audit: type=1400 audit(1560204930.122:36): avc:  denied  { map } for  pid=7954 comm="syz-executor313" path="/root/syz-executor313285686" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
------------[ cut here ]------------
generic_make_request: Trying to write to read-only block-device nullb0 (partno 0)
WARNING: CPU: 0 PID: 7956 at block/blk-core.c:2175 bio_check_ro block/blk-core.c:2175 [inline]
WARNING: CPU: 0 PID: 7956 at block/blk-core.c:2175 generic_make_request_checks+0x1fc5/0x24c0 block/blk-core.c:2280
audit: type=1400 audit(1560204930.132:37): avc:  denied  { map } for  pid=7954 comm="syz-executor313" path="/dev/nullb0" dev="devtmpfs" ino=15598 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=blk_file permissive=1
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 7956 Comm: syz-executor313 Not tainted 4.19.49 #21
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x263/0x507 kernel/panic.c:185
 __warn.cold+0x20/0x4a kernel/panic.c:540
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x204/0x360 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1013
RIP: 0010:bio_check_ro block/blk-core.c:2175 [inline]
RIP: 0010:generic_make_request_checks+0x1fc5/0x24c0 block/blk-core.c:2280
Code: 85 1f 04 00 00 45 8b b6 e4 04 00 00 48 8d 73 a0 4c 89 e7 e8 5d 58 06 00 48 c7 c7 40 0e 80 87 48 89 c6 44 89 f2 e8 09 e4 2f fe <0f> 0b 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02
RSP: 0018:ffff88808159ef08 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff88808159efd8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8155a186 RDI: ffffed10102b3dd3
RBP: ffff88808159f000 R08: ffff88807f598080 R09: ffffed1015d04fe9
R10: ffffed1015d04fe8 R11: ffff8880ae827f47 R12: ffff8880a0db0480
R13: ffff8880a0db0488 R14: 0000000000000000 R15: 0000000000000000
 generic_make_request+0x24c/0x12d0 block/blk-core.c:2404
 submit_bio+0xba/0x480 block/blk-core.c:2569
 submit_bh_wbc+0x5dc/0x790 fs/buffer.c:3095
 __block_write_full_page+0x76e/0x1020 fs/buffer.c:1766
 block_write_full_page+0x21f/0x270 fs/buffer.c:2956
 blkdev_writepage+0x25/0x30 fs/block_dev.c:581
 __writepage+0x62/0xe0 mm/page-writeback.c:2308
 write_cache_pages+0x971/0x1670 mm/page-writeback.c:2240
 generic_writepages mm/page-writeback.c:2332 [inline]
 generic_writepages+0xe6/0x160 mm/page-writeback.c:2321
 blkdev_writepages+0x1e/0x30 fs/block_dev.c:1965
 do_writepages+0xf3/0x2a0 mm/page-writeback.c:2347
 __filemap_fdatawrite_range+0x26d/0x340 mm/filemap.c:445
 __filemap_fdatawrite mm/filemap.c:453 [inline]
 filemap_fdatawrite mm/filemap.c:458 [inline]
 filemap_write_and_wait mm/filemap.c:617 [inline]
 filemap_write_and_wait+0x47/0xd0 mm/filemap.c:612
 __sync_blockdev fs/block_dev.c:463 [inline]
 sync_blockdev fs/block_dev.c:472 [inline]
 __blkdev_put+0x204/0x810 fs/block_dev.c:1797
 blkdev_put+0x98/0x560 fs/block_dev.c:1866
 blkdev_close+0x8b/0xb0 fs/block_dev.c:1873
 __fput+0x2dd/0x8b0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x933/0x2fa0 kernel/exit.c:876
 do_group_exit+0x135/0x370 kernel/exit.c:979
 get_signal+0x3ec/0x1fc0 kernel/signal.c:2574
 do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x445869
Code: Bad RIP value.
RSP: 002b:00007fd3c106bdb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00000000006dac38 RCX: 0000000000445869
RDX: 0000000000445869 RSI: 0000000000000081 RDI: 00000000006dac3c
RBP: 00000000006dac30 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000006 R11: 0000000000000246 R12: 00000000006dac3c
R13: 00007fffc613e42f R14: 00007fd3c106c9c0 R15: 20c49ba5e353f7cf
Kernel Offset: disabled
Rebooting in 86400 seconds..