kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 11998 Comm: syz-executor.2 Not tainted 5.4.0-rc7-next-20191115 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mpage_map_and_submit_extent fs/ext4/inode.c:2410 [inline]
RIP: 0010:ext4_writepages+0x17fa/0x2f90 fs/ext4/inode.c:2764
Code: ff ff e8 c9 81 b0 ff 48 8b 85 30 fe ff ff 48 8b 8d 00 fe ff ff 48 8d 78 10 48 89 fa 48 c1 ea 03 0f b6 89 c2 00 00 00 48 d3 e3 <42> 80 3c 2a 00 0f 85 be 16 00 00 48 89 58 10 48 c7 c0 28 24 c5 89
RSP: 0018:ffff888053bbf530 EFLAGS: 00010206
RAX: fffffffffffffff4 RBX: 0000000000040000 RCX: 000000000000000c
RDX: 0000000000000000 RSI: ffffffff8205fbcd RDI: 0000000000000004
RBP: ffff888053bbf760 R08: 0000000000000000 R09: ffffed1015d2703d
R10: ffffed1015d2703c R11: ffff8880ae9381e3 R12: ffff88821594e000
R13: dffffc0000000000 R14: 00000000000007ff R15: ffff88808ab66208
FS:  00007fe00f129700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f939699c000 CR3: 0000000059528000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344
 __filemap_fdatawrite_range+0x2bc/0x3b0 mm/filemap.c:421
 filemap_write_and_wait_range mm/filemap.c:681 [inline]
 filemap_write_and_wait_range+0xfc/0x1d0 mm/filemap.c:675
 iomap_dio_rw+0x646/0x1190 fs/iomap/direct-io.c:466
 ext4_dio_write_iter fs/ext4/file.c:438 [inline]
 ext4_file_write_iter+0x12ee/0x1770 fs/ext4/file.c:545
 call_write_iter include/linux/fs.h:1902 [inline]
 new_sync_write+0x4d3/0x770 fs/read_write.c:483
 __vfs_write+0xe1/0x110 fs/read_write.c:496
 vfs_write+0x268/0x5d0 fs/read_write.c:558
 ksys_write+0x14f/0x290 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:620
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a639
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe00f128c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe00f128c90 RCX: 000000000045a639
RDX: 0000000000043400 RSI: 0000000020000200 RDI: 0000000000000006
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe00f1296d4
R13: 00000000004caf76 R14: 00000000004e3440 R15: 0000000000000007
Modules linked in:
---[ end trace 5615ffec016652ff ]---
RIP: 0010:mpage_map_and_submit_extent fs/ext4/inode.c:2410 [inline]
RIP: 0010:ext4_writepages+0x17fa/0x2f90 fs/ext4/inode.c:2764
Code: ff ff e8 c9 81 b0 ff 48 8b 85 30 fe ff ff 48 8b 8d 00 fe ff ff 48 8d 78 10 48 89 fa 48 c1 ea 03 0f b6 89 c2 00 00 00 48 d3 e3 <42> 80 3c 2a 00 0f 85 be 16 00 00 48 89 58 10 48 c7 c0 28 24 c5 89
RSP: 0018:ffff888053bbf530 EFLAGS: 00010206
RAX: fffffffffffffff4 RBX: 0000000000040000 RCX: 000000000000000c
RDX: 0000000000000000 RSI: ffffffff8205fbcd RDI: 0000000000000004
RBP: ffff888053bbf760 R08: 0000000000000000 R09: ffffed1015d2703d
R10: ffffed1015d2703c R11: ffff8880ae9381e3 R12: ffff88821594e000
R13: dffffc0000000000 R14: 00000000000007ff R15: ffff88808ab66208
FS:  00007fe00f129700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000e71220 CR3: 0000000059528000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400