[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 38.603814] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 39.983743] random: sshd: uninitialized urandom read (32 bytes read) [ 40.296632] random: sshd: uninitialized urandom read (32 bytes read) [ 41.196724] random: sshd: uninitialized urandom read (32 bytes read) [ 41.445598] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.51' (ECDSA) to the list of known hosts. [ 47.155764] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.301539] ================================================================== [ 47.308977] BUG: KMSAN: kernel-infoleak in copy_page_to_iter+0x755/0x1af0 [ 47.315927] CPU: 0 PID: 4575 Comm: blkid Not tainted 4.18.0-rc8+ #34 [ 47.322422] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.331783] Call Trace: [ 47.334407] dump_stack+0x17c/0x1c0 [ 47.338093] kmsan_report+0x188/0x2a0 [ 47.341930] kmsan_internal_check_memory+0x17e/0x1f0 [ 47.347062] kmsan_copy_to_user+0x73/0xb0 executing program [ 47.351273] copy_page_to_iter+0x755/0x1af0 [ 47.355650] generic_file_read_iter+0x3469/0x4430 [ 47.360552] blkdev_read_iter+0x20d/0x270 [ 47.364722] ? blkdev_write_iter+0x5d0/0x5d0 [ 47.369152] __vfs_read+0x7b9/0x9f0 [ 47.372835] vfs_read+0x36c/0x6b0 [ 47.376347] __x64_sys_read+0x1b7/0x3c0 [ 47.380352] ? ksys_read+0x340/0x340 [ 47.384088] do_syscall_64+0x15b/0x220 [ 47.388011] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 47.393213] RIP: 0033:0x7f1c09eca310 [ 47.396929] Code: 73 01 c3 48 8b 0d 28 4b 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d e5 a2 2b 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 6e 8a 01 00 48 89 04 24 [ 47.416454] RSP: 002b:00007fffc69e5088 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 47.424185] RAX: ffffffffffffffda RBX: 000000000000fc00 RCX: 00007f1c09eca310 [ 47.431471] RDX: 0000000000000400 RSI: 0000000000f09868 RDI: 0000000000000003 [ 47.438754] RBP: 0000000000f09840 R08: 0000000000000028 R09: 0000000001680000 [ 47.446036] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000f05030 [ 47.453350] R13: 0000000000000400 R14: 0000000000f05080 R15: 0000000000f09858 [ 47.460639] [ 47.462276] Uninit was created at: [ 47.465842] kmsan_internal_alloc_meta_for_pages+0x146/0x700 [ 47.471653] kmsan_alloc_page+0x75/0xd0 [ 47.475645] __alloc_pages_nodemask+0xf6b/0x5c80 [ 47.480433] alloc_pages_current+0x6b1/0x970 [ 47.484856] __page_cache_alloc+0x95/0x320 [ 47.489109] pagecache_get_page+0xd21/0x13b0 [ 47.493531] grab_cache_page_write_begin+0x10d/0x190 [ 47.498651] block_write_begin+0xf2/0x380 [ 47.502842] blkdev_write_begin+0xf5/0x110 [ 47.507116] generic_perform_write+0x439/0xa20 [ 47.511726] __generic_file_write_iter+0x42a/0x9d0 [ 47.516673] blkdev_write_iter+0x3a3/0x5d0 [ 47.520923] __vfs_write+0x7ac/0xa50 [ 47.524659] vfs_write+0x467/0x8c0 [ 47.528224] __x64_sys_write+0x1b7/0x3c0 [ 47.532308] do_syscall_64+0x15b/0x220 [ 47.536218] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 47.541410] [ 47.543046] Bytes 736-1023 of 1024 are uninitialized [ 47.548161] Memory access starts at ffff8801c1f38c00 [ 47.553382] ================================================================== [ 47.560767] Disabling lock debugging due to kernel taint [ 47.566237] Kernel panic - not syncing: panic_on_warn set ... [ 47.566237] [ 47.573623] CPU: 0 PID: 4575 Comm: blkid Tainted: G B 4.18.0-rc8+ #34 [ 47.581519] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.590888] Call Trace: [ 47.593503] dump_stack+0x17c/0x1c0 [ 47.597154] panic+0x3c3/0x9a0 [ 47.600404] kmsan_report+0x29e/0x2a0 [ 47.604248] kmsan_internal_check_memory+0x17e/0x1f0 [ 47.609383] kmsan_copy_to_user+0x73/0xb0 [ 47.613562] copy_page_to_iter+0x755/0x1af0 [ 47.617939] generic_file_read_iter+0x3469/0x4430 [ 47.622882] blkdev_read_iter+0x20d/0x270 [ 47.627174] ? blkdev_write_iter+0x5d0/0x5d0 [ 47.631624] __vfs_read+0x7b9/0x9f0 [ 47.635295] vfs_read+0x36c/0x6b0 [ 47.638796] __x64_sys_read+0x1b7/0x3c0 [ 47.642835] ? ksys_read+0x340/0x340 [ 47.646567] do_syscall_64+0x15b/0x220 [ 47.650481] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 47.655688] RIP: 0033:0x7f1c09eca310 [ 47.659405] Code: 73 01 c3 48 8b 0d 28 4b 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d e5 a2 2b 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 6e 8a 01 00 48 89 04 24 [ 47.678870] RSP: 002b:00007fffc69e5088 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 47.686593] RAX: ffffffffffffffda RBX: 000000000000fc00 RCX: 00007f1c09eca310 [ 47.693875] RDX: 0000000000000400 RSI: 0000000000f09868 RDI: 0000000000000003 [ 47.701152] RBP: 0000000000f09840 R08: 0000000000000028 R09: 0000000001680000 [ 47.708435] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000f05030 [ 47.715718] R13: 0000000000000400 R14: 0000000000f05080 R15: 0000000000f09858 [ 47.723343] Dumping ftrace buffer: [ 47.726883] (ftrace buffer empty) [ 47.730594] Kernel Offset: disabled [ 47.734212] Rebooting in 86400 seconds..