------------[ cut here ]------------
Trying to write to read-only block-device sda (partno 0)
WARNING: CPU: 1 PID: 426 at block/blk-core.c:705 bio_check_ro block/blk-core.c:705 [inline]
WARNING: CPU: 1 PID: 426 at block/blk-core.c:705 submit_bio_checks+0x146b/0x1ac0 block/blk-core.c:834
Modules linked in:
CPU: 1 PID: 426 Comm: kworker/u4:5 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:bio_check_ro block/blk-core.c:705 [inline]
RIP: 0010:submit_bio_checks+0x146b/0x1ac0 block/blk-core.c:834
Code: 24 48 4c 89 f7 4c 89 44 24 08 45 0f b6 a4 24 e0 05 00 00 e8 27 64 fe ff 48 c7 c7 c0 d1 db 88 48 89 c6 44 89 e2 e8 ef d4 93 04 <0f> 0b 4c 89 fa 4c 8b 44 24 08 48 b8 00 00 00 00 00 fc ff df 48 c1
RSP: 0018:ffffc9000254ecd0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 1ffff920004a9d9f RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff88ddc580 RDI: fffff520004a9d8c
RBP: ffff8881467829a0 R08: 0000000000000001 R09: ffff8880b9f4c827
R10: ffffed10173e9904 R11: 7420676e69797254 R12: 0000000000000000
R13: ffff888015955dd0 R14: ffff888015955dc0 R15: ffff888015955dc8
FS:  0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f95c63f9358 CR3: 000000001e1ee000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 submit_bio_noacct+0x79/0xc90 block/blk-core.c:1046
 __blk_queue_split+0x7d0/0x1350 block/blk-merge.c:350
 blk_mq_submit_bio+0x17c/0x1400 block/blk-mq.c:2146
 __submit_bio_noacct_mq block/blk-core.c:1028 [inline]
 submit_bio_noacct+0x84d/0xc90 block/blk-core.c:1061
 submit_bio+0xdf/0x480 block/blk-core.c:1131
 ext4_io_submit fs/ext4/page-io.c:379 [inline]
 io_submit_add_bh fs/ext4/page-io.c:422 [inline]
 ext4_bio_write_page+0x7c2/0x1b60 fs/ext4/page-io.c:549
 mpage_submit_page+0xe8/0x240 fs/ext4/inode.c:2101
 mpage_map_and_submit_buffers fs/ext4/inode.c:2349 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2488 [inline]
 ext4_writepages+0x1b0d/0x2cf0 fs/ext4/inode.c:2801
 do_writepages+0xca/0x240 mm/page-writeback.c:2352
 __writeback_single_inode+0xd6/0xb30 fs/fs-writeback.c:1461
 writeback_sb_inodes+0x466/0xc40 fs/fs-writeback.c:1723
 __writeback_inodes_wb+0xb2/0x200 fs/fs-writeback.c:1792
 wb_writeback+0x5c1/0x8c0 fs/fs-writeback.c:1898
 wb_check_old_data_flush fs/fs-writeback.c:2000 [inline]
 wb_do_writeback fs/fs-writeback.c:2053 [inline]
 wb_workfn+0x6b8/0xf40 fs/fs-writeback.c:2082
 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2275
 worker_thread+0x598/0xf80 kernel/workqueue.c:2421
 kthread+0x36f/0x450 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296