[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.789269] 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: [ 23.830272] random: sshd: uninitialized urandom read (32 bytes read) [ 24.377578] random: sshd: uninitialized urandom read (32 bytes read) [ 25.221339] random: sshd: uninitialized urandom read (32 bytes read) [ 25.382194] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.60' (ECDSA) to the list of known hosts. [ 30.806195] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program [ 30.903172] ================================================================== [ 30.910651] BUG: KASAN: slab-out-of-bounds in pdu_read+0x90/0xd0 [ 30.916794] Read of size 32583 at addr ffff8801b63988ad by task syz-executor523/4561 [ 30.924656] [ 30.926285] CPU: 1 PID: 4561 Comm: syz-executor523 Not tainted 4.18.0-rc4+ #140 [ 30.933725] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.943073] Call Trace: [ 30.945663] dump_stack+0x1c9/0x2b4 [ 30.949295] ? dump_stack_print_info.cold.2+0x52/0x52 [ 30.954469] ? printk+0xa7/0xcf [ 30.957740] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 30.962569] ? pdu_read+0x90/0xd0 [ 30.966016] print_address_description+0x6c/0x20b [ 30.970856] ? pdu_read+0x90/0xd0 [ 30.974293] kasan_report.cold.7+0x242/0x2fe [ 30.978698] check_memory_region+0x13e/0x1b0 [ 30.983091] memcpy+0x23/0x50 [ 30.986181] pdu_read+0x90/0xd0 [ 30.989449] p9pdu_readf+0x579/0x2170 [ 30.993236] ? p9pdu_writef+0xe0/0xe0 [ 30.997020] ? __fget+0x414/0x670 [ 31.000462] ? rcu_is_watching+0x61/0x150 [ 31.004591] ? expand_files.part.8+0x9c0/0x9c0 [ 31.009161] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.014170] ? p9_fd_show_options+0x1c0/0x1c0 [ 31.018652] p9_client_create+0xde0/0x16c9 [ 31.022895] ? p9_client_read+0xc60/0xc60 [ 31.027029] ? find_held_lock+0x36/0x1c0 [ 31.031083] ? __lockdep_init_map+0x105/0x590 [ 31.035585] ? kasan_check_write+0x14/0x20 [ 31.039819] ? __init_rwsem+0x1cc/0x2a0 [ 31.043788] ? do_raw_write_unlock.cold.8+0x49/0x49 [ 31.048809] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.053824] ? __kmalloc_track_caller+0x5f5/0x760 [ 31.058662] ? save_stack+0xa9/0xd0 [ 31.062271] ? save_stack+0x43/0xd0 [ 31.065880] ? kasan_kmalloc+0xc4/0xe0 [ 31.069765] ? kmem_cache_alloc_trace+0x152/0x780 [ 31.074600] ? memcpy+0x45/0x50 [ 31.077875] v9fs_session_init+0x21a/0x1a80 [ 31.082182] ? find_held_lock+0x36/0x1c0 [ 31.086234] ? v9fs_show_options+0x7e0/0x7e0 [ 31.090632] ? kasan_check_read+0x11/0x20 [ 31.094769] ? rcu_is_watching+0x8c/0x150 [ 31.098909] ? rcu_pm_notify+0xc0/0xc0 [ 31.102791] ? v9fs_mount+0x61/0x900 [ 31.106496] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.111514] ? kmem_cache_alloc_trace+0x616/0x780 [ 31.116349] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 31.121894] v9fs_mount+0x7c/0x900 [ 31.125424] mount_fs+0xae/0x328 [ 31.128791] vfs_kern_mount.part.34+0xdc/0x4e0 [ 31.133362] ? may_umount+0xb0/0xb0 [ 31.136975] ? _raw_read_unlock+0x22/0x30 [ 31.141110] ? __get_fs_type+0x97/0xc0 [ 31.144985] do_mount+0x581/0x30e0 [ 31.148512] ? copy_mount_string+0x40/0x40 [ 31.152756] ? copy_mount_options+0x5f/0x380 [ 31.157152] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.162156] ? kmem_cache_alloc_trace+0x616/0x780 [ 31.167005] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 31.172549] ? _copy_from_user+0xdf/0x150 [ 31.176689] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.182213] ? copy_mount_options+0x285/0x380 [ 31.186721] ksys_mount+0x12d/0x140 [ 31.190595] __x64_sys_mount+0xbe/0x150 [ 31.194592] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 31.199616] do_syscall_64+0x1b9/0x820 [ 31.203496] ? syscall_return_slowpath+0x5e0/0x5e0 [ 31.208438] ? syscall_return_slowpath+0x31d/0x5e0 [ 31.213367] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 31.218734] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.223564] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 31.228739] RIP: 0033:0x4401a9 [ 31.231907] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 31.251089] RSP: 002b:00007fff3e60d4e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [ 31.258810] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 00000000004401a9 [ 31.266064] RDX: 0000000020000140 RSI: 0000000020000100 RDI: 0000000000000000 [ 31.273318] RBP: 0030656c69662f2e R08: 00000000200002c0 R09: 0000000000000001 [ 31.280573] R10: 0000000000000000 R11: 0000000000000206 R12: 64663d736e617274 [ 31.287830] R13: 0000040000000002 R14: 0000000000000000 R15: 0000000000000000 [ 31.295093] [ 31.296702] Allocated by task 4561: [ 31.300324] save_stack+0x43/0xd0 [ 31.303775] kasan_kmalloc+0xc4/0xe0 [ 31.307469] __kmalloc+0x14e/0x760 [ 31.311009] p9_fcall_alloc+0x1e/0x90 [ 31.314807] p9_client_prepare_req.part.8+0x754/0xcd0 [ 31.320006] p9_client_rpc+0x1bd/0x1400 [ 31.323985] p9_client_create+0xd09/0x16c9 [ 31.328220] v9fs_session_init+0x21a/0x1a80 [ 31.332529] v9fs_mount+0x7c/0x900 [ 31.336053] mount_fs+0xae/0x328 [ 31.339412] vfs_kern_mount.part.34+0xdc/0x4e0 [ 31.343990] do_mount+0x581/0x30e0 [ 31.347518] ksys_mount+0x12d/0x140 [ 31.351143] __x64_sys_mount+0xbe/0x150 [ 31.355116] do_syscall_64+0x1b9/0x820 [ 31.359000] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 31.364172] [ 31.365783] Freed by task 0: [ 31.368790] (stack is not available) [ 31.372503] [ 31.374115] The buggy address belongs to the object at ffff8801b6398880 [ 31.374115] which belongs to the cache kmalloc-16384 of size 16384 [ 31.387258] The buggy address is located 45 bytes inside of [ 31.387258] 16384-byte region [ffff8801b6398880, ffff8801b639c880) [ 31.399213] The buggy address belongs to the page: [ 31.404148] page:ffffea0006d8e600 count:1 mapcount:0 mapping:ffff8801da802200 index:0x0 compound_mapcount: 0 [ 31.414104] flags: 0x2fffc0000008100(slab|head) [ 31.418758] raw: 02fffc0000008100 ffffea0006d88c08 ffff8801da801c48 ffff8801da802200 [ 31.426641] raw: 0000000000000000 ffff8801b6398880 0000000100000001 0000000000000000 [ 31.434507] page dumped because: kasan: bad access detected [ 31.440195] [ 31.441812] Memory state around the buggy address: [ 31.446727] ffff8801b639a780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 31.454081] ffff8801b639a800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 31.461455] >ffff8801b639a880: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc [ 31.468820] ^ [ 31.473215] ffff8801b639a900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 31.480558] ffff8801b639a980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 31.487906] ================================================================== [ 31.495246] Disabling lock debugging due to kernel taint [ 31.500785] Kernel panic - not syncing: panic_on_warn set ... [ 31.500785] [ 31.508144] CPU: 1 PID: 4561 Comm: syz-executor523 Tainted: G B 4.18.0-rc4+ #140 [ 31.516968] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.526307] Call Trace: [ 31.528891] dump_stack+0x1c9/0x2b4 [ 31.532514] ? dump_stack_print_info.cold.2+0x52/0x52 [ 31.537690] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.542447] panic+0x238/0x4e7 [ 31.545620] ? add_taint.cold.5+0x16/0x16 [ 31.549751] ? do_raw_spin_unlock+0xa7/0x2f0 [ 31.554149] ? pdu_read+0x90/0xd0 [ 31.558118] kasan_end_report+0x47/0x4f [ 31.562097] kasan_report.cold.7+0x76/0x2fe [ 31.566401] check_memory_region+0x13e/0x1b0 [ 31.570804] memcpy+0x23/0x50 [ 31.573906] pdu_read+0x90/0xd0 [ 31.577182] p9pdu_readf+0x579/0x2170 [ 31.580972] ? p9pdu_writef+0xe0/0xe0 [ 31.584771] ? __fget+0x414/0x670 [ 31.588209] ? rcu_is_watching+0x61/0x150 [ 31.592349] ? expand_files.part.8+0x9c0/0x9c0 [ 31.596916] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.601917] ? p9_fd_show_options+0x1c0/0x1c0 [ 31.606431] p9_client_create+0xde0/0x16c9 [ 31.610669] ? p9_client_read+0xc60/0xc60 [ 31.614814] ? find_held_lock+0x36/0x1c0 [ 31.618871] ? __lockdep_init_map+0x105/0x590 [ 31.623359] ? kasan_check_write+0x14/0x20 [ 31.627586] ? __init_rwsem+0x1cc/0x2a0 [ 31.631541] ? do_raw_write_unlock.cold.8+0x49/0x49 [ 31.636548] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.641547] ? __kmalloc_track_caller+0x5f5/0x760 [ 31.646371] ? save_stack+0xa9/0xd0 [ 31.649987] ? save_stack+0x43/0xd0 [ 31.653637] ? kasan_kmalloc+0xc4/0xe0 [ 31.657777] ? kmem_cache_alloc_trace+0x152/0x780 [ 31.662601] ? memcpy+0x45/0x50 [ 31.665871] v9fs_session_init+0x21a/0x1a80 [ 31.670182] ? find_held_lock+0x36/0x1c0 [ 31.674231] ? v9fs_show_options+0x7e0/0x7e0 [ 31.678630] ? kasan_check_read+0x11/0x20 [ 31.682767] ? rcu_is_watching+0x8c/0x150 [ 31.686895] ? rcu_pm_notify+0xc0/0xc0 [ 31.690773] ? v9fs_mount+0x61/0x900 [ 31.694486] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.699486] ? kmem_cache_alloc_trace+0x616/0x780 [ 31.704310] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 31.709836] v9fs_mount+0x7c/0x900 [ 31.713365] mount_fs+0xae/0x328 [ 31.716713] vfs_kern_mount.part.34+0xdc/0x4e0 [ 31.721282] ? may_umount+0xb0/0xb0 [ 31.724907] ? _raw_read_unlock+0x22/0x30 [ 31.729041] ? __get_fs_type+0x97/0xc0 [ 31.732926] do_mount+0x581/0x30e0 [ 31.736462] ? copy_mount_string+0x40/0x40 [ 31.740697] ? copy_mount_options+0x5f/0x380 [ 31.745093] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.750095] ? kmem_cache_alloc_trace+0x616/0x780 [ 31.754954] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 31.760486] ? _copy_from_user+0xdf/0x150 [ 31.764622] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.770146] ? copy_mount_options+0x285/0x380 [ 31.774640] ksys_mount+0x12d/0x140 [ 31.778267] __x64_sys_mount+0xbe/0x150 [ 31.782226] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 31.787242] do_syscall_64+0x1b9/0x820 [ 31.791115] ? syscall_return_slowpath+0x5e0/0x5e0 [ 31.796029] ? syscall_return_slowpath+0x31d/0x5e0 [ 31.800963] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 31.806310] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.811134] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 31.816307] RIP: 0033:0x4401a9 [ 31.819473] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 31.838600] RSP: 002b:00007fff3e60d4e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [ 31.846302] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 00000000004401a9 [ 31.853561] RDX: 0000000020000140 RSI: 0000000020000100 RDI: 0000000000000000 [ 31.860816] RBP: 0030656c69662f2e R08: 00000000200002c0 R09: 0000000000000001 [ 31.868072] R10: 0000000000000000 R11: 0000000000000206 R12: 64663d736e617274 [ 31.875351] R13: 0000040000000002 R14: 0000000000000000 R15: 0000000000000000 [ 31.883114] Dumping ftrace buffer: [ 31.886639] (ftrace buffer empty) [ 31.890352] Kernel Offset: disabled [ 31.893980] Rebooting in 86400 seconds..