[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 32.258154] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 37.546869] random: sshd: uninitialized urandom read (32 bytes read) [ 37.888526] random: sshd: uninitialized urandom read (32 bytes read) [ 39.184852] random: sshd: uninitialized urandom read (32 bytes read) [ 39.408766] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.16' (ECDSA) to the list of known hosts. [ 44.978924] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 45.122871] ================================================================== [ 45.130285] BUG: KMSAN: kernel-infoleak in copy_from_read_buf+0x311/0x890 [ 45.137201] CPU: 0 PID: 4551 Comm: syz-executor247 Not tainted 4.17.0+ #16 [ 45.144195] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.153549] Call Trace: [ 45.156141] dump_stack+0x185/0x1d0 [ 45.159763] kmsan_report+0x188/0x2a0 [ 45.163546] kmsan_internal_check_memory+0x138/0x1f0 [ 45.168631] kmsan_copy_to_user+0x7a/0x160 [ 45.172858] copy_from_read_buf+0x311/0x890 [ 45.177159] ? __msan_metadata_ptr_for_load_8+0x10/0x20 [ 45.182513] n_tty_read+0x178f/0x2f70 [ 45.186293] ? wait_woken+0x2e0/0x2e0 [ 45.190077] ? rcu_all_qs+0x32/0x1f0 [ 45.193771] ? _cond_resched+0x3c/0xd0 [ 45.197636] ? ldsem_down_read+0x95/0xad0 [ 45.201764] ? tty_ldisc_ref_wait+0x97/0xf0 [ 45.206906] ? n_tty_flush_buffer+0x430/0x430 [ 45.211388] tty_read+0x26e/0x6c0 [ 45.214822] ? release_one_tty+0x5f0/0x5f0 [ 45.219040] __vfs_read+0x1b2/0x9d0 [ 45.222650] vfs_read+0x36c/0x6b0 [ 45.226086] __x64_sys_read+0x1bf/0x3e0 [ 45.230047] ? ksys_read+0x360/0x360 [ 45.233742] do_syscall_64+0x15b/0x230 [ 45.237625] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 45.242791] RIP: 0033:0x445969 [ 45.245957] RSP: 002b:00007fcda7f09d18 EFLAGS: 00000297 ORIG_RAX: 0000000000000000 [ 45.253644] RAX: ffffffffffffffda RBX: 00000000006dbc5c RCX: 0000000000445969 [ 45.260893] RDX: 00000000ffffff5c RSI: 0000000020000080 RDI: 0000000000000005 [ 45.268140] RBP: 00000000006dbc58 R08: 0000000000000000 R09: 0000000000000000 [ 45.275390] R10: 0000000000000000 R11: 0000000000000297 R12: 6d74702f7665642f [ 45.282640] R13: 00007ffebcfd741f R14: 00007fcda7f0a9c0 R15: 0000000000000001 [ 45.289889] [ 45.291493] Uninit was created at: [ 45.295028] kmsan_alloc_meta_for_pages+0x166/0x3b0 [ 45.300036] kmsan_alloc_page+0x82/0xe0 [ 45.303991] __alloc_pages_nodemask+0xf7b/0x5cc0 [ 45.308728] alloc_pages_current+0x6b1/0x970 [ 45.313114] __vmalloc_node_range+0x8bf/0x1170 [ 45.317673] vmalloc+0xd8/0xf0 [ 45.320848] n_tty_open+0x4a/0x490 [ 45.324374] tty_ldisc_setup+0x375/0x670 [ 45.328412] tty_init_dev+0xb82/0x1020 [ 45.332278] ptmx_open+0x2bb/0x7c0 [ 45.335817] chrdev_open+0xc25/0xd90 [ 45.339509] do_dentry_open+0xccc/0x1440 [ 45.343548] vfs_open+0x1b6/0x2f0 [ 45.346989] path_openat+0x4771/0x6640 [ 45.350858] do_filp_open+0x261/0x640 [ 45.354636] do_sys_open+0x624/0x960 [ 45.358327] __x64_sys_openat+0x129/0x170 [ 45.362467] do_syscall_64+0x15b/0x230 [ 45.366337] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 45.371503] [ 45.373105] Byte 4002 of 4096 is uninitialized [ 45.377662] Memory access starts at ffffc900018b705e [ 45.382736] ================================================================== [ 45.390073] Disabling lock debugging due to kernel taint [ 45.396026] Kernel panic - not syncing: panic_on_warn set ... [ 45.396026] [ 45.403387] CPU: 0 PID: 4551 Comm: syz-executor247 Tainted: G B 4.17.0+ #16 [ 45.411764] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.421097] Call Trace: [ 45.423671] dump_stack+0x185/0x1d0 [ 45.427277] panic+0x3d0/0x990 [ 45.430454] kmsan_report+0x29e/0x2a0 [ 45.434238] kmsan_internal_check_memory+0x138/0x1f0 [ 45.439334] kmsan_copy_to_user+0x7a/0x160 [ 45.443564] copy_from_read_buf+0x311/0x890 [ 45.447864] ? __msan_metadata_ptr_for_load_8+0x10/0x20 [ 45.453207] n_tty_read+0x178f/0x2f70 [ 45.456989] ? wait_woken+0x2e0/0x2e0 [ 45.460773] ? rcu_all_qs+0x32/0x1f0 [ 45.464467] ? _cond_resched+0x3c/0xd0 [ 45.468355] ? ldsem_down_read+0x95/0xad0 [ 45.472485] ? tty_ldisc_ref_wait+0x97/0xf0 [ 45.476784] ? n_tty_flush_buffer+0x430/0x430 [ 45.481263] tty_read+0x26e/0x6c0 [ 45.484699] ? release_one_tty+0x5f0/0x5f0 [ 45.488915] __vfs_read+0x1b2/0x9d0 [ 45.492529] vfs_read+0x36c/0x6b0 [ 45.495962] __x64_sys_read+0x1bf/0x3e0 [ 45.499916] ? ksys_read+0x360/0x360 [ 45.503618] do_syscall_64+0x15b/0x230 [ 45.507485] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 45.512654] RIP: 0033:0x445969 [ 45.515831] RSP: 002b:00007fcda7f09d18 EFLAGS: 00000297 ORIG_RAX: 0000000000000000 [ 45.523517] RAX: ffffffffffffffda RBX: 00000000006dbc5c RCX: 0000000000445969 [ 45.530762] RDX: 00000000ffffff5c RSI: 0000000020000080 RDI: 0000000000000005 [ 45.538012] RBP: 00000000006dbc58 R08: 0000000000000000 R09: 0000000000000000 [ 45.545277] R10: 0000000000000000 R11: 0000000000000297 R12: 6d74702f7665642f [ 45.552530] R13: 00007ffebcfd741f R14: 00007fcda7f0a9c0 R15: 0000000000000001 [ 45.559840] Dumping ftrace buffer: [ 45.563356] (ftrace buffer empty) [ 45.567041] Kernel Offset: disabled [ 45.570645] Rebooting in 86400 seconds..