bisecting fixing commit since 7cc2a8ea104820dd9e702202621e8fd4d9f6c8cf building syzkaller on 510951950dc0ee69cfdaf746061d3dbe31b49fd8 testing commit 7cc2a8ea104820dd9e702202621e8fd4d9f6c8cf with gcc (GCC) 8.4.1 20210217 kernel signature: 1a1d2595ef8b42cb606e33e16b65cfdcc5769cddd33209112c5bdb2507607901 all runs: crashed: WARNING in generic_make_request_checks testing current HEAD 6905b1dc3c32a094f0da61bd656a740f0a97d592 testing commit 6905b1dc3c32a094f0da61bd656a740f0a97d592 with gcc (GCC) 10.2.1 20210217 kernel signature: 7c1825a04ae1b3784848cef247c5d55af45d785a4bc5b81b7ad620b32a1e56cd all runs: crashed: WARNING in submit_bio_checks revisions tested: 2, total time: 19m4.283423102s (build: 12m0.439695s, test: 6m18.28318526s) the crash still happens on HEAD commit msg: Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm crash: WARNING in submit_bio_checks Trying to write to read-only block-device nullb0 (partno 0) WARNING: CPU: 0 PID: 7347 at block/blk-core.c:704 bio_check_ro block/blk-core.c:704 [inline] WARNING: CPU: 0 PID: 7347 at block/blk-core.c:704 submit_bio_checks+0x7de/0x1680 block/blk-core.c:817 Modules linked in: CPU: 1 PID: 7347 Comm: syz-executor.1 Not tainted 5.12.0-rc5-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:704 [inline] RIP: 0010:submit_bio_checks+0x7de/0x1680 block/blk-core.c:817 Code: b6 90 e0 05 00 00 48 8d 74 24 58 4c 89 ff 89 54 24 08 e8 b5 72 fe ff 8b 54 24 08 48 c7 c7 20 b6 10 88 48 89 c6 e8 07 e2 fe 03 <0f> 0b e9 22 fb ff ff 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 48 RSP: 0018:ffffc90004597170 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 1ffff920008b2e35 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffff88129480 RDI: fffff520008b2e20 RBP: ffff88810cd48240 R08: 0000000000000001 R09: ffff8881f64310e7 R10: ffffed103ec8621c R11: 7420676e69797254 R12: ffff88811c859950 R13: ffff88810cd4874c R14: ffff88810c8de000 R15: ffff88811c859940 FS: 0000000000000000(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d4714be8d0 CR3: 000000010154f006 CR4: 00000000001706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: submit_bio_noacct+0x79/0xdb0 block/blk-core.c:1032 submit_bio+0xdf/0x4b0 block/blk-core.c:1118 submit_bh_wbc+0x4e9/0x6a0 fs/buffer.c:3055 __block_write_full_page+0x614/0xdd0 fs/buffer.c:1810 __writepage+0x58/0x140 mm/page-writeback.c:2311 write_cache_pages+0x52b/0xd00 mm/page-writeback.c:2246 generic_writepages mm/page-writeback.c:2337 [inline] generic_writepages+0xd7/0x140 mm/page-writeback.c:2326 do_writepages+0xca/0x240 mm/page-writeback.c:2352 __filemap_fdatawrite_range+0x247/0x320 mm/filemap.c:424 filemap_write_and_wait_range mm/filemap.c:657 [inline] filemap_write_and_wait_range+0xac/0x150 mm/filemap.c:651 filemap_write_and_wait include/linux/fs.h:2753 [inline] __sync_blockdev fs/block_dev.c:522 [inline] sync_blockdev fs/block_dev.c:531 [inline] __blkdev_put+0x59b/0x6c0 fs/block_dev.c:1572 blkdev_put+0x75/0x480 fs/block_dev.c:1641 blkdev_close+0x8b/0xd0 fs/block_dev.c:1649 __fput+0x209/0x870 fs/file_table.c:280 task_work_run+0xc0/0x160 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xac8/0x25b0 kernel/exit.c:825 do_group_exit+0xe7/0x290 kernel/exit.c:922 get_signal+0x3c0/0x1b50 kernel/signal.c:2781 arch_do_signal_or_restart+0x2a8/0x1f80 arch/x86/kernel/signal.c:789 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x1d6/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x40/0x80 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4645a9 Code: Unable to access opcode bytes at RIP 0x46457f. RSP: 002b:00007f10e40fa198 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: 0000000020000000 RBX: 0000000000000000 RCX: 00000000004645a9 RDX: 000000000200000e RSI: 0000000000e7e000 RDI: 0000000020000000 RBP: 000000000050fda0 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000013 R11: 0000000000000246 R12: 000000000055bf00 R13: 00007f10e40fa6bc R14: 00000000ffffffff R15: 0000000000000006 irq event stamp: 9935 hardirqs last enabled at (9985): [] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] hardirqs last enabled at (9985): [] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 hardirqs last disabled at (10090): [] __schedule+0x1225/0x2180 kernel/sched/core.c:4972 softirqs last enabled at (10194): [] invoke_softirq kernel/softirq.c:221 [inline] softirqs last enabled at (10194): [] __irq_exit_rcu kernel/softirq.c:422 [inline] softirqs last enabled at (10194): [] irq_exit_rcu+0x237/0x280 kernel/softirq.c:434 softirqs last disabled at (10205): [] invoke_softirq kernel/softirq.c:221 [inline] softirqs last disabled at (10205): [] __irq_exit_rcu kernel/softirq.c:422 [inline] softirqs last disabled at (10205): [] irq_exit_rcu+0x237/0x280 kernel/softirq.c:434 ---[ end trace e2df024889d9cd1f ]---