[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.723011] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.576599] random: sshd: uninitialized urandom read (32 bytes read) [ 22.893900] random: sshd: uninitialized urandom read (32 bytes read) [ 23.771577] random: sshd: uninitialized urandom read (32 bytes read) [ 28.609790] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.40' (ECDSA) to the list of known hosts. [ 34.081762] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program [ 34.176011] nf_conntrack: default automatic helper assignment has been turned off for security reasons and CT-based firewall rule not found. Use the iptables CT target to attach helpers instead. [ 34.210527] ================================================================== [ 34.218052] BUG: KASAN: slab-out-of-bounds in pdu_read+0x90/0xd0 [ 34.224204] Read of size 25888 at addr ffff8801c2c7866d by task syz-executor253/4582 [ 34.232076] [ 34.233693] CPU: 1 PID: 4582 Comm: syz-executor253 Not tainted 4.18.0-rc4+ #141 [ 34.241119] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.250455] Call Trace: [ 34.253049] dump_stack+0x1c9/0x2b4 [ 34.256665] ? dump_stack_print_info.cold.2+0x52/0x52 [ 34.261839] ? printk+0xa7/0xcf [ 34.265117] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 34.269861] ? pdu_read+0x90/0xd0 [ 34.273304] print_address_description+0x6c/0x20b [ 34.278131] ? pdu_read+0x90/0xd0 [ 34.281572] kasan_report.cold.7+0x242/0x2fe [ 34.285991] check_memory_region+0x13e/0x1b0 [ 34.290404] memcpy+0x23/0x50 [ 34.293495] pdu_read+0x90/0xd0 [ 34.296761] p9pdu_readf+0x579/0x2170 [ 34.300553] ? p9pdu_writef+0xe0/0xe0 [ 34.304338] ? __fget+0x414/0x670 [ 34.307781] ? rcu_is_watching+0x61/0x150 [ 34.311924] ? expand_files.part.8+0x9c0/0x9c0 [ 34.316506] ? rcu_read_lock_sched_held+0x108/0x120 [ 34.321551] ? p9_fd_show_options+0x1c0/0x1c0 [ 34.326049] p9_client_create+0xde0/0x16c9 [ 34.330288] ? p9_client_read+0xc60/0xc60 [ 34.334425] ? find_held_lock+0x36/0x1c0 [ 34.338570] ? __lockdep_init_map+0x105/0x590 [ 34.343071] ? kasan_check_write+0x14/0x20 [ 34.347295] ? __init_rwsem+0x1cc/0x2a0 [ 34.351268] ? do_raw_write_unlock.cold.8+0x49/0x49 [ 34.356282] ? rcu_read_lock_sched_held+0x108/0x120 [ 34.361285] ? __kmalloc_track_caller+0x5f5/0x760 [ 34.366122] ? save_stack+0xa9/0xd0 [ 34.369735] ? save_stack+0x43/0xd0 [ 34.373355] ? kasan_kmalloc+0xc4/0xe0 [ 34.377242] ? kmem_cache_alloc_trace+0x152/0x780 [ 34.382072] ? memcpy+0x45/0x50 [ 34.385346] v9fs_session_init+0x21a/0x1a80 [ 34.389664] ? find_held_lock+0x36/0x1c0 [ 34.393724] ? v9fs_show_options+0x7e0/0x7e0 [ 34.398131] ? kasan_check_read+0x11/0x20 [ 34.402266] ? rcu_is_watching+0x8c/0x150 [ 34.406401] ? rcu_pm_notify+0xc0/0xc0 [ 34.410286] ? v9fs_mount+0x61/0x900 [ 34.413998] ? rcu_read_lock_sched_held+0x108/0x120 [ 34.419010] ? kmem_cache_alloc_trace+0x616/0x780 [ 34.423882] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 34.429424] v9fs_mount+0x7c/0x900 [ 34.432978] mount_fs+0xae/0x328 [ 34.436337] vfs_kern_mount.part.34+0xdc/0x4e0 [ 34.440916] ? may_umount+0xb0/0xb0 [ 34.444529] ? _raw_read_unlock+0x22/0x30 [ 34.448663] ? __get_fs_type+0x97/0xc0 [ 34.452543] do_mount+0x581/0x30e0 [ 34.456074] ? copy_mount_string+0x40/0x40 [ 34.460309] ? copy_mount_options+0x5f/0x380 [ 34.464704] ? rcu_read_lock_sched_held+0x108/0x120 [ 34.469708] ? kmem_cache_alloc_trace+0x616/0x780 [ 34.474542] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 34.480073] ? _copy_from_user+0xdf/0x150 [ 34.484211] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 34.489744] ? copy_mount_options+0x285/0x380 [ 34.494244] ksys_mount+0x12d/0x140 [ 34.497860] __x64_sys_mount+0xbe/0x150 [ 34.501824] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.506841] do_syscall_64+0x1b9/0x820 [ 34.510730] ? syscall_return_slowpath+0x5e0/0x5e0 [ 34.515645] ? syscall_return_slowpath+0x31d/0x5e0 [ 34.520565] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 34.526105] ? retint_user+0x18/0x18 [ 34.529821] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.534657] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.539840] RIP: 0033:0x440959 [ 34.543012] Code: e8 8c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 3b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 34.562254] RSP: 002b:00007ffc26a283a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 [ 34.569965] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440959 [ 34.577234] RDX: 0000000020000100 RSI: 00000000200000c0 RDI: 0000000000000000 [ 34.584493] RBP: 0000000000000000 R08: 0000000020000180 R09: 00000000004002c8 [ 34.591763] R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000859b [ 34.599035] R13: 0000000000401eb0 R14: 0000000000000000 R15: 0000000000000000 [ 34.606317] [ 34.607932] Allocated by task 4582: [ 34.611574] save_stack+0x43/0xd0 [ 34.615017] kasan_kmalloc+0xc4/0xe0 [ 34.618727] __kmalloc+0x14e/0x760 [ 34.622250] p9_fcall_alloc+0x1e/0x90 [ 34.626041] p9_client_prepare_req.part.8+0x754/0xcd0 [ 34.631214] p9_client_rpc+0x1bd/0x1400 [ 34.635174] p9_client_create+0xd09/0x16c9 [ 34.639408] v9fs_session_init+0x21a/0x1a80 [ 34.643723] v9fs_mount+0x7c/0x900 [ 34.647261] mount_fs+0xae/0x328 [ 34.650630] vfs_kern_mount.part.34+0xdc/0x4e0 [ 34.655199] do_mount+0x581/0x30e0 [ 34.658723] ksys_mount+0x12d/0x140 [ 34.662335] __x64_sys_mount+0xbe/0x150 [ 34.666295] do_syscall_64+0x1b9/0x820 [ 34.670171] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.675345] [ 34.676955] Freed by task 0: [ 34.679953] (stack is not available) [ 34.683644] [ 34.685256] The buggy address belongs to the object at ffff8801c2c78640 [ 34.685256] which belongs to the cache kmalloc-16384 of size 16384 [ 34.698260] The buggy address is located 45 bytes inside of [ 34.698260] 16384-byte region [ffff8801c2c78640, ffff8801c2c7c640) [ 34.710206] The buggy address belongs to the page: [ 34.715127] page:ffffea00070b1e00 count:1 mapcount:0 mapping:ffff8801da802200 index:0x0 compound_mapcount: 0 [ 34.725107] flags: 0x2fffc0000008100(slab|head) [ 34.729767] raw: 02fffc0000008100 ffffea0006cb8808 ffff8801da801c48 ffff8801da802200 [ 34.737645] raw: 0000000000000000 ffff8801c2c78640 0000000100000001 0000000000000000 [ 34.745507] page dumped because: kasan: bad access detected [ 34.751197] [ 34.752809] Memory state around the buggy address: [ 34.757723] ffff8801c2c7a500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 34.765068] ffff8801c2c7a580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 34.772415] >ffff8801c2c7a600: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 34.779766] ^ [ 34.786247] ffff8801c2c7a680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 34.793600] ffff8801c2c7a700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 34.800955] ================================================================== [ 34.808296] Disabling lock debugging due to kernel taint [ 34.813798] Kernel panic - not syncing: panic_on_warn set ... [ 34.813798] [ 34.821174] CPU: 1 PID: 4582 Comm: syz-executor253 Tainted: G B 4.18.0-rc4+ #141 [ 34.830002] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.839372] Call Trace: [ 34.841963] dump_stack+0x1c9/0x2b4 [ 34.845578] ? dump_stack_print_info.cold.2+0x52/0x52 [ 34.850768] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 34.855508] panic+0x238/0x4e7 [ 34.858791] ? add_taint.cold.5+0x16/0x16 [ 34.862923] ? do_raw_spin_unlock+0xa7/0x2f0 [ 34.867318] ? pdu_read+0x90/0xd0 [ 34.870755] kasan_end_report+0x47/0x4f [ 34.874734] kasan_report.cold.7+0x76/0x2fe [ 34.879061] check_memory_region+0x13e/0x1b0 [ 34.883452] memcpy+0x23/0x50 [ 34.886547] pdu_read+0x90/0xd0 [ 34.889817] p9pdu_readf+0x579/0x2170 [ 34.893602] ? p9pdu_writef+0xe0/0xe0 [ 34.897385] ? __fget+0x414/0x670 [ 34.900918] ? rcu_is_watching+0x61/0x150 [ 34.905061] ? expand_files.part.8+0x9c0/0x9c0 [ 34.909640] ? rcu_read_lock_sched_held+0x108/0x120 [ 34.914649] ? p9_fd_show_options+0x1c0/0x1c0 [ 34.919132] p9_client_create+0xde0/0x16c9 [ 34.923365] ? p9_client_read+0xc60/0xc60 [ 34.927520] ? find_held_lock+0x36/0x1c0 [ 34.931574] ? __lockdep_init_map+0x105/0x590 [ 34.936056] ? kasan_check_write+0x14/0x20 [ 34.940275] ? __init_rwsem+0x1cc/0x2a0 [ 34.944232] ? do_raw_write_unlock.cold.8+0x49/0x49 [ 34.949233] ? rcu_read_lock_sched_held+0x108/0x120 [ 34.954233] ? __kmalloc_track_caller+0x5f5/0x760 [ 34.959155] ? save_stack+0xa9/0xd0 [ 34.962766] ? save_stack+0x43/0xd0 [ 34.966374] ? kasan_kmalloc+0xc4/0xe0 [ 34.970248] ? kmem_cache_alloc_trace+0x152/0x780 [ 34.975074] ? memcpy+0x45/0x50 [ 34.978336] v9fs_session_init+0x21a/0x1a80 [ 34.982642] ? find_held_lock+0x36/0x1c0 [ 34.986693] ? v9fs_show_options+0x7e0/0x7e0 [ 34.991097] ? kasan_check_read+0x11/0x20 [ 34.995233] ? rcu_is_watching+0x8c/0x150 [ 34.999364] ? rcu_pm_notify+0xc0/0xc0 [ 35.003247] ? v9fs_mount+0x61/0x900 [ 35.006946] ? rcu_read_lock_sched_held+0x108/0x120 [ 35.011959] ? kmem_cache_alloc_trace+0x616/0x780 [ 35.016815] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 35.022352] v9fs_mount+0x7c/0x900 [ 35.025893] mount_fs+0xae/0x328 [ 35.029246] vfs_kern_mount.part.34+0xdc/0x4e0 [ 35.033824] ? may_umount+0xb0/0xb0 [ 35.037464] ? _raw_read_unlock+0x22/0x30 [ 35.041602] ? __get_fs_type+0x97/0xc0 [ 35.045495] do_mount+0x581/0x30e0 [ 35.049057] ? copy_mount_string+0x40/0x40 [ 35.053303] ? copy_mount_options+0x5f/0x380 [ 35.057875] ? rcu_read_lock_sched_held+0x108/0x120 [ 35.062889] ? kmem_cache_alloc_trace+0x616/0x780 [ 35.067717] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 35.073244] ? _copy_from_user+0xdf/0x150 [ 35.077384] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 35.082923] ? copy_mount_options+0x285/0x380 [ 35.087418] ksys_mount+0x12d/0x140 [ 35.091044] __x64_sys_mount+0xbe/0x150 [ 35.095008] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 35.100038] do_syscall_64+0x1b9/0x820 [ 35.103930] ? syscall_return_slowpath+0x5e0/0x5e0 [ 35.108845] ? syscall_return_slowpath+0x31d/0x5e0 [ 35.113766] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 35.119308] ? retint_user+0x18/0x18 [ 35.123041] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 35.127912] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 35.133092] RIP: 0033:0x440959 [ 35.136263] Code: e8 8c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 3b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 35.155408] RSP: 002b:00007ffc26a283a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 [ 35.163125] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440959 [ 35.170392] RDX: 0000000020000100 RSI: 00000000200000c0 RDI: 0000000000000000 [ 35.177658] RBP: 0000000000000000 R08: 0000000020000180 R09: 00000000004002c8 [ 35.184929] R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000859b [ 35.192194] R13: 0000000000401eb0 R14: 0000000000000000 R15: 0000000000000000 [ 35.200131] Dumping ftrace buffer: [ 35.203663] (ftrace buffer empty) [ 35.207363] Kernel Offset: disabled [ 35.210996] Rebooting in 86400 seconds..