[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 32.066514] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. [ 33.175067] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 33.606444] random: sshd: uninitialized urandom read (32 bytes read) [ 34.848741] random: sshd: uninitialized urandom read (32 bytes read) [ 35.069124] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.42' (ECDSA) to the list of known hosts. [ 40.543732] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 40.666874] ================================================================== [ 40.674310] BUG: KMSAN: kernel-infoleak in copy_from_read_buf+0x311/0x890 [ 40.681220] CPU: 1 PID: 4537 Comm: syz-executor020 Not tainted 4.17.0+ #19 [ 40.688209] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.697553] Call Trace: [ 40.700128] dump_stack+0x185/0x1d0 [ 40.703738] kmsan_report+0x188/0x2a0 [ 40.707519] kmsan_internal_check_memory+0x17e/0x1f0 [ 40.712611] kmsan_copy_to_user+0x7a/0x160 [ 40.716827] copy_from_read_buf+0x311/0x890 [ 40.721136] ? __msan_metadata_ptr_for_load_8+0x10/0x20 [ 40.726495] n_tty_read+0x178f/0x2f70 [ 40.730284] ? wait_woken+0x2e0/0x2e0 [ 40.734083] ? rcu_all_qs+0x32/0x1f0 [ 40.737791] ? _cond_resched+0x3c/0xd0 [ 40.741675] ? ldsem_down_read+0x95/0xad0 [ 40.745899] ? tty_ldisc_ref_wait+0x97/0xf0 [ 40.750199] ? n_tty_flush_buffer+0x430/0x430 [ 40.754683] tty_read+0x26e/0x6c0 [ 40.758117] ? release_one_tty+0x5f0/0x5f0 [ 40.762345] __vfs_read+0x1b2/0x9d0 [ 40.765956] vfs_read+0x36c/0x6b0 [ 40.769400] __x64_sys_read+0x1bf/0x3e0 [ 40.773353] ? ksys_read+0x360/0x360 [ 40.777053] do_syscall_64+0x15b/0x230 [ 40.780951] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 40.786144] RIP: 0033:0x440ac9 [ 40.789311] RSP: 002b:00007ffeb91207e8 EFLAGS: 00000217 ORIG_RAX: 0000000000000000 [ 40.797017] RAX: ffffffffffffffda RBX: 00007ffeb91208b0 RCX: 0000000000440ac9 [ 40.804275] RDX: 00000000ffffff5c RSI: 0000000020000080 RDI: 0000000000000004 [ 40.811528] RBP: 0000000000000000 R08: 000000000000000a R09: 0000000000000000 [ 40.818780] R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000402390 [ 40.826036] R13: 0000000000402420 R14: 0000000000000000 R15: 0000000000000000 [ 40.833301] [ 40.834910] Uninit was created at: [ 40.838438] kmsan_internal_alloc_meta_for_pages+0x15c/0x710 [ 40.844216] kmsan_alloc_page+0x87/0xe0 [ 40.848184] __alloc_pages_nodemask+0xf7b/0x5cc0 [ 40.852919] alloc_pages_current+0x6b1/0x970 [ 40.857319] __vmalloc_node_range+0x8bf/0x1170 [ 40.861891] vmalloc+0xd8/0xf0 [ 40.865082] n_tty_open+0x4a/0x490 [ 40.868608] tty_ldisc_setup+0x375/0x670 [ 40.872647] tty_init_dev+0xb82/0x1020 [ 40.876511] ptmx_open+0x2bb/0x7c0 [ 40.880030] chrdev_open+0xc25/0xd90 [ 40.883721] do_dentry_open+0xccc/0x1440 [ 40.887757] vfs_open+0x1b6/0x2f0 [ 40.891189] path_openat+0x4771/0x6640 [ 40.895053] do_filp_open+0x261/0x640 [ 40.898831] do_sys_open+0x624/0x960 [ 40.902522] __x64_sys_openat+0x129/0x170 [ 40.906648] do_syscall_64+0x15b/0x230 [ 40.910517] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 40.915678] [ 40.917283] Byte 4094 of 4095 is uninitialized [ 40.921842] Memory access starts at ffffc9000189505e [ 40.926919] ================================================================== [ 40.934357] Disabling lock debugging due to kernel taint [ 40.939790] Kernel panic - not syncing: panic_on_warn set ... [ 40.939790] [ 40.947138] CPU: 1 PID: 4537 Comm: syz-executor020 Tainted: G B 4.17.0+ #19 [ 40.955517] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.964851] Call Trace: [ 40.967425] dump_stack+0x185/0x1d0 [ 40.971045] panic+0x3d0/0x990 [ 40.974221] kmsan_report+0x29e/0x2a0 [ 40.978040] kmsan_internal_check_memory+0x17e/0x1f0 [ 40.983139] kmsan_copy_to_user+0x7a/0x160 [ 40.987368] copy_from_read_buf+0x311/0x890 [ 40.991757] ? __msan_metadata_ptr_for_load_8+0x10/0x20 [ 40.997124] n_tty_read+0x178f/0x2f70 [ 41.000927] ? wait_woken+0x2e0/0x2e0 [ 41.004710] ? rcu_all_qs+0x32/0x1f0 [ 41.008413] ? _cond_resched+0x3c/0xd0 [ 41.012286] ? ldsem_down_read+0x95/0xad0 [ 41.016438] ? tty_ldisc_ref_wait+0x97/0xf0 [ 41.020744] ? n_tty_flush_buffer+0x430/0x430 [ 41.025232] tty_read+0x26e/0x6c0 [ 41.028667] ? release_one_tty+0x5f0/0x5f0 [ 41.032885] __vfs_read+0x1b2/0x9d0 [ 41.036497] vfs_read+0x36c/0x6b0 [ 41.039943] __x64_sys_read+0x1bf/0x3e0 [ 41.043902] ? ksys_read+0x360/0x360 [ 41.047602] do_syscall_64+0x15b/0x230 [ 41.051480] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 41.056649] RIP: 0033:0x440ac9 [ 41.059904] RSP: 002b:00007ffeb91207e8 EFLAGS: 00000217 ORIG_RAX: 0000000000000000 [ 41.067593] RAX: ffffffffffffffda RBX: 00007ffeb91208b0 RCX: 0000000000440ac9 [ 41.074846] RDX: 00000000ffffff5c RSI: 0000000020000080 RDI: 0000000000000004 [ 41.082097] RBP: 0000000000000000 R08: 000000000000000a R09: 0000000000000000 [ 41.089350] R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000402390 [ 41.096598] R13: 0000000000402420 R14: 0000000000000000 R15: 0000000000000000 [ 41.104402] Dumping ftrace buffer: [ 41.107945] (ftrace buffer empty) [ 41.111635] Kernel Offset: disabled [ 41.115236] Rebooting in 86400 seconds..