------------[ cut here ]------------
Trying to write to read-only block-device nullb0 (partno 0)
WARNING: CPU: 1 PID: 8436 at block/blk-core.c:703 bio_check_ro block/blk-core.c:703 [inline]
WARNING: CPU: 1 PID: 8436 at block/blk-core.c:703 submit_bio_checks+0x1641/0x1a70 block/blk-core.c:816
Modules linked in:
CPU: 0 PID: 8436 Comm: syz-executor487 Tainted: G        W         5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:bio_check_ro block/blk-core.c:703 [inline]
RIP: 0010:submit_bio_checks+0x1641/0x1a70 block/blk-core.c:816
Code: 00 00 45 0f b6 a4 24 50 05 00 00 48 8d 74 24 60 48 89 ef e8 c1 46 fe ff 48 c7 c7 00 54 e1 89 48 89 c6 44 89 e2 e8 fc ed 22 05 <0f> 0b e9 51 f3 ff ff e8 b3 40 b9 fd 0f 0b e9 da f1 ff ff e8 a7 40
RSP: 0018:ffffc900017ef488 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88801fae0e50 RCX: 0000000000000000
RDX: ffff888016db1c40 RSI: ffffffff815d7235 RDI: fffff520002fde83
RBP: ffff88802af4b3c0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815d109e R11: 0000000000000000 R12: 0000000000000000
R13: ffff88802af4b3d0 R14: ffff888145646300 R15: ffff88801fae13c4
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc4934896c0 CR3: 000000000be8e000 CR4: 0000000000350ef0
Call Trace:
 submit_bio_noacct+0x81/0xf20 block/blk-core.c:1031
 submit_bio+0x1ea/0x470 block/blk-core.c:1108
 submit_bh_wbc+0x5eb/0x7f0 fs/buffer.c:3050
 __block_write_full_page+0x879/0x1360 fs/buffer.c:1805
 block_write_full_page+0x14d/0x190 fs/buffer.c:2976
 __writepage+0x60/0x180 mm/page-writeback.c:2314
 write_cache_pages+0x754/0x1190 mm/page-writeback.c:2249
 generic_writepages mm/page-writeback.c:2340 [inline]
 generic_writepages+0xe2/0x150 mm/page-writeback.c:2329
 do_writepages+0xec/0x290 mm/page-writeback.c:2355
 __filemap_fdatawrite_range+0x2a5/0x390 mm/filemap.c:413
 filemap_write_and_wait_range mm/filemap.c:686 [inline]
 filemap_write_and_wait_range+0x65/0x100 mm/filemap.c:680
 filemap_write_and_wait include/linux/fs.h:2891 [inline]
 __sync_blockdev fs/block_dev.c:526 [inline]
 sync_blockdev fs/block_dev.c:535 [inline]
 blkdev_put+0x7ff/0xae0 fs/block_dev.c:1530
 blkdev_close+0x8c/0xb0 fs/block_dev.c:1584
 __fput+0x288/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0xbd4/0x2a50 kernel/exit.c:825
 do_group_exit+0x125/0x310 kernel/exit.c:922
 __do_sys_exit_group kernel/exit.c:933 [inline]
 __se_sys_exit_group kernel/exit.c:931 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43da59
Code: Unable to access opcode bytes at RIP 0x43da2f.
RSP: 002b:00007ffdb0bfc3b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00000000004ae230 RCX: 000000000043da59
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 00000000004ae230
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001