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 '10.128.10.36' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 43.049511] ================================================================== [ 43.056910] BUG: KMSAN: uninit-value in btrfs_scan_one_device+0x4b6/0x920 [ 43.063823] CPU: 0 PID: 4513 Comm: syzkaller334174 Not tainted 4.16.0+ #85 [ 43.070825] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.080168] Call Trace: [ 43.082762] dump_stack+0x185/0x1d0 [ 43.086389] ? btrfs_scan_one_device+0x4b6/0x920 [ 43.091134] kmsan_report+0x142/0x240 [ 43.094934] __msan_warning_32+0x6c/0xb0 [ 43.098991] btrfs_scan_one_device+0x4b6/0x920 [ 43.103577] btrfs_mount_root+0x332/0x21b0 [ 43.107817] ? kmsan_set_origin+0x9e/0x160 [ 43.112044] ? btrfs_control_open+0x80/0x80 [ 43.116357] mount_fs+0x296/0x780 [ 43.119808] vfs_kern_mount+0x222/0x990 [ 43.123782] btrfs_mount+0x7fe/0x2db0 [ 43.127589] ? kmsan_set_origin+0x9e/0x160 [ 43.131822] ? btrfs_resize_thread_pool+0x5b0/0x5b0 [ 43.136829] mount_fs+0x296/0x780 [ 43.140281] vfs_kern_mount+0x222/0x990 [ 43.144252] do_mount+0xca5/0x4ed0 [ 43.147789] ? __kmalloc+0x23c/0x350 [ 43.151501] ? copy_mount_options+0x91/0x540 [ 43.155909] SYSC_mount+0x32e/0x3d0 [ 43.159535] SyS_mount+0x77/0xa0 [ 43.162897] do_syscall_64+0x309/0x430 [ 43.166780] ? put_mnt_ns+0x2f0/0x2f0 [ 43.170581] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 43.175762] RIP: 0033:0x442e0a [ 43.178939] RSP: 002b:00007ffc268237c8 EFLAGS: 00000217 ORIG_RAX: 00000000000000a5 [ 43.186642] RAX: ffffffffffffffda RBX: 0000000020001758 RCX: 0000000000442e0a [ 43.193903] RDX: 0000000020001200 RSI: 0000000020001240 RDI: 00007ffc268237d0 [ 43.201164] RBP: 0000000000000003 R08: 0000000020001780 R09: 000000000000000a [ 43.208425] R10: 0000000000010000 R11: 0000000000000217 R12: 0000000000000004 [ 43.215684] R13: 0000000000401d00 R14: 0000000000000000 R15: 0000000000000000 [ 43.222947] [ 43.224558] Uninit was stored to memory at: [ 43.228878] kmsan_internal_chain_origin+0x12b/0x210 [ 43.233968] kmsan_memcpy_origins+0x11d/0x170 [ 43.238457] __msan_memcpy+0x109/0x160 [ 43.242341] _copy_to_iter+0x852/0x28f0 [ 43.246309] copy_page_to_iter+0x383/0x1b70 [ 43.250623] shmem_file_read_iter+0x99f/0x1180 [ 43.255193] do_iter_readv_writev+0x84d/0xa00 [ 43.259682] do_iter_read+0x303/0xd70 [ 43.263476] vfs_iter_read+0x118/0x180 [ 43.267355] loop_queue_work+0x270e/0x3ef0 [ 43.271586] kthread_worker_fn+0x58f/0x900 [ 43.275808] loop_kthread_worker_fn+0x90/0xb0 [ 43.280293] kthread+0x539/0x720 [ 43.283654] ret_from_fork+0x35/0x40 [ 43.287348] Uninit was created at: [ 43.290883] kmsan_alloc_meta_for_pages+0x161/0x3a0 [ 43.295892] kmsan_alloc_page+0x82/0xe0 [ 43.299864] __alloc_pages_nodemask+0xf5b/0x5dc0 [ 43.304609] alloc_pages_vma+0xcc8/0x1800 [ 43.308753] shmem_alloc_and_acct_page+0x6d5/0x1000 [ 43.313771] shmem_getpage_gfp+0x35db/0x5770 [ 43.318169] shmem_file_read_iter+0x508/0x1180 [ 43.322747] do_iter_readv_writev+0x84d/0xa00 [ 43.327235] do_iter_read+0x303/0xd70 [ 43.331028] vfs_iter_read+0x118/0x180 [ 43.334904] loop_queue_work+0x270e/0x3ef0 [ 43.339129] kthread_worker_fn+0x58f/0x900 [ 43.343353] loop_kthread_worker_fn+0x90/0xb0 [ 43.347842] kthread+0x539/0x720 [ 43.351197] ret_from_fork+0x35/0x40 [ 43.354897] ================================================================== [ 43.362239] Disabling lock debugging due to kernel taint [ 43.367676] Kernel panic - not syncing: panic_on_warn set ... [ 43.367676] [ 43.375388] CPU: 0 PID: 4513 Comm: syzkaller334174 Tainted: G B 4.16.0+ #85 [ 43.383692] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.393036] Call Trace: [ 43.395618] dump_stack+0x185/0x1d0 [ 43.399240] panic+0x39d/0x940 [ 43.402444] ? btrfs_scan_one_device+0x4b6/0x920 [ 43.407190] kmsan_report+0x238/0x240 [ 43.410985] __msan_warning_32+0x6c/0xb0 [ 43.415039] btrfs_scan_one_device+0x4b6/0x920 [ 43.419618] btrfs_mount_root+0x332/0x21b0 [ 43.423852] ? kmsan_set_origin+0x9e/0x160 [ 43.428079] ? btrfs_control_open+0x80/0x80 [ 43.432391] mount_fs+0x296/0x780 [ 43.435846] vfs_kern_mount+0x222/0x990 [ 43.439822] btrfs_mount+0x7fe/0x2db0 [ 43.443623] ? kmsan_set_origin+0x9e/0x160 [ 43.447851] ? btrfs_resize_thread_pool+0x5b0/0x5b0 [ 43.452861] mount_fs+0x296/0x780 [ 43.456317] vfs_kern_mount+0x222/0x990 [ 43.460287] do_mount+0xca5/0x4ed0 [ 43.463822] ? __kmalloc+0x23c/0x350 [ 43.467528] ? copy_mount_options+0x91/0x540 [ 43.471940] SYSC_mount+0x32e/0x3d0 [ 43.475567] SyS_mount+0x77/0xa0 [ 43.478930] do_syscall_64+0x309/0x430 [ 43.482815] ? put_mnt_ns+0x2f0/0x2f0 [ 43.486610] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 43.491790] RIP: 0033:0x442e0a [ 43.494971] RSP: 002b:00007ffc268237c8 EFLAGS: 00000217 ORIG_RAX: 00000000000000a5 [ 43.502672] RAX: ffffffffffffffda RBX: 0000000020001758 RCX: 0000000000442e0a [ 43.509933] RDX: 0000000020001200 RSI: 0000000020001240 RDI: 00007ffc268237d0 [ 43.517196] RBP: 0000000000000003 R08: 0000000020001780 R09: 000000000000000a [ 43.524461] R10: 0000000000010000 R11: 0000000000000217 R12: 0000000000000004 [ 43.531725] R13: 0000000000401d00 R14: 0000000000000000 R15: 0000000000000000 [ 43.544702] Dumping ftrace buffer: [ 43.549788] (ftrace buffer empty) [ 43.553493] Kernel Offset: disabled [ 43.557094] Rebooting in 86400 seconds..