[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 34.939684] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 38.029689] random: sshd: uninitialized urandom read (32 bytes read) [ 38.517595] random: sshd: uninitialized urandom read (32 bytes read) [ 39.902378] random: sshd: uninitialized urandom read (32 bytes read) [ 43.394400] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.4' (ECDSA) to the list of known hosts. [ 48.970770] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program [ 49.159102] ================================================================== [ 49.166523] BUG: KMSAN: kernel-infoleak in copy_from_read_buf+0x311/0x890 [ 49.173444] CPU: 1 PID: 4591 Comm: syz-executor590 Not tainted 4.17.0+ #22 [ 49.180450] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.189800] Call Trace: [ 49.192406] dump_stack+0x185/0x1d0 [ 49.196041] kmsan_report+0x188/0x2a0 [ 49.199851] kmsan_internal_check_memory+0x138/0x1f0 [ 49.204967] kmsan_copy_to_user+0x73/0xb0 executing program [ 49.209119] copy_from_read_buf+0x311/0x890 [ 49.213442] ? __msan_metadata_ptr_for_load_8+0x10/0x20 [ 49.218825] n_tty_read+0x178f/0x2f70 [ 49.222719] ? wait_woken+0x2e0/0x2e0 [ 49.226532] ? rcu_all_qs+0x32/0x1f0 [ 49.230252] ? _cond_resched+0x3c/0xd0 [ 49.234142] ? ldsem_down_read+0x95/0xad0 [ 49.238314] ? tty_ldisc_ref_wait+0x97/0xf0 [ 49.242621] ? n_tty_flush_buffer+0x430/0x430 [ 49.247114] tty_read+0x26e/0x6c0 [ 49.250581] ? release_one_tty+0x5f0/0x5f0 [ 49.254821] __vfs_read+0x1b2/0x9d0 executing program [ 49.258462] vfs_read+0x36c/0x6b0 [ 49.261945] __x64_sys_read+0x1bf/0x3e0 [ 49.265932] ? ksys_read+0x360/0x360 [ 49.269647] do_syscall_64+0x15b/0x230 [ 49.273562] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 49.278751] RIP: 0033:0x4456c9 [ 49.281945] RSP: 002b:00007f98b8df5d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 49.289661] RAX: ffffffffffffffda RBX: 00000000006dac74 RCX: 00000000004456c9 [ 49.296963] RDX: 00000000ffffff5c RSI: 0000000020000080 RDI: 0000000000000008 executing program [ 49.304234] RBP: 00000000006dac70 R08: 0000000000000000 R09: 0000000000000000 [ 49.311505] R10: 0000000000000000 R11: 0000000000000246 R12: 6d74702f7665642f [ 49.318778] R13: 00007ffeacfdf83f R14: 00007f98b8df69c0 R15: 0000000000000001 [ 49.326197] [ 49.327918] Uninit was created at: [ 49.331482] kmsan_internal_alloc_meta_for_pages+0x146/0x700 [ 49.337279] kmsan_alloc_page+0x75/0xd0 [ 49.341412] __alloc_pages_nodemask+0xf7b/0x5cc0 [ 49.346181] alloc_pages_current+0x6b1/0x970 [ 49.350621] __vmalloc_node_range+0x8bf/0x1170 [ 49.355205] vmalloc+0xd8/0xf0 [ 49.358391] n_tty_open+0x4a/0x490 [ 49.362018] tty_ldisc_setup+0x375/0x670 [ 49.366085] tty_init_dev+0xb82/0x1020 [ 49.370061] ptmx_open+0x2bb/0x7c0 [ 49.373605] chrdev_open+0xc25/0xd90 [ 49.377328] do_dentry_open+0xccc/0x1440 [ 49.381384] vfs_open+0x1b6/0x2f0 [ 49.384835] path_openat+0x4771/0x6640 [ 49.388718] do_filp_open+0x261/0x640 [ 49.392727] do_sys_open+0x624/0x960 [ 49.396454] __x64_sys_openat+0x129/0x170 [ 49.400629] do_syscall_64+0x15b/0x230 [ 49.404616] entry_SYSCALL_64_after_hwframe+0x63/0xe7 executing program [ 49.409801] [ 49.411419] Byte 4002 of 4096 is uninitialized [ 49.416011] Memory access starts at ffffc900018af05e [ 49.421195] ================================================================== [ 49.428549] Disabling lock debugging due to kernel taint [ 49.433995] Kernel panic - not syncing: panic_on_warn set ... [ 49.433995] [ 49.441368] CPU: 1 PID: 4591 Comm: syz-executor590 Tainted: G B 4.17.0+ #22 [ 49.449761] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 executing program [ 49.459124] Call Trace: [ 49.461719] dump_stack+0x185/0x1d0 [ 49.465346] panic+0x3d0/0x9b0 [ 49.468568] kmsan_report+0x29e/0x2a0 [ 49.472390] kmsan_internal_check_memory+0x138/0x1f0 [ 49.477515] kmsan_copy_to_user+0x73/0xb0 [ 49.481676] copy_from_read_buf+0x311/0x890 [ 49.486000] ? __msan_metadata_ptr_for_load_8+0x10/0x20 [ 49.491380] n_tty_read+0x178f/0x2f70 [ 49.495189] ? wait_woken+0x2e0/0x2e0 [ 49.499019] ? rcu_all_qs+0x32/0x1f0 [ 49.502762] ? _cond_resched+0x3c/0xd0 [ 49.506652] ? ldsem_down_read+0x95/0xad0 executing program [ 49.510826] ? tty_ldisc_ref_wait+0x97/0xf0 [ 49.515151] ? n_tty_flush_buffer+0x430/0x430 [ 49.519643] tty_read+0x26e/0x6c0 [ 49.523092] ? release_one_tty+0x5f0/0x5f0 [ 49.527322] __vfs_read+0x1b2/0x9d0 [ 49.530979] vfs_read+0x36c/0x6b0 [ 49.534447] __x64_sys_read+0x1bf/0x3e0 [ 49.538429] ? ksys_read+0x360/0x360 [ 49.542143] do_syscall_64+0x15b/0x230 [ 49.546039] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 49.551229] RIP: 0033:0x4456c9 executing program [ 49.554416] RSP: 002b:00007f98b8df5d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 49.562127] RAX: ffffffffffffffda RBX: 00000000006dac74 RCX: 00000000004456c9 [ 49.569395] RDX: 00000000ffffff5c RSI: 0000000020000080 RDI: 0000000000000008 [ 49.576754] RBP: 00000000006dac70 R08: 0000000000000000 R09: 0000000000000000 [ 49.584035] R10: 0000000000000000 R11: 0000000000000246 R12: 6d74702f7665642f [ 49.591313] R13: 00007ffeacfdf83f R14: 00007f98b8df69c0 R15: 0000000000000001 [ 49.599096] Dumping ftrace buffer: [ 49.602637] (ftrace buffer empty) [ 49.606341] Kernel Offset: disabled [ 49.609952] Rebooting in 86400 seconds..