INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.30' (ECDSA) to the list of known hosts. executing program executing program executing program syzkaller login: [ 31.146281] ================================================================== [ 31.153655] BUG: KMSAN: uninit-value in copy_page_to_iter+0x754/0x1b70 [ 31.160298] CPU: 0 PID: 3575 Comm: blkid Not tainted 4.16.0+ #83 [ 31.166410] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.175733] Call Trace: [ 31.178298] dump_stack+0x185/0x1d0 [ 31.181898] ? kmsan_internal_check_memory+0x145/0x1d0 [ 31.187146] kmsan_report+0x142/0x240 [ 31.190920] kmsan_internal_check_memory+0x164/0x1d0 [ 31.195996] kmsan_copy_to_user+0x69/0x160 [ 31.200205] copy_page_to_iter+0x754/0x1b70 [ 31.204504] generic_file_read_iter+0x2ee8/0x43f0 [ 31.209331] blkdev_read_iter+0x20d/0x280 [ 31.213455] ? blkdev_write_iter+0x5f0/0x5f0 [ 31.217838] __vfs_read+0x6fb/0x8e0 [ 31.221441] vfs_read+0x36c/0x6c0 [ 31.224873] SYSC_read+0x172/0x360 [ 31.228389] SyS_read+0x55/0x80 [ 31.231643] do_syscall_64+0x309/0x430 [ 31.235503] ? vfs_write+0x8d0/0x8d0 [ 31.239191] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 31.244354] RIP: 0033:0x7f4542388310 [ 31.248037] RSP: 002b:00007ffcdfc6ed78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 31.255716] RAX: ffffffffffffffda RBX: 0000000000000400 RCX: 00007f4542388310 [ 31.262961] RDX: 0000000000000400 RSI: 0000000000bfef48 RDI: 0000000000000003 [ 31.270204] RBP: 0000000000bfef20 R08: 0000000000000028 R09: 0000000001680000 [ 31.277444] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000bfc030 [ 31.284687] R13: 0000000000000400 R14: 0000000000bfc080 R15: 0000000000bfef38 [ 31.291929] [ 31.293526] Uninit was stored to memory at: [ 31.297821] kmsan_internal_chain_origin+0x12b/0x210 [ 31.302895] kmsan_memcpy_origins+0x11d/0x170 [ 31.307366] __msan_memcpy+0x19f/0x1f0 [ 31.311225] _copy_to_iter+0x852/0x28f0 [ 31.315168] copy_page_to_iter+0x383/0x1b70 [ 31.319462] shmem_file_read_iter+0x99f/0x1180 [ 31.324015] do_iter_readv_writev+0x7bb/0x970 [ 31.328481] do_iter_read+0x303/0xd70 [ 31.332252] vfs_iter_read+0x118/0x180 [ 31.336111] loop_queue_work+0x270e/0x3ef0 [ 31.340320] kthread_worker_fn+0x58f/0x900 [ 31.344525] loop_kthread_worker_fn+0x90/0xb0 [ 31.348992] kthread+0x539/0x720 [ 31.352329] ret_from_fork+0x35/0x40 [ 31.356010] Uninit was created at: [ 31.359521] kmsan_alloc_meta_for_pages+0x161/0x3a0 [ 31.364507] kmsan_alloc_page+0x82/0xe0 [ 31.368454] __alloc_pages_nodemask+0xf5b/0x5dc0 [ 31.373182] alloc_pages_vma+0xcc8/0x1800 [ 31.377303] shmem_alloc_and_acct_page+0x6d5/0x1000 [ 31.382292] shmem_getpage_gfp+0x35db/0x5770 [ 31.386674] shmem_file_read_iter+0x508/0x1180 [ 31.391227] do_iter_readv_writev+0x7bb/0x970 [ 31.395694] do_iter_read+0x303/0xd70 [ 31.399467] vfs_iter_read+0x118/0x180 [ 31.403328] loop_queue_work+0x270e/0x3ef0 [ 31.407533] kthread_worker_fn+0x58f/0x900 [ 31.411740] loop_kthread_worker_fn+0x90/0xb0 [ 31.416203] kthread+0x539/0x720 [ 31.419540] ret_from_fork+0x35/0x40 [ 31.423222] [ 31.424819] Bytes 0-1023 of 1024 are uninitialized [ 31.429713] ================================================================== [ 31.437043] Disabling lock debugging due to kernel taint [ 31.442463] Kernel panic - not syncing: panic_on_warn set ... [ 31.442463] [ 31.449796] CPU: 0 PID: 3575 Comm: blkid Tainted: G B 4.16.0+ #83 [ 31.457212] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.466535] Call Trace: [ 31.469096] dump_stack+0x185/0x1d0 [ 31.472695] panic+0x39d/0x940 [ 31.475871] ? kmsan_internal_check_memory+0x145/0x1d0 [ 31.481118] kmsan_report+0x238/0x240 [ 31.484891] kmsan_internal_check_memory+0x164/0x1d0 [ 31.489965] kmsan_copy_to_user+0x69/0x160 [ 31.494174] copy_page_to_iter+0x754/0x1b70 [ 31.498471] generic_file_read_iter+0x2ee8/0x43f0 [ 31.503301] blkdev_read_iter+0x20d/0x280 [ 31.507424] ? blkdev_write_iter+0x5f0/0x5f0 [ 31.511804] __vfs_read+0x6fb/0x8e0 [ 31.515406] vfs_read+0x36c/0x6c0 [ 31.518836] SYSC_read+0x172/0x360 [ 31.522352] SyS_read+0x55/0x80 [ 31.525605] do_syscall_64+0x309/0x430 [ 31.529467] ? vfs_write+0x8d0/0x8d0 [ 31.533156] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 31.538319] RIP: 0033:0x7f4542388310 [ 31.542000] RSP: 002b:00007ffcdfc6ed78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 31.549678] RAX: ffffffffffffffda RBX: 0000000000000400 RCX: 00007f4542388310 [ 31.556919] RDX: 0000000000000400 RSI: 0000000000bfef48 RDI: 0000000000000003 [ 31.564160] RBP: 0000000000bfef20 R08: 0000000000000028 R09: 0000000001680000 [ 31.571401] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000bfc030 [ 31.578641] R13: 0000000000000400 R14: 0000000000bfc080 R15: 0000000000bfef38 [ 31.586331] Dumping ftrace buffer: [ 31.589845] (ftrace buffer empty) [ 31.593526] Kernel Offset: disabled [ 31.597124] Rebooting in 86400 seconds..