[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.274911] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.139319] random: sshd: uninitialized urandom read (32 bytes read) [ 24.765890] random: sshd: uninitialized urandom read (32 bytes read) [ 25.603389] random: sshd: uninitialized urandom read (32 bytes read) [ 25.727979] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.7' (ECDSA) to the list of known hosts. [ 31.164282] 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 [ 31.373149] ================================================================== [ 31.380550] BUG: KASAN: use-after-free in work_is_static_object+0x39/0x40 [ 31.387460] Read of size 8 at addr ffff8801c16412a0 by task kworker/1:2/3812 [ 31.394614] [ 31.396216] CPU: 1 PID: 3812 Comm: kworker/1:2 Not tainted 4.9.113-g47bbcd6 #10 [ 31.403633] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.412969] Workqueue: events p9_poll_workfn [ 31.417482] ffff8801b4a8f9c8 ffffffff81eb32a9 ffffea0007059000 ffff8801c16412a0 [ 31.425467] 0000000000000000 ffff8801c16412a0 0000000000000000 ffff8801b4a8fa00 [ 31.433438] ffffffff81567bd9 ffff8801c16412a0 0000000000000008 0000000000000000 [ 31.441413] Call Trace: [ 31.443981] [] dump_stack+0xc1/0x128 [ 31.449318] [] print_address_description+0x6c/0x234 [ 31.455961] [] kasan_report.cold.6+0x242/0x2fe [ 31.462176] [] ? work_is_static_object+0x39/0x40 [ 31.468554] [] __asan_report_load8_noabort+0x14/0x20 [ 31.475295] [] work_is_static_object+0x39/0x40 [ 31.481782] [] debug_object_activate+0x22d/0x4e0 [ 31.488165] [] ? debug_object_assert_init+0x380/0x380 [ 31.494987] [] ? __wake_up+0x3f/0x50 [ 31.500327] [] __queue_work+0x48/0xf10 [ 31.505840] [] ? p9_pollwake+0x110/0x110 [ 31.511532] [] queue_work_on+0x97/0xa0 [ 31.517140] [] p9_poll_workfn+0x28a/0x330 [ 31.522912] [] process_one_work+0x7e1/0x1500 [ 31.528959] [] ? process_one_work+0x728/0x1500 [ 31.535170] [] ? pwq_dec_nr_in_flight+0x2e0/0x2e0 [ 31.541643] [] worker_thread+0xd6/0x10a0 [ 31.547330] [] ? __schedule+0x655/0x1bd0 [ 31.553013] [] kthread+0x26d/0x300 [ 31.558178] [] ? process_one_work+0x1500/0x1500 [ 31.564479] [] ? kthread_park+0xa0/0xa0 [ 31.570096] [] ? kthread_park+0xa0/0xa0 [ 31.575701] [] ? kthread_park+0xa0/0xa0 [ 31.581300] [] ret_from_fork+0x5c/0x70 [ 31.586812] [ 31.588411] Allocated by task 3806: [ 31.592015] save_stack_trace+0x16/0x20 [ 31.595967] save_stack+0x43/0xd0 [ 31.599478] kasan_kmalloc+0xc7/0xe0 [ 31.603180] kmem_cache_alloc_trace+0xfd/0x2b0 [ 31.607746] p9_fd_create+0xf3/0x330 [ 31.611445] p9_client_create+0x6ff/0x10a0 [ 31.615653] v9fs_session_init+0x333/0x13a0 [ 31.619967] v9fs_mount+0x7d/0x810 [ 31.623485] mount_fs+0x28c/0x370 [ 31.626909] vfs_kern_mount.part.29+0xd1/0x3d0 [ 31.631463] do_mount+0x3c9/0x2740 [ 31.634981] SyS_mount+0xfe/0x110 [ 31.638409] do_syscall_64+0x1a6/0x490 [ 31.642277] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 31.647348] [ 31.648948] Freed by task 3806: [ 31.652212] save_stack_trace+0x16/0x20 [ 31.656158] save_stack+0x43/0xd0 [ 31.659671] kasan_slab_free+0x72/0xc0 [ 31.663529] kfree+0xfb/0x310 [ 31.666612] p9_fd_close+0x298/0x330 [ 31.670299] p9_client_destroy+0x73/0x570 [ 31.674423] v9fs_session_close+0x46/0x110 [ 31.678639] v9fs_kill_super+0x4e/0xa0 [ 31.682503] deactivate_locked_super+0x75/0xd0 [ 31.687069] deactivate_super+0x91/0xd0 [ 31.691026] cleanup_mnt+0xb2/0x160 [ 31.694626] __cleanup_mnt+0x16/0x20 [ 31.698314] task_work_run+0x10c/0x180 [ 31.702173] exit_to_usermode_loop+0xfc/0x120 [ 31.706648] do_syscall_64+0x364/0x490 [ 31.710512] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 31.715582] [ 31.717184] The buggy address belongs to the object at ffff8801c1641180 [ 31.717184] which belongs to the cache kmalloc-512 of size 512 [ 31.729814] The buggy address is located 288 bytes inside of [ 31.729814] 512-byte region [ffff8801c1641180, ffff8801c1641380) [ 31.741680] The buggy address belongs to the page: [ 31.746586] page:ffffea0007059000 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 31.756791] flags: 0x8000000000004080(slab|head) [ 31.761530] page dumped because: kasan: bad access detected [ 31.767212] [ 31.768811] Memory state around the buggy address: [ 31.773712] ffff8801c1641180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.781051] ffff8801c1641200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.788384] >ffff8801c1641280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.795718] ^ [ 31.800100] ffff8801c1641300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.807448] ffff8801c1641380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 31.814800] ================================================================== [ 31.822128] Disabling lock debugging due to kernel taint [ 31.827557] Kernel panic - not syncing: panic_on_warn set ... [ 31.827557] [ 31.834893] CPU: 1 PID: 3812 Comm: kworker/1:2 Tainted: G B 4.9.113-g47bbcd6 #10 [ 31.843524] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.852868] Workqueue: events p9_poll_workfn [ 31.857368] ffff8801b4a8f928 ffffffff81eb32a9 ffffffff843c806f 00000000ffffffff [ 31.865377] 0000000000000000 0000000000000001 0000000000000000 ffff8801b4a8f9e8 [ 31.873371] ffffffff81421a55 0000000041b58ab3 ffffffff843bb788 ffffffff81421896 [ 31.881383] Call Trace: [ 31.883957] [] dump_stack+0xc1/0x128 [ 31.889303] [] panic+0x1bf/0x3bc [ 31.894602] [] ? add_taint.cold.6+0x16/0x16 [ 31.900571] [] ? kasan_end_report+0x32/0x4f [ 31.906538] [] kasan_end_report+0x47/0x4f [ 31.912331] [] kasan_report.cold.6+0x76/0x2fe [ 31.918474] [] ? work_is_static_object+0x39/0x40 [ 31.924868] [] __asan_report_load8_noabort+0x14/0x20 [ 31.931620] [] work_is_static_object+0x39/0x40 [ 31.937832] [] debug_object_activate+0x22d/0x4e0 [ 31.944217] [] ? debug_object_assert_init+0x380/0x380 [ 31.951051] [] ? __wake_up+0x3f/0x50 [ 31.956406] [] __queue_work+0x48/0xf10 [ 31.961931] [] ? p9_pollwake+0x110/0x110 [ 31.967792] [] queue_work_on+0x97/0xa0 [ 31.973319] [] p9_poll_workfn+0x28a/0x330 [ 31.979106] [] process_one_work+0x7e1/0x1500 [ 31.985142] [] ? process_one_work+0x728/0x1500 [ 31.991372] [] ? pwq_dec_nr_in_flight+0x2e0/0x2e0 [ 31.997929] [] worker_thread+0xd6/0x10a0 [ 32.003622] [] ? __schedule+0x655/0x1bd0 [ 32.009321] [] kthread+0x26d/0x300 [ 32.014491] [] ? process_one_work+0x1500/0x1500 [ 32.020794] [] ? kthread_park+0xa0/0xa0 [ 32.026393] [] ? kthread_park+0xa0/0xa0 [ 32.031990] [] ? kthread_park+0xa0/0xa0 [ 32.037599] [] ret_from_fork+0x5c/0x70 [ 32.043694] Dumping ftrace buffer: [ 32.047216] (ftrace buffer empty) [ 32.050908] Kernel Offset: disabled [ 32.054522] Rebooting in 86400 seconds..