------------[ cut here ]------------ generic_make_request: Trying to write to read-only block-device nullb0 (partno 0) WARNING: CPU: 0 PID: 10426 at block/blk-core.c:829 bio_check_ro block/blk-core.c:829 [inline] WARNING: CPU: 0 PID: 10426 at block/blk-core.c:829 generic_make_request_checks+0x1c78/0x2190 block/blk-core.c:930 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 10426 Comm: kworker/u4:2 Not tainted 5.4.0-next-20191126-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+0x197/0x210 lib/dump_stack.c:118 panic+0x2e3/0x75c kernel/panic.c:221 __warn.cold+0x2f/0x35 kernel/panic.c:582 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x37/0x50 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:829 [inline] RIP: 0010:generic_make_request_checks+0x1c78/0x2190 block/blk-core.c:930 Code: 00 00 44 8b ab 5c 05 00 00 48 8d b5 78 ff ff ff 4c 89 ff e8 aa 91 05 00 48 c7 c7 40 9e e5 87 48 89 c6 44 89 ea e8 60 99 10 fe <0f> 0b 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 80 3c 02 RSP: 0018:ffff888059ff7020 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff8880a3239000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815da356 RDI: ffffed100b3fedf6 RBP: ffff888059ff7120 R08: ffff888053e82240 R09: ffffed1015d06621 R10: ffffed1015d06620 R11: ffff8880ae833107 R12: ffff8880a7bc3208 R13: 0000000000000000 R14: 0000000000000001 R15: ffff8880a7bc3200 generic_make_request+0x8f/0xb00 block/blk-core.c:1049 submit_bio+0x113/0x600 block/blk-core.c:1221 submit_bh_wbc+0x6b6/0x900 fs/buffer.c:3172 __block_write_full_page+0x7fe/0x11b0 fs/buffer.c:1844 block_write_full_page+0x21f/0x270 fs/buffer.c:3030 blkdev_writepage+0x25/0x30 fs/block_dev.c:609 __writepage+0x66/0x110 mm/page-writeback.c:2303 write_cache_pages+0x80c/0x13f0 mm/page-writeback.c:2238 generic_writepages mm/page-writeback.c:2329 [inline] generic_writepages+0xed/0x160 mm/page-writeback.c:2318 blkdev_writepages+0x1e/0x30 fs/block_dev.c:2060 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 __writeback_single_inode+0x136/0x1400 fs/fs-writeback.c:1452 writeback_sb_inodes+0x596/0xf20 fs/fs-writeback.c:1716 __writeback_inodes_wb+0xc3/0x260 fs/fs-writeback.c:1785 wb_writeback+0x910/0xd90 fs/fs-writeback.c:1894 wb_check_start_all fs/fs-writeback.c:2018 [inline] wb_do_writeback fs/fs-writeback.c:2044 [inline] wb_workfn+0xb4c/0x1220 fs/fs-writeback.c:2078 process_one_work+0x9af/0x1740 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Kernel Offset: disabled Rebooting in 86400 seconds..