[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 31.630135] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 33.576339] random: sshd: uninitialized urandom read (32 bytes read) [ 34.101563] random: sshd: uninitialized urandom read (32 bytes read) [ 35.336872] random: sshd: uninitialized urandom read (32 bytes read) [ 37.994519] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.49' (ECDSA) to the list of known hosts. [ 43.463883] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 43.579207] ================================================================== [ 43.586608] BUG: KMSAN: uninit-value in copy_page_to_iter+0x754/0x1b70 [ 43.593261] CPU: 1 PID: 4523 Comm: syz-executor535 Not tainted 4.17.0-rc3+ #88 [ 43.600594] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.609925] Call Trace: [ 43.612495] dump_stack+0x185/0x1d0 [ 43.616105] ? kmsan_internal_check_memory+0x155/0x1e0 [ 43.621365] kmsan_report+0x142/0x240 [ 43.625147] kmsan_internal_check_memory+0x174/0x1e0 [ 43.630227] ? copy_page_to_iter+0x5f6/0x1b70 [ 43.634714] kmsan_copy_to_user+0x69/0x160 [ 43.638928] copy_page_to_iter+0x754/0x1b70 [ 43.643240] process_vm_rw_core+0xf6a/0x1930 [ 43.647753] ? process_vm_rw+0x356/0x500 [ 43.651796] process_vm_rw+0x3d5/0x500 [ 43.655667] __x64_sys_process_vm_readv+0x1a0/0x200 [ 43.660669] do_syscall_64+0x154/0x220 [ 43.664535] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 43.669701] RIP: 0033:0x445569 [ 43.672865] RSP: 002b:00007fc373a88da8 EFLAGS: 00000216 ORIG_RAX: 0000000000000136 [ 43.680546] RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 0000000000445569 [ 43.687801] RDX: 0000000000000001 RSI: 0000000020000200 RDI: 00000000000011aa [ 43.695051] RBP: 00000000006dac20 R08: 0000000000000004 R09: 0000000000000000 [ 43.702299] R10: 0000000020000540 R11: 0000000000000216 R12: 0000000000000000 [ 43.709544] R13: 00007ffc0f9c50af R14: 00007fc373a899c0 R15: 0000000000000002 [ 43.716791] [ 43.718390] Uninit was created at: [ 43.721999] kmsan_alloc_meta_for_pages+0x161/0x3a0 [ 43.726998] kmsan_alloc_page+0x82/0xe0 [ 43.730957] __alloc_pages_nodemask+0xf8e/0x5dd0 [ 43.735693] alloc_pages_vma+0x1565/0x1800 [ 43.739901] do_huge_pmd_anonymous_page+0xbdb/0x2550 [ 43.744980] handle_mm_fault+0x428f/0x7e50 [ 43.749193] __do_page_fault+0xec4/0x1a10 [ 43.753317] do_page_fault+0xd3/0x260 [ 43.757100] page_fault+0x1e/0x30 [ 43.760528] [ 43.762129] Bytes 0-161 of 162 are uninitialized [ 43.766853] ================================================================== [ 43.774183] Disabling lock debugging due to kernel taint [ 43.779608] Kernel panic - not syncing: panic_on_warn set ... [ 43.779608] [ 43.786951] CPU: 1 PID: 4523 Comm: syz-executor535 Tainted: G B 4.17.0-rc3+ #88 [ 43.795673] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.805009] Call Trace: [ 43.807587] dump_stack+0x185/0x1d0 [ 43.811197] panic+0x39d/0x940 [ 43.814377] ? kmsan_internal_check_memory+0x155/0x1e0 [ 43.819631] kmsan_report+0x238/0x240 [ 43.823412] kmsan_internal_check_memory+0x174/0x1e0 [ 43.828493] ? copy_page_to_iter+0x5f6/0x1b70 [ 43.832968] kmsan_copy_to_user+0x69/0x160 [ 43.837180] copy_page_to_iter+0x754/0x1b70 [ 43.841483] process_vm_rw_core+0xf6a/0x1930 [ 43.845884] ? process_vm_rw+0x356/0x500 [ 43.849924] process_vm_rw+0x3d5/0x500 [ 43.853795] __x64_sys_process_vm_readv+0x1a0/0x200 [ 43.858790] do_syscall_64+0x154/0x220 [ 43.862664] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 43.867829] RIP: 0033:0x445569 [ 43.870994] RSP: 002b:00007fc373a88da8 EFLAGS: 00000216 ORIG_RAX: 0000000000000136 [ 43.878682] RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 0000000000445569 [ 43.885935] RDX: 0000000000000001 RSI: 0000000020000200 RDI: 00000000000011aa [ 43.893183] RBP: 00000000006dac20 R08: 0000000000000004 R09: 0000000000000000 [ 43.900430] R10: 0000000020000540 R11: 0000000000000216 R12: 0000000000000000 [ 43.907678] R13: 00007ffc0f9c50af R14: 00007fc373a899c0 R15: 0000000000000002 [ 43.915402] Dumping ftrace buffer: [ 43.918921] (ftrace buffer empty) [ 43.922603] Kernel Offset: disabled [ 43.926203] Rebooting in 86400 seconds..