[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 39.657186] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 43.913417] random: sshd: uninitialized urandom read (32 bytes read) [ 44.390353] random: sshd: uninitialized urandom read (32 bytes read) [ 45.272017] random: sshd: uninitialized urandom read (32 bytes read) [ 45.540626] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.45' (ECDSA) to the list of known hosts. [ 51.169453] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 51.301512] ================================================================== [ 51.308927] BUG: KMSAN: uninit-value in btrfs_scan_one_device+0x4c8/0x14e0 [ 51.315944] CPU: 1 PID: 4744 Comm: syz-executor367 Not tainted 4.19.0-rc1+ #39 [ 51.323297] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.332673] Call Trace: [ 51.335268] dump_stack+0x14b/0x190 [ 51.338908] kmsan_report+0x183/0x2b0 [ 51.342713] __msan_warning+0x70/0xc0 [ 51.346517] btrfs_scan_one_device+0x4c8/0x14e0 [ 51.351185] ? rcu_all_qs+0x2e/0x1f0 [ 51.354901] ? _cond_resched+0x38/0xc0 [ 51.358791] ? rcu_all_qs+0x2e/0x1f0 [ 51.362512] btrfs_mount_root+0xcab/0x22e0 [ 51.366746] ? pcpu_alloc+0x1ce1/0x20a0 [ 51.370740] ? btrfs_control_open+0x80/0x80 [ 51.375059] mount_fs+0x28f/0x760 [ 51.378520] vfs_kern_mount+0x21b/0x8d0 [ 51.382502] btrfs_mount+0x8b2/0x2f40 [ 51.386305] ? __msan_metadata_ptr_for_load_4+0x10/0x20 [ 51.391704] ? btrfs_resize_thread_pool+0x5e0/0x5e0 [ 51.396721] mount_fs+0x28f/0x760 [ 51.400180] vfs_kern_mount+0x21b/0x8d0 [ 51.404162] do_mount+0xcee/0x56b0 [ 51.407707] ? copy_mount_options+0x54/0x650 [ 51.412107] ? ksys_mount+0x251/0x3d0 [ 51.415921] ksys_mount+0x32e/0x3d0 [ 51.419552] __x64_sys_mount+0x157/0x1c0 [ 51.423621] ? ksys_mount+0x3d0/0x3d0 [ 51.427438] do_syscall_64+0x15b/0x220 [ 51.431328] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 51.436514] RIP: 0033:0x440029 [ 51.439703] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 51.458602] RSP: 002b:00007fff9182cff8 EFLAGS: 00000217 ORIG_RAX: 00000000000000a5 [ 51.466336] RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 0000000000440029 [ 51.473602] RDX: 0000000020000080 RSI: 0000000020000040 RDI: 0000000020000100 [ 51.480888] RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 [ 51.488158] R10: 0000000000000000 R11: 0000000000000217 R12: 00000000004018b0 [ 51.495425] R13: 0000000000401940 R14: 0000000000000000 R15: 0000000000000000 [ 51.502704] [ 51.504320] Uninit was created at: [ 51.507859] kmsan_internal_alloc_meta_for_pages+0x146/0x700 [ 51.513681] kmsan_alloc_page+0x75/0xd0 [ 51.517682] __alloc_pages_nodemask+0xf6b/0x5c80 [ 51.522475] alloc_pages_current+0x6b1/0x970 [ 51.526889] __page_cache_alloc+0x95/0x320 [ 51.531119] do_read_cache_page+0x829/0x1630 [ 51.535524] read_cache_page_gfp+0xe9/0x120 [ 51.539840] btrfs_scan_one_device+0x297/0x14e0 [ 51.544517] btrfs_mount_root+0xcab/0x22e0 [ 51.548745] mount_fs+0x28f/0x760 [ 51.552193] vfs_kern_mount+0x21b/0x8d0 [ 51.556163] btrfs_mount+0x8b2/0x2f40 [ 51.559960] mount_fs+0x28f/0x760 [ 51.563403] vfs_kern_mount+0x21b/0x8d0 [ 51.567368] do_mount+0xcee/0x56b0 [ 51.570902] ksys_mount+0x32e/0x3d0 [ 51.574520] __x64_sys_mount+0x157/0x1c0 [ 51.578576] do_syscall_64+0x15b/0x220 [ 51.582485] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 51.587673] ================================================================== [ 51.595026] Disabling lock debugging due to kernel taint [ 51.600472] Kernel panic - not syncing: panic_on_warn set ... [ 51.600472] [ 51.607841] CPU: 1 PID: 4744 Comm: syz-executor367 Tainted: G B 4.19.0-rc1+ #39 [ 51.616594] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.625960] Call Trace: [ 51.628548] dump_stack+0x14b/0x190 [ 51.632178] panic+0x35d/0x8cb [ 51.635392] kmsan_report+0x2a8/0x2b0 [ 51.639198] __msan_warning+0x70/0xc0 [ 51.643009] btrfs_scan_one_device+0x4c8/0x14e0 [ 51.647688] ? rcu_all_qs+0x2e/0x1f0 [ 51.651399] ? _cond_resched+0x38/0xc0 [ 51.655292] ? rcu_all_qs+0x2e/0x1f0 [ 51.659020] btrfs_mount_root+0xcab/0x22e0 [ 51.663255] ? pcpu_alloc+0x1ce1/0x20a0 [ 51.667250] ? btrfs_control_open+0x80/0x80 [ 51.671573] mount_fs+0x28f/0x760 [ 51.675036] vfs_kern_mount+0x21b/0x8d0 [ 51.679022] btrfs_mount+0x8b2/0x2f40 [ 51.682830] ? __msan_metadata_ptr_for_load_4+0x10/0x20 [ 51.688220] ? btrfs_resize_thread_pool+0x5e0/0x5e0 [ 51.693239] mount_fs+0x28f/0x760 [ 51.696722] vfs_kern_mount+0x21b/0x8d0 [ 51.700706] do_mount+0xcee/0x56b0 [ 51.704244] ? copy_mount_options+0x54/0x650 [ 51.708670] ? ksys_mount+0x251/0x3d0 [ 51.712494] ksys_mount+0x32e/0x3d0 [ 51.716145] __x64_sys_mount+0x157/0x1c0 [ 51.720237] ? ksys_mount+0x3d0/0x3d0 [ 51.724036] do_syscall_64+0x15b/0x220 [ 51.727926] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 51.733109] RIP: 0033:0x440029 [ 51.736296] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 51.755194] RSP: 002b:00007fff9182cff8 EFLAGS: 00000217 ORIG_RAX: 00000000000000a5 [ 51.762904] RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 0000000000440029 [ 51.770191] RDX: 0000000020000080 RSI: 0000000020000040 RDI: 0000000020000100 [ 51.777459] RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 [ 51.784725] R10: 0000000000000000 R11: 0000000000000217 R12: 00000000004018b0 [ 51.791990] R13: 0000000000401940 R14: 0000000000000000 R15: 0000000000000000 [ 51.799854] Dumping ftrace buffer: [ 51.803396] (ftrace buffer empty) [ 51.807093] Kernel Offset: disabled [ 51.810718] Rebooting in 86400 seconds..