kasan: GPF could be caused by NULL-ptr deref or user memory access
FAT-fs (loop1): Directory bread(block 10) failed
 SyS_accept4+0x2c/0x40 net/socket.c:1537
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
general protection fault: 0000 [#1] PREEMPT SMP KASAN
RIP: 0033:0x45a909
Modules linked in:
RSP: 002b:00007ff06f9d7c78 EFLAGS: 00000246
 ORIG_RAX: 0000000000000120
CPU: 0 PID: 13686 Comm: syz-executor.1 Not tainted 4.14.158-syzkaller #0
RAX: ffffffffffffffda RBX: 00007ff06f9d7c90 RCX: 000000000045a909
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
task: ffff888058d2e640 task.stack: ffff8880630d8000
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff06f9d86d4
RIP: 0010:vhost_del_umem_range drivers/vhost/vhost.c:971 [inline]
RIP: 0010:vhost_process_iotlb_msg drivers/vhost/vhost.c:1042 [inline]
RIP: 0010:vhost_chr_write_iter drivers/vhost/vhost.c:1071 [inline]
RIP: 0010:vhost_chr_write_iter+0x4a9/0x1260 drivers/vhost/vhost.c:1055
R13: 00000000004c0b18 R14: 00000000004d44c0 R15: 0000000000000007
RSP: 0018:ffff8880630dfb90 EFLAGS: 00010246
FAT-fs (loop5): Directory bread(block 5) failed
RAX: 0000000000000002 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff84ee88c9 RDI: ffff888044723340
RBP: ffff8880630dfcb0 R08: dffffc0000000000 R09: 0000000000000000
R10: ffff8880630dfb80 R11: ffff888058d2e640 R12: ffff888044727a48
R13: 0000000020000140 R14: ffff888044723280 R15: 0000000000000000
FS:  00007ff7e0411700(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000738000 CR3: 0000000098c4c000 CR4: 00000000001406f0
FAT-fs (loop5): Directory bread(block 6) failed
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 vhost_net_chr_write_iter+0x59/0x70 drivers/vhost/net.c:1365
FAT-fs (loop5): Directory bread(block 7) failed
 call_write_iter include/linux/fs.h:1777 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x4a7/0x6b0 fs/read_write.c:482
 vfs_write+0x198/0x500 fs/read_write.c:544
FAT-fs (loop5): Directory bread(block 8) failed
 SYSC_write fs/read_write.c:590 [inline]
 SyS_write+0xfd/0x230 fs/read_write.c:582
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
FAT-fs (loop5): Directory bread(block 9) failed
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45a909
RSP: 002b:00007ff7e0410c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a909
RDX: 0000000000000068 RSI: 0000000020000280 RDI: 0000000000000005
FAT-fs (loop5): Directory bread(block 10) failed
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff7e04116d4
R13: 00000000004cc167 R14: 00000000004e5f38 R15: 00000000ffffffff
Code: ff ff 48 89 f9 
FAT-fs (loop5): Directory bread(block 11) failed
48 c1 e9 03 80 3c 11 00 0f 85 9c 0c 00 00 
FAT-fs (loop1): Directory bread(block 11) failed
49 8b 8e c0 00 00 00 48 ba 00 00 00 00 00 fc ff df 49 89 cf 48 c1 e9 03 <80> 3c 11 00 0f 85 61 0c 00 00 4d 8b 27 4d 85 e4 0f 84 27 09 00 
RIP: vhost_del_umem_range drivers/vhost/vhost.c:971 [inline] RSP: ffff8880630dfb90
RIP: vhost_process_iotlb_msg drivers/vhost/vhost.c:1042 [inline] RSP: ffff8880630dfb90
RIP: vhost_chr_write_iter drivers/vhost/vhost.c:1071 [inline] RSP: ffff8880630dfb90
RIP: vhost_chr_write_iter+0x4a9/0x1260 drivers/vhost/vhost.c:1055 RSP: ffff8880630dfb90
---[ end trace a992adb71317fdf2 ]---