------------[ cut here ]------------
generic_make_request: Trying to write to read-only block-device nullb0 (partno 0)
WARNING: CPU: 1 PID: 20625 at block/blk-core.c:803 bio_check_ro block/blk-core.c:800 [inline]
WARNING: CPU: 1 PID: 20625 at block/blk-core.c:803 generic_make_request_checks+0x636/0x1540 block/blk-core.c:901
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 20625 Comm: kworker/u4:0 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-251:0)
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 panic+0x264/0x7a9 kernel/panic.c:221
 __warn+0x20e/0x210 kernel/panic.c:582
 report_bug+0x1b6/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:267
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:bio_check_ro block/blk-core.c:800 [inline]
RIP: 0010:generic_make_request_checks+0x636/0x1540 block/blk-core.c:901
Code: 3c 05 00 00 4c 89 f8 48 c1 e8 03 8a 04 08 84 c0 0f 85 f8 0e 00 00 41 8b 17 48 c7 c7 61 2b 61 88 4c 89 f6 31 c0 e8 aa 85 10 fe <0f> 0b e9 2d fc ff ff e8 1e 6c 3e fe c6 05 54 e8 a4 05 01 48 c7 c7
RSP: 0018:ffff888056f8f180 EFLAGS: 00010246
RAX: fe4676018f5e3200 RBX: 0000000000000001 RCX: ffff8880a87324c0
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff888056f8f240 R08: ffffffff815deeb4 R09: ffffed1015d665d8
R10: ffffed1015d665d8 R11: 0000000000000000 R12: 1ffff11014484701
R13: ffff8880a2423808 R14: ffff888056f8f1e0 R15: ffff8880a242e53c
 generic_make_request+0x33/0x980 block/blk-core.c:1020
 submit_bio+0x26b/0x540 block/blk-core.c:1192
 submit_bh_wbc+0x619/0x700 fs/buffer.c:3095
 __block_write_full_page+0x943/0x1070 fs/buffer.c:1767
 block_write_full_page+0x1a4/0x220 include/linux/highmem.h:102
 blkdev_writepage+0x24/0x30 fs/block_dev.c:609
 __writepage+0x63/0xd0 mm/page-writeback.c:2303
 write_cache_pages+0x94a/0xe70 mm/page-writeback.c:2238
 generic_writepages+0x93/0xd0 mm/page-writeback.c:2329
 blkdev_writepages+0x1d/0x30 fs/block_dev.c:2060
 do_writepages+0xfb/0x1f0 mm/page-writeback.c:2344
 __writeback_single_inode+0xd6/0x620 fs/fs-writeback.c:1452
 writeback_sb_inodes+0x948/0x16c0 fs/fs-writeback.c:1716
 __writeback_inodes_wb+0x11e/0x350 fs/fs-writeback.c:1785
 wb_writeback+0x460/0x770 fs/fs-writeback.c:1894
 wb_check_old_data_flush fs/fs-writeback.c:1996 [inline]
 wb_do_writeback fs/fs-writeback.c:2049 [inline]
 wb_workfn+0xa22/0xfb0 fs/fs-writeback.c:2078
 process_one_work+0x7ef/0x10d0 kernel/workqueue.c:2264
 worker_thread+0xc01/0x1630 kernel/workqueue.c:2410
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..