[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.584994] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.324456] random: sshd: uninitialized urandom read (32 bytes read) [ 23.740939] random: sshd: uninitialized urandom read (32 bytes read) [ 24.246132] random: sshd: uninitialized urandom read (32 bytes read) [ 24.408284] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.15.206' (ECDSA) to the list of known hosts. [ 29.845250] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program [ 29.962220] ------------[ cut here ]------------ [ 29.967064] generic_make_request: Trying to write to read-only block-device loop0 (partno 0) [ 29.975930] WARNING: CPU: 1 PID: 4396 at block/blk-core.c:2161 generic_make_request_checks+0x1618/0x24a0 [ 29.985550] Kernel panic - not syncing: panic_on_warn set ... [ 29.985550] [ 29.992912] CPU: 1 PID: 4396 Comm: syz-executor533 Not tainted 4.18.0-rc7+ #177 [ 30.000334] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.009665] Call Trace: [ 30.012236] dump_stack+0x1c9/0x2b4 [ 30.015846] ? dump_stack_print_info.cold.2+0x52/0x52 [ 30.021020] panic+0x238/0x4e7 [ 30.024209] ? add_taint.cold.5+0x16/0x16 [ 30.028361] ? __warn.cold.8+0x148/0x1ba [ 30.032406] ? __warn.cold.8+0x117/0x1ba [ 30.036449] ? generic_make_request_checks+0x1618/0x24a0 [ 30.041878] __warn.cold.8+0x163/0x1ba [ 30.045780] ? generic_make_request_checks+0x1618/0x24a0 [ 30.051213] report_bug+0x252/0x2d0 [ 30.054823] do_error_trap+0x1fc/0x4d0 [ 30.058778] ? math_error+0x3e0/0x3e0 [ 30.062566] ? vprintk_default+0x28/0x30 [ 30.066639] ? vprintk_func+0x81/0xe7 [ 30.070438] ? printk+0xa7/0xcf [ 30.073708] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.078532] do_invalid_op+0x1b/0x20 [ 30.082226] invalid_op+0x14/0x20 [ 30.085672] RIP: 0010:generic_make_request_checks+0x1618/0x24a0 [ 30.091765] Code: 8d bd 78 ff ff ff 45 8b b6 d4 04 00 00 48 89 df 4c 89 fe e8 ea 54 07 00 44 89 f2 48 c7 c7 60 16 39 87 48 89 c6 e8 68 30 ff fd <0f> 0b e9 56 ed ff ff 48 8b bd 50 fd ff ff e8 75 f3 71 fe e9 ca ea [ 30.110915] RSP: 0018:ffff8801acc8f640 EFLAGS: 00010282 [ 30.116274] RAX: 0000000000000000 RBX: ffff8801ae5e0400 RCX: 0000000000000000 [ 30.123523] RDX: 0000000000000000 RSI: ffffffff81632481 RDI: 0000000000000001 [ 30.130774] RBP: ffff8801acc8f940 R08: ffff8801ace94500 R09: ffffed003b624fc0 [ 30.138023] R10: ffffed003b624fc0 R11: ffff8801db127e07 R12: ffff8801d3083140 [ 30.145283] R13: ffff8801ae5e0408 R14: 0000000000000000 R15: ffff8801acc8f8b8 [ 30.152543] ? vprintk_func+0x81/0xe7 [ 30.156348] ? kasan_check_read+0x11/0x20 [ 30.160475] ? rcu_is_watching+0x8c/0x150 [ 30.164624] ? blk_init_queue+0x30/0x30 [ 30.168583] ? blk_queue_enter+0xbf7/0xe10 [ 30.172796] ? blk_exit_rl+0x80/0x80 [ 30.176496] ? __save_stack_trace+0x8d/0xf0 [ 30.180820] ? save_stack+0xa9/0xd0 [ 30.184451] ? save_stack+0x43/0xd0 [ 30.188057] ? kasan_kmalloc+0xc4/0xe0 [ 30.191924] ? kasan_slab_alloc+0x12/0x20 [ 30.196050] ? kmem_cache_alloc+0x12e/0x760 [ 30.200352] ? mempool_alloc+0x193/0x4b0 [ 30.204390] ? bio_alloc_bioset+0x39c/0x6f0 [ 30.208797] ? blkdev_issue_flush+0xd1/0x300 [ 30.213187] ? blkdev_fsync+0x93/0xd0 [ 30.216989] ? vfs_fsync_range+0x140/0x220 [ 30.221202] ? do_fsync+0x52/0xa0 [ 30.224640] ? __x64_sys_fsync+0x33/0x40 [ 30.228703] ? do_syscall_64+0x1b9/0x820 [ 30.232743] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 30.238104] ? find_held_lock+0x36/0x1c0 [ 30.242142] generic_make_request+0x2aa/0x1800 [ 30.246750] ? lock_downgrade+0x8f0/0x8f0 [ 30.250890] ? blk_get_request+0x7e0/0x7e0 [ 30.255127] ? kasan_check_read+0x11/0x20 [ 30.259270] ? rcu_is_watching+0x8c/0x150 [ 30.263413] ? do_raw_spin_unlock+0xa7/0x2f0 [ 30.267801] ? rcu_pm_notify+0xc0/0xc0 [ 30.271680] ? rcu_read_lock_sched_held+0x108/0x120 [ 30.276677] ? kmem_cache_alloc+0x5fa/0x760 [ 30.281012] ? mempool_alloc_slab+0x44/0x60 [ 30.285335] ? mempool_free+0x370/0x370 [ 30.289286] ? mempool_alloc_slab+0x44/0x60 [ 30.293589] submit_bio+0xba/0x460 [ 30.297109] ? submit_bio+0xba/0x460 [ 30.300806] ? generic_make_request+0x1800/0x1800 [ 30.305630] ? init_wait_entry+0x1c0/0x1c0 [ 30.309848] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.315366] ? file_check_and_advance_wb_err+0x15a/0x5e0 [ 30.320813] submit_bio_wait+0x134/0x1e0 [ 30.324893] ? submit_bio_wait_endio+0x40/0x40 [ 30.329456] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.334975] blkdev_issue_flush+0x204/0x300 [ 30.339278] blkdev_fsync+0x93/0xd0 [ 30.342884] ? thaw_bdev+0x1a0/0x1a0 [ 30.346617] vfs_fsync_range+0x140/0x220 [ 30.350671] do_fsync+0x52/0xa0 [ 30.353943] __x64_sys_fsync+0x33/0x40 [ 30.357820] do_syscall_64+0x1b9/0x820 [ 30.361700] ? syscall_return_slowpath+0x5e0/0x5e0 [ 30.366618] ? syscall_return_slowpath+0x31d/0x5e0 [ 30.371528] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.377042] ? retint_user+0x18/0x18 [ 30.380745] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.385571] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 30.390739] RIP: 0033:0x444999 [ 30.393938] Code: e8 ec b2 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 bb d4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 30.413097] RSP: 002b:00007ffdc1fbd458 EFLAGS: 00000213 ORIG_RAX: 000000000000004a [ 30.420785] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444999 [ 30.428036] RDX: 0000000000401430 RSI: 0000000000000000 RDI: 0000000000000003 [ 30.435285] RBP: 0000000000000000 R08: 00000000021eb880 R09: 00000000000000c2 [ 30.442531] R10: 000000000000000f R11: 0000000000000213 R12: 00000000000074ed [ 30.449776] R13: 0000000000402370 R14: 0000000000000000 R15: 0000000000000000 [ 30.457394] Dumping ftrace buffer: [ 30.460983] (ftrace buffer empty) [ 30.464680] Kernel Offset: disabled [ 30.468288] Rebooting in 86400 seconds..